This one might be interesting!

I was working yesterday delivering fast food. I signed into my delivery app and hooked up my phone to the charger because it was low (Plugs into cigarette lighter) and was putting gas in my car. once done with gas, hopped back in car and the charger is dead and couldn't start car.

There were no lights, no accessories, no nothing. and my phone was very sluggish and kind of locked up.

I took a look at my main fuse 30A that I added to the power going into the car (going to ignition switch).
Years back I bypassed the amp meter and installed 8 gauge wire from alt. to bat. (with 2 ea. 50A circuit breakers - 1 @ alt. bat.+ and 1 before starter relay bat. terminal). The 30A fuse was good, but I changed it anyway cause I couldn't test it at the station.

Next I looked at the circuit breaker and jumped it by connecting the 2 wires together and the car started right up and all was fine. So I thought the circuit breaker died and got 2 new ones. I installed both and all was good and off to work I went.

Now, I started having all kinds of problems with the delivery app and my phone for about an hour and a half. So I started to get pissed and called the support office and these idiots continued to make everything worse. All the while the phone was charging and I was running the car non-stop. So, I stop the car cause this is going to take awhile and continue with the support idiots. I get nowhere, and so I'm calling it a day, I start the car and nothing again...I can't find the problem, my phone locks up, I run my anti-virus program and then try the car one more time and it startes right up and no problem. I head home.

This morning I test everything. The car starts up fine repeatedly. Battery 12.67v before starting, charging cold 14.36v, charging warm 13.75v, inside gauge warm reads 13.5v (normal, high resistanc in wire going from fire wall connection to starter to inside fuse block, gauge connects here).

Idle fluctuates .5 rpm while charging @ 13.88v, turn off car 2 mins.and back on and it's gone (this was a first also). I'm not sure if its related.

Now I'm scratching my head.

Thanks for any thoughts, 74

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Here’s an update since that episode.

I made a mistake in thinking that I had the cigarette lighter on the main fuse for the ign. switch (old brain) , it’s not it’s going to the main 50 amp cir. breaker that the battery bus cir. connects to at the starter relay. So I think it tripped the breaker, but it seemed like a long time for it to be tripped, anyway. (What thru me was thinking the 30 amp fuse should have blown first).

The other thing I found out after digging some more is that the shifter linkage bushing broke (I thought something felt a little funny that day) and the tranny linkage was wobbling in and out of park and reverse. Turning on and off the neutral safety switch on the same circuit, so I replaced that. So I checked the wiring on the transmission circuit and it was bad (connectors and wires, high resistance, looked like coat hangers) at the transmission jumper section. So I replaced all that.

Also the lights source their power from that same 14 ga wire connecting to the relay and I know I forgot to turn them off when I was filling the tank. Oh, I had the lights on, mobil phone charging, neutral safety switch turning on and off all at the same time, and the bad wiring. I’m not sure, but I think that might be enough to cause this problem.

Nothing has happened since, but then again, I haven’t left all this on when the car is off either. And the idle problem is gone too.

I think the light circuit project is coming up on the project list soon.

74

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Where ever you go there you are!

I don't know about your specific year and model (not sure when transmission controls changed from rods to cables, for instance), but in my experience, sometimes weird, jumpy, intermittent electrical problems, especially if combined with gear changes ("It stalls when I shift into Reverse."), direction changes ("The headlights flicker when I make a hard right.'), or bumps, are often caused by the loss of the engine ground connection (woven strap from block to firewall, or heavy wire from Negative battery terminal to body), which causes all of the electrical load from the body to have to travel through the (moving, bouncing) transmission linkage, with varying degrees of success under different conditions.

Do you have a solid connection between the battery ground and the body? The big, heavy ground wire connects the battery to the block, and the starter wouldn't crank without it, but there needs to be a connection to the body somewhere as well.

- Eric

Sorry it took so long to respond to your post MD, been insanely busy.

You know your right about the importance of the grounds. I was reading the other day that they should be the first thing to check. And one of the first things I did with the electrical system was to go over all the grounds and make sure they were clean, tight, and the voltage drop was in specs.

But this article brought up something I wasn't aware of, and that was about the amount of current that can pass thru a body panel ground stud at the same time can get blocked up during times of high demand, low idle, and high temps.

So if youv'e got add ons like electric fan, fuel pump, lights etc. they need to come from different spots not all on 1 post and then 1 wire going to battery ground. Now I fell into this too and I've got my body ground at the lights also handling my electric fan and controler and I think something else. It's all going to the battery grd. terminal on I think a 12 gauge wire that came with the main one which I got from a box store (convenient).

I'm thinking of adding another seperate body ground in a different location with another grd. wire (for the electric fan) also going to the battery. Becuse right now I'm experiencing low fan/no fan overheating problems during idle on hot days. And i'm willing to bet I'm losing current at groud to some degree at that time.

Thanks for puttting that back on my radar,
74

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Glad to help what little I can, '74.

The only thing I would add is that if I had high-demand devices, such as a fan, I would wire their grounds directly back to he battery, or to a repurposed modern car terminal block, the same way you wire their supply directly through relays.

- Eric

Yes, any high load devices should have grounds directly back to a substantial piece of metal on the body (including dash frame), and then you need a ground strap from the body to the battery negative terminal. Usually, people run a main ground from batt to engine block or trans bellhousing/case, then a ground strap from body to engine. You probably know this, but just reiterating.

Slant on,
Lou

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My thoughts on grounds. Heavy gauge (min 4 ga) from batt to block. Braided cable from block to firewall. 8-10 gauge (depending on alt rating) from alternator case to batt. 10 ga from batt to radiator support (if battery in front). Might be overkill but I have a high output alt, and a lot of electricals, and connections can corrode over time.
On my race car, I have a ground tie post inside the car, that goes directly to the battery. I use that rather than trusting sheet metal grounds.

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