Help! Electrics and circuit breaker

[Lauren Child]

I've just tried to wake Dolly the CMP up after the winter and she doesn't want to get up. Battery is freshly charged and had juice to run the fuel pump to prime. Then I hit the starter button and I just got a "click".

I tried a couple of times, checked the engine moved freely with the starting handle, tried again and still just "click".

I'm assuming that's a duff solenoid or starter motor. "Click" I'm assuming is the solenoid moving.

Then, the whole electrical system stopped working. No lights, no fuel pump, no nothing. Dead as a dodo.

So, now that's looking like circuit breaker as well. I've left it a while too cool but still nothing.

Two queries:

• Is the circuit breaker on the board behind the dash or is it somewhere else? (Cab 13, newer dash with round dials). What does it look like?
• Can anyone give me the connections on the solenoid and circuit breaker to test?

Thanks for your help all, I'm still getting to grips with all this.

[Mike K]

hi


First : check that the battery terminals are clean and the lead connections are clean and making good contact . They often gum up after a while, give the terminals a clean .

Sounds like a bad connection somewhere . Give the terminals on the solenoid a clean as well . If that doesnt work, try by-passing the solenoid with a jumper lead across the large lead terminals on the solenoid.

Mike

[Lauren Child]

aha,

I just left her a little longer and got the electrics back, so hopefully that means the circuit breaker is fine and just took a bit longer to cool.

Pushing the starter button again, and the same thing happens. Small noise, then all electrics dead again.

Is the circuit breaker in-line with the starter motor, or is it just for the lights etc.? I'd assumed it was just the lights and low current side.

[Lauren Child]

Originally Posted by Mike Kelly

hi


First : check that the battery terminals are clean and the lead connections are clean and making good contact . They often gum up after a while, give the terminals a clean .

Sounds like a bad connection somewhere . Give the terminals on the solenoid a clean as well . If that doesnt work, try by-passing the solenoid with a jumper lead across the large lead terminals on the solenoid.

Mike

I've given the terminals a good clean, but no joy. Had electrics back fine for lights etc. but everything dead again after pushing the starter button and hearing the click.


Well that's wierd - looking at the circuit diagram in MB-F1 the circuit breaker only operates on the lights.

[Mike K]

Lauren

There isn't a circuit breaker on the starter motor circuit itself . Still sounds like a bad connection somewhere , corrosion on a terminal maybe . The starter motor draws massive amps from the battery , the battery voltage will drop significantly while the starter is turning over .

Try wiggling the solenoid connections e.g., the thick leads on it . You may have to loosen the nuts a bit to wiggle the leads .

Mike

[Richard Farrant]

Hi Lauren,
As Mike says, check battery connections, but also check the connection of the earth lead from battery to chassis, and the earth lead from chassis to engine, these are often overlooked and the biggest sources of problems.

[Alex Blair (RIP)]

Originally Posted by Lauren Child

aha,

I just left her a little longer and got the electrics back, so hopefully that means the circuit breaker is fine and just took a bit longer to cool.

Pushing the starter button again, and the same thing happens. Small noise, then all electrics dead again.

Is the circuit breaker in-line with the starter motor, or is it just for the lights etc.? I'd assumed it was just the lights and low current side.

You have a bad ground some where or every where..Those old electrical systems were 6 Volt and very suseptable to dirty or corroded connections..Once you get all the grounds..motor to frame..frame to cab..cab to dash and all the rest..she should just fly..
unless Keefy was playing with it ...
That would suck..
Good luck..
I usually recommend changing all the old electrical leads with arc welding cable ./.It is braided and very flexible and has hardly no voltage drop.

[Lauren Child]

While tinkering I had the electrics go just with the indicators running (after a good hour of leaving her to cool) so the loose connection sounds like a winner.

Given that the cables are a bit duff in places anyway, I've got some fresh 19mm2 cable waiting to go on when I get a break with the weather. I'll see how she is with that, plus at that stage I can have a good run through the electrics and bypass bits to see if the starter is OK.

Does anyone know where I can come by a spare solenoid / dash rear circuit? I'd ideally like to have them on-hand when playing, just in case.

Ta
Lauren

[Phil Waterman]

Hi Lauren

If Dolly is a Chev and just goes click on a fully charged battery, as said the most likely cause is a bad connection on the battery. But also check the other end of the cable, I have had problems with ground connection as this one is made through the engine mounts from the chassis in many cases, I've added a cable directly to the engine. The other trouble spot on Chevy is the contacts in the starter switch.

If you have a Ford with the remote electric solenoid don't know what to tell you.

Also if as you say, your cables are bit duff by all means replace them with the heaviest cable you can find often called welding cable, I forget the size about 1/2" of fine copper wire. When I make these up I go to the industrial electrical house and buy the length I want along with the lug cable ends I prefer to solder the ends on instead of crimping. Same with the battery ends from an automotive supplier. But do make sure it is well clamped in position and that nothing else is hitting against it to wear through. I all most lost my truck and shop because of a cable fire a couple of years ago.

Now as to the circuit breaker, the original vibrating type are difficult to find. I've gone over to a standard thermal 30 amp truck breaker. Of course this does nothing to protect the hot battery cable. After my experience I've slid a piece of hose over that at critical points.

Cheers Phil