Hot Start/Electical Problem

[EddiePetty]

Re: Hot Start/Electical Problem

......The blower has a direct ground to the starter bolt. The bilge pump also has a direct ground to the starter bolt.....

....kinda sounds like the main ground cable to the engine block has a loose (electrically) connection or a point of high resistence.

 

[wire2]

Re: Hot Start/Electical Problem

This should be very easy to solve;

When it's warm and your electrics stop working,
1. check battery voltage. ~12v?
2. if yes, turn the blower switch on. Is there +12v between batt ground to both terminals of that switch?
3. if yes, check between batt neg post to engine. 0 volts?
4. if yes, check between eng and neg blower lead. 0 volts?

If all of the above are true, the blower will have power.

When you take a voltage reading at the battery, test on both the battery post and the cable clamp. They're not always the same potential. A film of oxide can/will sometimes insulate one.
Also test for voltage on the new cables. e.g. batt + post to starter stud, then batt neg to engine.

You will find an open circuit.

 

[Joshua Nichols]

Re: Hot Start/Electical Problem

Overhauled starter eh??? Had a old Bronco with the same engine.. Use to do the same thing... Drove me nuts... Couldn't restart after warm.. It was such a pain.. I musta put 6 rebuilt starters on.. All would start it cold... Finally bought a new one.. solved all my troubles.. They wasn't replacing the bearing in the nose of the starter during the rebuilds.. Kinda unrelated.. I don't trust rebuilds less I rebuild them...
I would say bad ground with your issue..

 

[haulnazz15]

Re: Hot Start/Electical Problem

I appreciate the feedback, but I'm willing to bet that maybe the battery will show less than 12V when this occurs since the electronics that require 12V cease to operate. So if that's the case, then there is something drawing/shorting or discharging the battery during operation.

 

[wire2]

Re: Hot Start/Electical Problem

I appreciate the feedback, but I'm willing to bet that maybe the battery will show less than 12V when this occurs since the electronics that require 12V cease to operate. So if that's the case, then there is something drawing/shorting or discharging the battery during operation.

When nothing will work after a "heat cycle", there's no current being drawn from the battery, hence the voltage should be up near 12v.

Even IF the battery was down to 6 volts, the blower would still run, just much slower.

Try the tests I suggested, you will find an open circuit.

 

[6meter]

Re: Hot Start/Electical Problem

Even IF the battery was down to 6 volts, the blower would still run, just much slower.

If your blower is wired seperatly then either the ground or pos connection is bad. As said, half a battery will turn a blower motor. Two batteries generally don't go from zero volts to 12 volts by sitting. Wires grounded at the starter, with all that not working tells me there is a problem with the starter motor ground.

 

[HT32BSX115]

Re: Hot Start/Electical Problem

That is why I hate amp meters. Too many connections in too many places and too long a run of wire. All your power has to go from the alternator to the helm and back to the engine to charge anything.
I would be looking at all the connections (especially the main engine harness plug) on the Red and the Red/white wire. If it goes dead when warm, then you loose accessories also.

As usual, Don is "SPOT-ON"!!

Mark Twain used cockpit installed AMMETERS and as such, ALL the current to run everything including the starter solenoid, (except the starter and trim pump) runs all the way to the instrument panel THROUGH the ammeter and then to everything else.

They also used poor quality crimp connectors and standard "BUS" fuses.

Look for poor connections anywhere along that main A+ supply wire from the engine to and from the ammeter, the ammeter, fuse block and ALL the connections and fuses, AND ALL the ground points and crimp connectors under the instrument panel, and at the engine.

I would remove the ammeter and replace it with a volt meter. A volt meter is a FAR better measure of alternator operation anyway.

Cheers,


Rick....

 

[haulnazz15]

Re: Hot Start/Electical Problem

While I wouldn't mind rewiring things, I'm not sure it's quite plug-n-play with a Ford engine. What would be involved in swapping out the ammeter with a voltimeter since it can't just be as simple as a guage swap right? I would assume a new wire would have to be run from the starter solonoid to the ignition key switch.

While MT may have used some less than stellar connections, this is the first electrical issue we've had with the boat in almost 20 years, and likely the first issue ever. So, I can't complain about the workmanship just yet.

