Toasted ground

[Hiccup]

Evening folks,
Anybody know if this toasted ground is from the starter? It's a 77. Noticed smoke when she was having trouble turning over. Thanks

 

[Hiccup]

Hmmm maybe a couple more pics might help.

 

[snaggletto]

Starter grounds to the chassis through its mount, no ground wire. I'm not aware of any reason to have that wire you show attached to your side apron. Where does/did it lead to?

 

[CruiserCoLittleRock]

Evening folks,
Anybody know if this toasted ground is from the starter? It's a 77. Noticed smoke when she was having trouble turning over. Thanks

View attachment 1295298

classic symptom of a poor ground at the starter...in fact, just repaired the exact same wire on a 77 for one of my clients trucks in Texas you should have a large black wire with yellow tracer from the starter to the frame. The starter is looking for any ground to do its job and the amount of amperage fries small wire grounds nearby from the resistance. If you dont have that ground strap, jsut make one and then unbolt and retighten the starter and clean the frame where the strap bolts up with sandpaper or a gasket prep high speed.

 

[snaggletto]

I didn't know about that ground strap. I stand corrected!

 

[KingAir Driver]

I'm trying to remember, thought that was from the three wire alternator plug. Check the wiring diagram. My 40 is 5,000+ miles away so I can't go look.

 

[Hiccup]

Thanks for the tips. Cruiser I have that ground strap and have cleaned it many times......but not in over a year though. Probably what caused the cookout. As for where it comes from I'm not sure. It disappears into a bundle of others wires that are wrapped up tight with electrical tape. You can see it in the second pic. That bundle goes down and splits at the firewall. A black and white wire comes off the starter and enters the bundle there. I'll try and trace it better today and take a pic. I really need to take care of these grounds as per Coolerman and save myself a lot of trouble. Cruiser do you know where that ground comes from?

 

[CruiserCoLittleRock]

the ground in that pic is a supplement to the alternator pigtail i believe, I would replace that whole wire and then add a 12 gauge wire to your alternator positive and kinda redo your pigtail while you are doing the repair....the ground strap on the starter is like a 10 gauge wire with a large eye for the M12 bolt in the starter about a foot long and then a small M8 eyelet for the frame rail. It should not be wrapped up in the harness at all, its a standalone add on.

I would also loosen the starter bolts and retighten and loosen the alternator bracket bolts and retighten just to ensure a good contact.

 

[Hiccup]

Thanks cruiser! I will do that. I was thinking it was from the starter solenoid in this pic. I'll give it a shot. Thanks again.

 

[NCFJ]

What I see when I open the hoods of many rigs is an electrical nightmare. Wires all over the place with no protection at all, grounds rusting away etc. I would venture to say that bad grounds cause well over 50% of electrical issues in our trucks. When I do a swap I always make up all new battery cables 1/0. One to frame, engine and motor. I also run dedicated ground from bat neg to fuel pump and another to the dash.

Putting one of these serrated washers between the ground lug and frame,body,block also helps maintain a good connection

 

[KingAir Driver]

Just looked at the wiring diagram, the white black connects between the E on Alternator plug then continues to the E on the regulator, with a tie in ground point next to the coil. Maybe ohm the wires between the two plugs for continuity. I'd make sure your alternator/regulator are charging after replacing. Hopefully the regulator didn't fry.

The white black off the starter should be going to the coil.

 

[CruiserCoLittleRock]

Just looked at the wiring diagram, the white black connects between the E on Alternator plug then continues to the E on the regulator, with a tie in ground point next to the coil. Maybe ohm the wires between the two plugs for continuity. I'd make sure your alternator/regulator are charging after replacing. Hopefully the regulator didn't fry.

The white black off the starter should be going to the coil.

The White/black wire is the starter wire from the ignition switch, the two wires next to it go back to the coil to prevent a loss of signal during cranking only.

You do have a nice ground strap Op, are your positive cables crimped or soldered, keeps us informed after you repair that ground in the pigtail...Id like to know what you found just for future reference

 

[Coolerman]

You guys are dyslexic!
The color of the wire from the starter to the key switch to engage the starter is BLACK/White. This is a large 14 ga wire. If equipped with it there will be a smaller Black/White (16ga) wire that is the ballast bypass wire back to the + terminal on the coil.
ALL grounds on the FJ40 are WHITE/Black. The ground shown is part of the ground buss system. See hand draw diagram attached for ground Buss.

