Starting Issue After Unrelated Mech Repairs

[PosessionSound26PC]

I have a 1989 Formula 26PC w/ twin Merc 4.3 and Alpha I's. Long story short: starboard engine froze up, shop where I store boat said new motor needed, buddies and I decided to do it ourselves w/ rebuilt motor so prepped by tearing stuff off (exhaust, electrical, etc), decided to look for the "problem" while tearing stuff off and before buying new motor, pulled heads and found nothing, pulled outdrive and both motor and outdrive turned just fine but not when together! Turns out the shop couldn't be bothered to check the gimbal bearing - seized up solidly. I replaced that, replaced exhaust components, repainted intake and heads, etc. Got everything back together.

Went to start it - dead batteries due to my ignorance about needing to keep deep cycle batteries charged/topped off. Bought new deep cycle batteries and installed. Blowers work, lights work, all accessories work. But when starting either motor (including port which I never touched in any way), nothing happens except a clicking noise at what I determined were the Starter Slave Solenoids mounted on the same bracket as the Mercathode systems and the 50amp engine circuit breakers (one each on both motors). Both solenoids make a clicking noise but nothing happens thereafter - no starter movement or noise.

I didn't have a volt meter with me so couldn't check if battery voltage dropped below 12V when ignition switched is turned but assume batteries are good as they are brand new!? What else could it be? The boat has been sitting for two years, covered. I assume the starters are sealed units and unlikely to corrode? Weird that port motor won't turn over either - makes me suspect batteries or some other common component but don't know where to look. Any trouble shooting hints besides voltage check while turning key? Much appreciated.

Edit: when turning the key for starboard, boat voltage indicator pegged at 16V (max). When turning key for port, voltage meter read something like 11V. Mean anything? I double checked that both my batteries were wired properly (black to black, red to red...).

 

[Scott06]

I have a 1989 Formula 26PC w/ twin Merc 4.3 and Alpha I's. Long story short: starboard engine froze up, shop where I store boat said new motor needed, buddies and I decided to do it ourselves w/ rebuilt motor so prepped by tearing stuff off (exhaust, electrical, etc), decided to look for the "problem" while tearing stuff off and before buying new motor, pulled heads and found nothing, pulled outdrive and both motor and outdrive turned just fine but not when together! Turns out the shop couldn't be bothered to check the gimbal bearing - seized up solidly. I replaced that, replaced exhaust components, repainted intake and heads, etc. Got everything back together.

Went to start it - dead batteries due to my ignorance about needing to keep deep cycle batteries charged/topped off. Bought new deep cycle batteries and installed. Blowers work, lights work, all accessories work. But when starting either motor (including port which I never touched in any way), nothing happens except a clicking noise at what I determined were the Starter Slave Solenoids mounted on the same bracket as the Mercathode systems and the 50amp engine circuit breakers (one each on both motors). Both solenoids make a clicking noise but nothing happens thereafter - no starter movement or noise.

I didn't have a volt meter with me so couldn't check if battery voltage dropped below 12V when ignition switched is turned but assume batteries are good as they are brand new!? What else could it be? The boat has been sitting for two years, covered. I assume the starters are sealed units and unlikely to corrode? Weird that port motor won't turn over either - makes me suspect batteries or some other common component but don't know where to look. Any trouble shooting hints besides voltage check while turning key? Much appreciated.

Edit: when turning the key for starboard, boat voltage indicator pegged at 16V (max). When turning key for port, voltage meter read something like 11V. Mean anything? I double checked that both my batteries were wired properly (black to black, red to red...).

So everything turned over ok until you changed batteries? Wouks start by cleaning and tightening all positive and negative battery connections including ones at the starters down low…

 

[San_Diego_SeaRay]

Quick useful diagnostic tip: Take a pair of jumper cables and connect the end of one color to the negative battery terminal. Take the other end of the same color and clamp it to the engine block near or even better on to the body of the starter. Be careful not to touch the either of the "red" lugs with this end. Try turning the engine over. If it sounds noticeably better than before, then you know that your ground cable has an issue or that the starter isn't grounding properly against the block (this happened to me once when sea water dripped from the manifolds down into the gap btwn starter and block and corroded the contact surfaces).

 

[PosessionSound26PC]

So everything turned over ok until you changed batteries? Wouks start by cleaning and tightening all positive and negative battery connections including ones at the starters down low…

Well, last time I started the boat was 2 years ago so... Yes, likely corrosion so will have to find a way to squeeze myself down in that space... ugh.

 

[PosessionSound26PC]

Quick useful diagnostic tip: Take a pair of jumper cables and connect the end of one color to the negative battery terminal. Take the other end of the same color and clamp it to the engine block near or even better on to the body of the starter. Be careful not to touch the either of the "red" lugs with this end. Try turning the engine over. If it sounds noticeably better than before, then you know that your ground cable has an issue or that the starter isn't grounding properly against the block (this happened to me once when sea water dripped from the manifolds down into the gap btwn starter and block and corroded the contact surfaces).

