Starting issue (strange symptom)

[jrs151]

I get a starter solenoid chattering, followed by complete dead power??? Then waiting a minute, power is available again. Even things that are supposedly directly connected (such as trim motors) have no power at all. I cycle the battery switch to the 2nd bat, to both, to off, back on, still nothing, as seems waiting a few minutes power eventually comes back. Question, can a bad starter or battery switch be "ground out" the entire electrical system - monetarily??

Quick history:
I started noticing the starter solenoid chattering during the initial start. I would get it to turn over eventually, after words, would start normally rest of the day. Seems to only happen after sitting after a few weeks. Classic symptom of a weak or bad battery, resistance at a connection point.? That's what I thought... So prior to any starting attempt I cleaned and fully charged both batteries, replaced to ground cables, made sure all connection points are cleaned (shiny), even replaced the ground terminal on the engine block. I was fully confident that this would have "solved" any weak amps getting to the starter. I was wrong, 1st attempt was the classic machine-gun sound of the solenoid chattering followed by nothing, no power, every thing dead. I thought I blew something, but no sooner than I scratch my head and looked around the engine I noticed my gauges were back on. So I tried to start again, followed by the same thing - chatter, total power failure, then power came back mysteriously. Anybody heard of a symptom like this?

John R

 

[Haut Medoc]

Re: Starting issue (strange symptom)

Well, you dont say what make/model/year, but what is the condition of the wiring harness where the two large plugs meet?.....
Pull it apart & check for oxidization, moisture, tightness....​

 

[jrs151]

Re: Starting issue (strange symptom)

I have a 1992 Merc v8 5.0L with an Alpha 1 Gen II I/O.

Hummmm..... the two large plugs?? I have two batteries grounding to tha same ground terminal on the engine block. The positives of each battery goes straight to the Battery switch (off,1,2,both). The nuetral cable from the switch goes to the starter (solenoid). Console gauges power is on the nuertal terminal of the switch, while trim system is on battery 1 terminal (aka direct connect to bat).

What I find most odd about this problem is that everything goes dead (for a while) after I hold the key to the start position allowing the soleniod to chatter for more than 2 seconds. Could it be the battery switch? But then that doesn't explain why trim power was dead too.

By the way, while trying over and over the boat finally started, so I cannot troubleshoot it anymore since it will now start every time...

 

[Haut Medoc]

Re: Starting issue (strange symptom)

I'm talking about the plug where the engine wiring harness meets the harness that goes to the helm.....
Pull that plug apart & inspect it.....​

 

[jrs151]

Re: Starting issue (strange symptom)

Thanks Haut Medoc, great tip! It didn't fix the problem but you got me looking in the right direction at least. It seems there is not enough power available at the ignition switch to keep the solenoid energized. This is resulting in a type of feed-back loop which causes the solenoid to cycle on/off repeatedly. Ignition switch is fine because jumpering the rear terminals doesn't help. However, I jumpered a 2nd hot wire from the battery directly to the ignition switch to supply additional power and that solved the chattering.

So I'm guessing there must be some type of thermal circuit breaker because it will only chatter for a minute before it looses power to the whole ignition system for a while, then something "resets". Any ideas what I should be looking for?

 

[peacekeeper6]

Re: Starting issue (strange symptom)

see if there is resistance in that wire that is supposed to supply power. One time i had a smached wire holding on by a few threads, just soldered it back together and it solved my problem.

 

[Don S]

Re: Starting issue (strange symptom)

Are all (pos and neg) your battery cables clean, tight and in good shape?
Thumb tight wing nuts is not tight, especially on rusty corroded terminals.

 

[Nova II 260]

Re: Starting issue (strange symptom)

Are all (pos and neg) your battery cables clean, tight and in good shape? Thumb tight wing nuts is not tight, especially on rusty corroded terminals.

Right on. That's what I was thinking. Loose or corroded Batt. cable or terminal connections. Take the Terminals loose and clean them.

 

[jrs151]

Re: Starting issue (strange symptom)

Thanks for the comments but I already did those things as mentioned in my 1st post i.e. "made sure all connection points are cleaned...etc...".

I think Haut Medoc is right on topic with the issue being in the secondary ignition circuit. To prove this I jumpered an extra +12v small wire to the "hot side" of the ignition switch directly from the battery, turned the key to start and guess what - no chattering, it cranked the engine just fine and strong too. Removed the jumper wire and chattering is back, then dies (loss of 12v on the ignition switch) for minute or more. So I think this test proves the following are good: starter, solenoid, batteries, battery cables and terminal conections.

I believe the chattering is simply an feedback from the ignition switch loosing +12 volts at the helm momentaraly, which then deenergizes the solenoid before the starter has a chance to even turn. This cycle repeats itself very fast producing a chattering sound from the engine compartment. If held to chatter too long the whole helm losses power for a short durration.

My guess is that a circuit protection device (thermal breaker) which supplies the helm power is responsible, but I have yet to trace where it might be?? But I was just thinking could the main battery selector switch still be the problem? Power goes from the selected battery, thru the bat sel switch, to the engine which powers the harness which powers the helm. In other words, cranking amps and amps to power the helm both pass thru the sel switch contacts. So if the starter "steals" more power than can pass thru the switches contacts then the harness could experience a significant voltage drop enough to deenergize the soleniod.... hummm...

 

[wire2]

Re: Starting issue (strange symptom)

Open the battery switch. Condensation will start corrosion in there, which will be very obvious if that's the cause.

 

[jcox7483]

Re: Starting issue (strange symptom)

I imagine you've already checked your connections but I had this exact problem and found that the bolt that attaches my starter to the battery cable had melted during a brief short circuit and nobody noticed. May help but like I said, sounds like you've checked your connections.