Ignition system electrical issue

MRWood

Well-Known Member
I was having issues with my ignition system last summer. Motor is a 92 4.3L v6 Volvo penta. At times the motor would not turn over, no click just dead. It seemed to happen more often on cooler dewey mornings. I would have to mess with the wiring in and around the relay switch and then it would eventually work and fire up no problem. I changed the relay switch a few times but it was still showing up now and again. I’m thinking maybe I may need to get rewired but not sure. Any advice is greatly appreciated. Here is a pic of the ignition diagram from my manual.

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I was having issues with my ignition system last summer. Motor is a 92 4.3L v6 Volvo penta. At times the motor would not turn over, no click just dead. It seemed to happen more often on cooler Dewey mornings. I would have to mess with the wiring in and around the relay switch and then it would work. I changed the relay switch a few times but it still showed up. I’m thinking maybe I may need to get rewired but not sure. Any advice is greatly appreciated. Here is a pic of the ignition diagram from my manual.

View attachment 90340
Bad ground, clean up all your - . Clean free of all corosion. All of them
 
Starter solenoid? I had a similar issue last summer. That was it for me, might be worth a check. Good luck.
 
Starter solenoid? I had a similar issue last summer. That was it for me, might be worth a check. Good luck.
Starter usually you get the click click with no turnover, but worth the look. In my experience lol, lots of pain working on inboards( I am not a mechanic ) 90% of the time was bad ground
 
Starter solenoid? I had a similar issue last summer. That was it for me, might be worth a check. Good luck.
I’ve changed the relay and it doesn’t seem to be the issue unless it’s the wires leading into the relay. Brutus tells me check all my grounds/negative wires.
 
Start with the grounds. Then pull on all the wires in your diagram. give em all a good tug. I was out with a buddy one time at Swiftshire and he had a similar problem. one of the wires on the starter wasn't properly crimped and pulled right out. inside it was so badly burnt that it wasn't making a connection. But you couldn't see it by just looking at the wires.
 
If you are running petronix make sure the plate in the distributor is fully screwed down and grounded that one can cause intermittent ignition issues just from being a tiny bit loose
 
If you are running petronix make sure the plate in the distributor is fully screwed down and grounded that one can cause intermittent ignition issues just from being a tiny bit loose
Thanks Steeler, no petronix plus. When it's acting up the system is dead, no power to the starter.
 
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Grounds, grounds, grounds. All too often, it’s a bad ground. You cannot make sure a wire/connection is good by looking at it. They can look bad and be bad, but they can look good and be bad too. If you wiggled and jiggled the starter relay, I’m assuming under the dash, and it fires up, it’s probably not an issue with the starter or starter solenoid. If your starter relay is in with the motor, then I’d focus my efforts on the wires there.

Make sure you battery switch is OFF

First question, are ALL your other electronics working perfectly? I mean, is there even one other thing that’s been wonky? If yes, start at your battery and work forward. Remove wires from battery, clean, feel for stiffness/brittleness. That’s bad. Any green/black junk on the leads? That’s a sign of corrosion too. Then move to your battery switch. Remove the switch. Remove the leads behind the switch, one at a time. Feel and look for corrosion. Clean each one and reconnect.

If ALL you other electronics are great, then I’d start under the dash. Remove, inspect, clean the grounds. Then follow the positives and remove and clean. That includes the fuse holder, as mentioned above. Also the ignition switch. A bit of corrosion or poor connection is a great way to get intermittent issues.

If you think you have corrosion in a wire, use a multimeter to test for resistance. It’s the ohm thingy. Connect one probe to one end of a wire and the other probe to the other end of the same wire. Do this on a 6-10’ piece of good wire and you’ll see what normal resistance is. If a y of the wires under your dash, at the battery, etc show high resistance, you likely have corrosion.

If you do that, anyone of which is very technical, and there’s still an issue, then you might have a problem with a mechanical component.

My money is on a bad ground.
 
Grounds, grounds, grounds. All too often, it’s a bad ground. You cannot make sure a wire/connection is good by looking at it. They can look bad and be bad, but they can look good and be bad too. If you wiggled and jiggled the starter relay, I’m assuming under the dash, and it fires up, it’s probably not an issue with the starter or starter solenoid. If your starter relay is in with the motor, then I’d focus my efforts on the wires there.

Make sure you battery switch is OFF

First question, are ALL your other electronics working perfectly? I mean, is there even one other thing that’s been wonky? If yes, start at your battery and work forward. Remove wires from battery, clean, feel for stiffness/brittleness. That’s bad. Any green/black junk on the leads? That’s a sign of corrosion too. Then move to your battery switch. Remove the switch. Remove the leads behind the switch, one at a time. Feel and look for corrosion. Clean each one and reconnect.

If ALL you other electronics are great, then I’d start under the dash. Remove, inspect, clean the grounds. Then follow the positives and remove and clean. That includes the fuse holder, as mentioned above. Also the ignition switch. A bit of corrosion or poor connection is a great way to get intermittent issues.

If you think you have corrosion in a wire, use a multimeter to test for resistance. It’s the ohm thingy. Connect one probe to one end of a wire and the other probe to the other end of the same wire. Do this on a 6-10’ piece of good wire and you’ll see what normal resistance is. If a y of the wires under your dash, at the battery, etc show high resistance, you likely have corrosion.

If you do that, anyone of which is very technical, and there’s still an issue, then you might have a problem with a mechanical component.

My money is on a bad ground.
Thank you for the great info.
My starter relay is in with the engine.
Electronics etc are all working perfectly, nothing wonky electrically other than my intermittent starting issue.
The boat has been sitting in it's shed all winterized so I'll now have to go try and start it up, likely over the weekend.
 
Here are a couple pics.
First pic is relay switch and wiring and where I think the issue lies.
Batteries are all good.
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First off those batteries should not sit in parallel when not in use.

Don't be a wing nut and loose those wing nuts

Crank position from key switch should send 12v to that yellow wire on those relays. Check that first after fixing those batteries nuts.
 
First off those batteries should not sit in parallel when not in use.

Don't be a wing nut and loose those wing nuts

Crank position from key switch should send 12v to that yellow wire on those relays. Check that first after fixing those batteries nuts.
Thank you.
Quick question, what can happen if the batteries are left sitting, hooked up in parallel.
Do you not like the wing nuts because they may loosen up?
Why is there 2 yellow wires going into the relay?
 
No wing nuts on batteries
Check 12v at soleniod coming from key switch, Yellow wire
Check neutral safety in control
Key switch
Engine harness plug

In that order

This is the best advice on here. FYI I had exact same issue. Was a simple ground wire ring terminal that was just loose. Exact same scenario.
 
Thank you.
Quick question, what can happen if the batteries are left sitting, hooked up in parallel.
Do you not like the wing nuts because they may loosen up?
Why is there 2 yellow wires going into the relay?
Wing nuts cannot tighten up well enough to ensure a proper connection. In newer engines with ECUs it can actually blow electronic components within the ECUs. Charging curcuits really don't like that. Rectifiers can blow So it's an industry nono. Older engines like yours it will just create intermittent problems such as the one your experiencing. Tight connections.

Batteries don't like sitting in parallel because of the internal impedance. If they are identical then it's sort of OK. One battery will eventually draw the other battery's internal impedance down. Will result in bad battery life.
 
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