 

[Hiccup]

I appreciate all the input on this. Being a one banana mechanic it's gonna take me a little to digest this. But I will do it.
This is a relatively new starter. The old one got fried last May 26th (I remember cause it was my wife's bday and we were going fishing. Happened right around the corner from my mechanic and he pushed me into his lot. I felt obligated to let him replace the starter. He also said that my battery was bad at the time. It would still start the truck but my amp meter always seemed to be on the plus side after this. Well I put off getting a new battery until she started really having a hard time turning over. In fact she eventually wouldn't. So that's when I got a new battery but I suspect that this damage was done before while trying to get her to start. I did smell something electrical burning but I thought I was just being hard on the starter. That's when I figured she needed the new battery. I'm assuming that they installed the correct starter and that that was all that was damaged from the original fry. Why would my amp meter be in the plus if all was good. Would a battery that couldn't hold a charge cause this? Thanks again!

 

[sggoat]

What I see when I open the hoods of many rigs is an electrical nightmare. Wires all over the place with no protection at all, grounds rusting away etc. I would venture to say that bad grounds cause well over 50% of electrical issues in our trucks. When I do a swap I always make up all new battery cables 1/0. One to frame, engine and motor. I also run dedicated ground from bat neg to fuel pump and another to the dash.

Putting one of these serrated washers between the ground lug and frame,body,block also helps maintain a good connection

I would up that ground problem estimate to maybe 90% of electrical issues(Just Ask Claudia--)

 

[sggoat]

The White/black wire is the starter wire from the ignition switch, the two wires next to it go back to the coil to prevent a loss of signal during cranking only.

You do have a nice ground strap Op, are your positive cables crimped or soldered, keeps us informed after you repair that ground in the pigtail...Id like to know what you found just for future reference

White with a black stripe is always ground(77)-----unless the wiring has been molested-
The wire from IG to starter is Black with a white stripe, batt to starter soln should be solid black

 

[CruiserCoLittleRock]

You guys are dyslexic!
The color of the wire from the starter to the key switch to engage the starter is BLACK/White. This is a large 14 ga wire. If equipped with it there will be a smaller Black/White (16ga) wire that is the ballast bypass wire back to the + terminal on the coil.
ALL grounds on the FJ40 are WHITE/Black. The ground shown is part of the ground buss system. See hand draw diagram attached for ground Buss.View attachment 1296919

lol ur right my bad, and man it was dyslexia cuz I do wiring for people all over the country and I was just sure I was right as rain...saw the alert on the response and was like ...well damn Im stupid

 

[Hiccup]

Wanted to say thanks for all the help. On further inspection I found this on the E terminal. Guess I know what needs to be replaced. Right after I clean up every other ground I can find. Hopefully my alternator is ok.

 

[Coolerman]

That pic shows a classic problem with the FJ40 wiring system. If the starter or the alternator does not have a good solid ground, they will attempt to pull current through any ground that is good in order to do their job. Usually through the alternator, regulator and ignition grounds. Since these are smaller 14 or 16ga wires they WILL melt.

In addition to the starter ground to frame, and the engine block to frame, make sure the alternator is well grounded to its mating bracket, and the engine. You can use a bonding jumper of say 10 ga between the body of the alternator and the engine block if you don't want to dismount and clean the alternator to mounting brackets to engine. Just I would add that bonding jumper anyway in addition to properly grounding the alternator through its mounting bracket.

You also need the proper 3 pin latching connector for the alternator to attach ground wire and the white/green wire. I sell this connector and new terminals cheap. Part #FLF3P6.3W $2.55 + $3.00 shipping. Send me a PM to order. I also sell the White/Black wire in 14, 16 and 18ga sizes by the foot, just tell me what ga and how many feet you need.

You are going to have to un-tape that harness and see if that melting goes deep into the harness. It may have melted other wires together which will cause no end to your weird problems! If it does appear to have gone deep, and damaged other wires, the proper way to fix it will require pulling the harness off the truck, completely un-taping it, replacing the damaged wires and taping it back up. I also sell the correct non-adhesive harness tape for that job. (I also stock all the proper color striped wires for your truck)

Good luck!

 

[Hiccup]

Coolerman thanks for the to do list! Really appreciate you knowledge and willingness to help. I'm away on family matters for at least a week. Then I'll have a chance to see how much damage was done. You can expect a pm from me then for sure. BTW thanks for posting the wiring diagram for my truck a while back. I carry a printed copy in the truck and a saved copy on my iPad.