Will definitely try this! Thanks.

 

[PosessionSound26PC]

So everything turned over ok until you changed batteries? Wouks start by cleaning and tightening all positive and negative battery connections including ones at the starters down low…

Took a look at the connections on both both starters - I thought I would find at least some corrosion but everything looks clean/nice. Didn't see any obvious corrosion on any wires or connections all the way to the battery. The starters themselves do have corrosion on their lower surfaces, a fair bit of the paint is peeling off due to that. I need to get some alligator clips for my voltmeter so I can check voltage down at the starter connections.

 

[PosessionSound26PC]

Quick useful diagnostic tip: Take a pair of jumper cables and connect the end of one color to the negative battery terminal. Take the other end of the same color and clamp it to the engine block near or even better on to the body of the starter. Be careful not to touch the either of the "red" lugs with this end. Try turning the engine over. If it sounds noticeably better than before, then you know that your ground cable has an issue or that the starter isn't grounding properly against the block (this happened to me once when sea water dripped from the manifolds down into the gap btwn starter and block and corroded the contact surfaces).

I went to try this yesterday and it didn't seem to make any difference but on the way home I realized I wasn't thinking - I have two motors, two batteries and what appear to me to be two different electrical systems, and I didn't think to check and make sure I was connected to the battery that corresponds to that motor! I had assumed that both systems were joined together so that if one battery died, the other could still start both motors and one alternator could charge both batteries. Is this not the case? If they are separate, which system do the accessories run off of?

 

[San_Diego_SeaRay]

I went to try this yesterday and it didn't seem to make any difference but on the way home I realized I wasn't thinking - I have two motors, two batteries and what appear to me to be two different electrical systems, and I didn't think to check and make sure I was connected to the battery that corresponds to that motor! I had assumed that both systems were joined together so that if one battery died, the other could still start both motors and one alternator could charge both batteries. Is this not the case? If they are separate, which system do the accessories run off of?

Do you have a multimeter? You can verify that the neg terminal corresponds to a specific engine by measuring Ohm resistance between the negative terminal and the engine block. I would expect less than 0.5 Ohms of resistance. However, something higher might indicate exactly what you're looking for: the inability for enough amps to pass from battery to starter due to a bad connection/too high resistance. If it shows "infinite" resistance, then that engine block is not connected to that battery.

 

[PosessionSound26PC]

Do you have a multimeter? You can verify that the neg terminal corresponds to a specific engine by measuring Ohm resistance between the negative terminal and the engine block. I would expect less than 0.5 Ohms of resistance. However, something higher might indicate exactly what you're looking for: the inability for enough amps to pass from battery to starter due to a bad connection/too high resistance. If it shows "infinite" resistance, then that engine block is not connected to that battery.

Got it - another useful trick. I have a meter and will check it out in the next day or two. Any thoughts on the edit to my original post? I have separate voltage gauges for each motor/battery/system. The port measures 12v when I turn the key to ON, but the starboard pegs to max. Seems very odd - didn't have a multimeter on me at the time but will check this as well.

 

[San_Diego_SeaRay]

Got it - another useful trick. I have a meter and will check it out in the next day or two. Any thoughts on the edit to my original post? I have separate voltage gauges for each motor/battery/system. The port measures 12v when I turn the key to ON, but the starboard pegs to max. Seems very odd - didn't have a multimeter on me at the time but will check this as well.

Pegging to max is definitely odd. I would just use a multimeter to verify true voltage.

Regarding whether or not you have true truly separate electrical systems, this should also be a simple test. If you check resistance from one engine block to another, if it is ~0.5 - 3.0 ohms then they are not separate systems. If they show infinite resistance, then they are unconnected and separate systems. Try to find bare iron metal to do this test.

 

[PosessionSound26PC]

Pegging to max is definitely odd. I would just use a multimeter to verify true voltage.

Regarding whether or not you have true truly separate electrical systems, this should also be a simple test. If you check resistance from one engine block to another, if it is ~0.5 - 3.0 ohms then they are not separate systems. If they show infinite resistance, then they are unconnected and separate systems. Try to find bare iron metal to do this test.

Ok, did some more troubleshooting - here are the long winded results:

1. Checked resistance from both starter housings to their respective blocks: both 0.4 ohms, so good contact between starters and ground.

2. Checked resistance from BOTH blocks to BOTH negative terminals that get bolted to the battery terminals - both 0.3 ohms. So not only good contact but also ONE system? Also checked block to block and got same result.