The ammeters still work fine in all of the aircraft I fly, but they don't have the 30'+ run of cable up to the helm and back.

 

[mkast]

Re: Hot Start/Electical Problem

A shunt would have to be installed between end of the positive battery cable and the terminal on the solenoid for an amp meter to work.

 

[haulnazz15]

Re: Hot Start/Electical Problem

Well, I have looked up under the dash before, but I wasn't really paying much attention to the wiring going to the gauges themselves since I was looking at the accessory switch panel. I know I can buy newer 9-pin wiring harnesses that end with a trailer-wiring style connector, but that's another project. The guages/trim pump wiring does not seem to be affected by any of this, although I didn't think to try and run raise/lower the drive while this was going on.

 

[HT32BSX115]

Re: Hot Start/Electical Problem

While I wouldn't mind rewiring things, I'm not sure it's quite plug-n-play with a Ford engine. What would be involved in swapping out the ammeter with a voltimeter since it can't just be as simple as a guage swap right? I would assume a new wire would have to be run from the starter solonoid to the ignition key switch.

While MT may have used some less than stellar connections, this is the first electrical issue we've had with the boat in almost 20 years, and likely the first issue ever. So, I can't complain about the workmanship just yet.

The ammeters still work fine in all of the aircraft I fly, but they don't have the 30'+ run of cable up to the helm and back.

You haven't had to replace the floor yet?


In reality, you could remove the ammeter and take the 2 wires that went to it and short them together. Then connect them to the "+" connection of the voltmeter.

That would be the "hard" way though. One of them wouldn't really be required anymore. You could also "short" them together at the other end too.... making them the equivalent of 1 thicker wire. which would be better.

Don't confuse an ammeter with a "LOADMETER" common in aircraft electrical systems.

Loadmeters measure generator/alternator (current) output only. (my Stinson is wired that way....most aircraft are wired that way.....)

That's a good thing too since it tells you if the gen/alt is working too.... but doesn't really tell you what the whole system is drawing (until the battery is fully charged and the engine is off)

Most ammeters in boats (and cars) measure current draw (if the generator is not operating) or charge current if it is running. (they're "Zero-center" ammeters)

A voltmeter is MUCH better since anything above about 12.3 volts or so indicates "charge".......... if the alt/gen is NOT operating the voltage will almost always be 12v or less......

 

[haulnazz15]

Re: Hot Start/Electical Problem

Well I kind of figured the exisiting wire would go to the positive on the voltimeter, however the issue of everything running through the ammeter leads me to believe everything would be running through the voltimeter at that point, which doesn't solve any amperage/fire issues except that when the fire errupted, you'd be able to tell the voltage at the time, lol.

 

[HT32BSX115]

Re: Hot Start/Electical Problem

leads me to believe everything would be running through the voltimeter at that point,

Well, "everything" DOES "run through" your ammeter. In that the meter would necessarily "PEG" if a short occurred "downstream" of the ammeter.....you wouldn't read anything if it occurred "upstream" of it.....

It would not "run through" the voltmeter since the only connections on a voltmeter is "+" and GND. The voltmeter would only read the voltage present at the meter where it was connected .(and it wouldn't really matter where you connected it)

An ammeter is not a fire detector either.

And you shouldn't see a pegged meter either since the fuse would (should) open way before the fire erupted! (you hope)

 

[bruceb58]

Re: Hot Start/Electical Problem

You have no idea if your battery is even charging. Measure the voltage at the battery when the engine is running and when your accessories stop working.

And get rid of the ammeter. You just need to add a new wire from the alrenator to the battery replacing the existing one that runs up to your ammeter.

 

[haulnazz15]

Re: Hot Start/Electical Problem

Lol, yeah I was just joking about the fire issue, I think the last thing on my mind would be to look at the ammeter during an electrical fire. I will dig into it this weekend and post some results. I appreciate all the feedback guys, hopefully I can get this one squared away quick.

 

[tinman4u]

Re: Hot Start/Electical Problem

Post an update when you get her don, I have that issue also. I switch to both battery and she cranks.