3. Hooked up ONE battery only - all accessories worked when turning EITHER key to ON and got slave solenoid clicks when turning EITHER key to START. So again, ONE system. Still got 12V on port motor voltage indicator and pegged on starboard indicator.

Now here's where it gets weird:

4. I thought maybe it was the switch that prevents turning on the motor when the gear shift is engaged (not in neutral) since I had removed and re-installed the shifter bracket (I did not take it apart, just took it off the exhaust riser to which it's mounted). But Mercruiser manual seems to show that this switch is in the shifter handle assembly at the helm? Or is it this "cut-out" switch in the shifter bracket assembly above the motors? From what I could tell, the switch at the bracket on the motors did not change state when either drive was shifted in either direction... what is the switch for and how does it activate? I double-checked the shifter controls at the helm, cycled them and made sure they were in the middle/neutral position. Still just clicks when STARTING.

5. While playing with the accessories while the starboard motor key was set to ON, I got a loud alarm maybe 30 seconds after turning the key to ON. There's an inscription on the dash that says a low oil pressure or overheat alarm can sound in those cases. Related to this: while taking the upper part of the starboard motor apart (to search for my non-motor problem noted in the original post) I accidentally broke off the end of the water temperature sensor that screws into the side of the thermostat housing - it was corroded and trying to turn the nut to get the wires off broke the stud off the sensor. I purchased a new sensor which looked like the old one and installed it with the same two wires.

Is it possible that this sensor is the wrong one, broken, or that I somehow screwed up the installation and it's now giving an overheat signal when there is none? I purchased this one which has the same Airpax P/N on it as my old one: Link. I suppose I might have to take it out and test it in some boiling water, or test it in place and compare against port side sensor. It looks identical though. Would there be TWO audio alarms, one for each motor? Since they are audible alarms only, you would not know which motor was overheating... If only one alarm, would it be wired such that neither motor could turn on until the alarm condition was cleared? THAT might explain why I can't turn either motor on...

Also, at some point during all this, the starboard voltage indicator started to work again and no longer pegs to max - it shows 12v now. Not sure when that started to work but still no turning over. Thoughts?

 

[PosessionSound26PC]

Hmm, scratch that about the water temperature switch - was just looking at the Merc manual and the testing procedure for the Audio Warning System Buzzer is to 1) Turn key to ON position, 2) Wait 7-14 seconds for horn to sound. Guess I installed the right sensor switch and did it correctly

 

[dubs283]

There is a troubleshooting guide for a no start situation in the stickies, top of forum page. Read through it to understand the engines starting system. Lots of good info there

 

[San_Diego_SeaRay]

Now here's where it gets weird:

4. I thought maybe it was the switch that prevents turning on the motor when the gear shift is engaged (not in neutral) since I had removed and re-installed the shifter bracket (I did not take it apart, just took it off the exhaust riser to which it's mounted).

Didn't you hear the remote starting solenoid click when you turned the key? If so, then it's not your Neutral Safety Switch. The problem is downstream from there.

5. While playing with the accessories while the starboard motor key was set to ON, I got a loud alarm maybe 30 seconds after turning the key to ON. There's an inscription on the dash that says a low oil pressure or overheat alarm can sound in those cases. Related to this: while taking the upper part of the starboard motor apart (to search for my non-motor problem noted in the original post) I accidentally broke off the end of the water temperature sensor that screws into the side of the thermostat housing - it was corroded and trying to turn the nut to get the wires off broke the stud off the sensor. I purchased a new sensor which looked like the old one and installed it with the same two wires.

You're confusing the issue here. On your ignition switch (key), you have 3 modes: OFF/RUN/START. Accessories ONLY run during the RUN mode. You are troubleshooting the START circuit, which is a completely separate circuit than the RUN circuit. When you start your engine, you temporarily use the START circuit to start the engine and the key immediately springs back to the RUN circuit once the engine is running. Again, you need to troubleshoot the START circuit, not the RUN circuit so don't get distracted by it.

Also, an alarm while the key is in RUN mode and the engine is off is completely normal and in fact indicates that the alarm is working exactly as it should.

Also, at some point during all this, the starboard voltage indicator started to work again and no longer pegs to max - it shows 12v now. Not sure when that started to work but still no turning over. Thoughts?

At work so don't have time to elaborate but I'll try to post add'l ideas later today.

 

[PosessionSound26PC]

There is a troubleshooting guide for a no start situation in the stickies, top of forum page. Read through it to understand the engines starting system. Lots of good info there

Thanks, I'll check it out. Also ran across the one in the Merc manual last night.

 

[San_Diego_SeaRay]

At work so don't have time to elaborate but I'll try to post add'l ideas later today.

Here are my suggestions at this point:

• Forget about the question of whether or not the two circuits are separate or not; it’s not relevant at this point. You’re trying to get at least one engine started. It *should* be really easy regardless if the systems are interconnected or not
• Forget about accessories and what they indicate. Accessories only run off the RUN circuit. You’re not having problems with the RUN circuit. You’re having problems w. the START circuit.
• First thing I would do now is to check to see if you’re getting 12V at the starter when turning the ignition to start. You would need to connect a multimeter to the “start” solenoid terminal and to ground. You say that you DO hear the remote solenoid click (I’m assuming it’s on the engine) when you turn the key to Start. So you know that the circuit works at least up until that point. It only has about 2 more feet to travel down to the starter from there. So verify that it does transmit the 12V down to the starter terminal.
• Assuming you get 12V at the starter terminal, you can hook the battery up directly to the engine. Cut out any switches or gauges in between. You mentioned you have a voltage meter in the circuit. It’s not required for starting. So just hook up the red cable directly to the large lug on the starter and the black cable should already be hooked up to a stud on the flywheel housing. Make sure all the other wires also stay connected to the red lug. Try to start the engine with this configuration. Tip: If it’s too hard to measure voltage at the starter terminal, you can use a jumper wire with alligator clips to make it easier to access this voltage reading by clipping one end of the jumper wire to the terminal and measuring the other end w. the multimeter

 

[PosessionSound26PC]

Here are my suggestions at this point:

• Forget about the question of whether or not the two circuits are separate or not; it’s not relevant at this point. You’re trying to get at least one engine started. It *should* be really easy regardless if the systems are interconnected or not
• Forget about accessories and what they indicate. Accessories only run off the RUN circuit. You’re not having problems with the RUN circuit. You’re having problems w. the START circuit.
• First thing I would do now is to check to see if you’re getting 12V at the starter when turning the ignition to start. You would need to connect a multimeter to the “start” solenoid terminal and to ground. You say that you DO hear the remote solenoid click (I’m assuming it’s on the engine) when you turn the key to Start. So you know that the circuit works at least up until that point. It only has about 2 more feet to travel down to the starter from there. So verify that it does transmit the 12V down to the starter terminal.
• Assuming you get 12V at the starter terminal, you can hook the battery up directly to the engine. Cut out any switches or gauges in between. You mentioned you have a voltage meter in the circuit. It’s not required for starting. So just hook up the red cable directly to the large lug on the starter and the black cable should already be hooked up to a stud on the flywheel housing. Make sure all the other wires also stay connected to the red lug. Try to start the engine with this configuration. Tip: If it’s too hard to measure voltage at the starter terminal, you can use a jumper wire with alligator clips to make it easier to access this voltage reading by clipping one end of the jumper wire to the terminal and measuring the other end w. the multimeter

Good tips, thanks for clarifying what is essential and what isn't. Might be a little tricky getting jumper cables into that tight spot at the starter but will try. Should be able to find some long test leads w/ alligator clips at work and test them out Friday or some time this weekend. Thanks!

 

[San_Diego_SeaRay]

Not jumper cables. These little jumper wires. You can buy them a Harbor Freight, etc.



Yeah, it would be tough to get jumper cables on that little terminal.

 

[PosessionSound26PC]

Not jumper cables. These little jumper wires. You can buy them a Harbor Freight, etc.

View attachment 365600

Yeah, it would be tough to get jumper cables on that little terminal.

Ok, here are my latest results after buying some long test clips as you show above:

1. I confirmed 12v supply via the thick red wires to each starter.
2. Since I already established that the slave solenoids were 'clicking', I checked and confirmed both solenoids output 12v output all the way down to the starter solenoid when the key was turned to START.

So both starters should be getting juice and a trigger signal from the slave solenoid - everything checks out except the starters themselves. The connections look good but the starters themselves are fairly rusty; it's possible this has penetrated them or their solenoid switches. I think they are original so 30 years old...

One other detail that I also noticed last time but only briefly and couldn't decide what I had heard: a distinct arcing noise like when you push the ignitor on your bbq to light the gas - a repetitive electric arc/click. But only the port motor as far as I could tell and only sometimes when I turned the key to START.

I assume I either need new starters and/or solenoids and will plan on pulling one to inspect pending your agreement

Thanks.

 

[stang32]

for the time being, forget about all those other "issues" you spoke of and focus on the starter circuit only and lets recap:
your starters are 30 years old,
have not been used in 2 years,
you have power going from the solenoid to the stsrter on the yellow/red wire when the key is turned to start
you have battery + 12V going to the large lug on the starter
you have good grounds

all roads lead to needing a new starter.

just a little side note on this subject:
when i rebuild or replace a motor, i make it a ritual to strap it down on a trailer or something solid and run it , with water running through it, tune it and make it plug and play ready. you can save yourself a lot of time doing such.
good luck