Smoked a ground wire today

[TardedPanda]

I put a new starter and battery in my truck to try and iron out a starting issue.

 

To start, my truck wouldn't start when warm. It would just click. Put a starter in, and then it clicked continuously while turning the key. Put a new battery in and it started fine the first two pulls. Try to crank the truck and nothing happens, no click, nothing. Keep turning the key and the truck finally cranks. Fine, I'll get to this problem later.

 

Fast forward two weeks and I walk out to work on it and the truck fires on the first bump. I let it warm up and take it for a two mile drive. Come back home and turn off the truck. I crank it two more times no problem then my problem arises. Turning the key nothing happens. Keep turning and then it slow crank. I let it slow spin for maybe five seconds and I notice smoke from the hood. Then I smell it. Anyone who has burnt a wire knows this smell. I let the smoke out of the ground wire that runs from the valve cover to the firewall.

 

I cleaned all the grounds last year when I brought the truck back to life. I'm at a loss at the moment. Any type of direction would be awesome.

 

Sorry for the long post and any typos. I know we at ratsun like pictures so I will post one once my laptop is charged. I hate that I love this little truck so much. Lol.

[datzenmike]

The starter should ground return from the intake to the battery negative. On the L series it's the head to the negative battery terminal.

 

720s had a dedicated ground wire from the battery negative to the body beside the battery.Your starter is trying to ground return through this wire by going from the valve cover to the firewall. It should be through the large black cable from the intake. Probably corroded or loose or maybe missing?

[TardedPanda]

You're right, it's on the head, back driver side. You're the King Rat so you already knew that. Lol. It's a Z22 motor.

[TardedPanda]

[datzenmike]

That's not the correct ground wire. Follow the big thick cable from the battery negative terminal.... it should go to the intake manifold on the Z engine I believe. Near the thermostat.

[TardedPanda]

Yeah. I know that one but its not the one that's smoked. I went to take it off (wire from negative post to the head) and I rounded the bolt right under the thermostat so I threw my tools under the hood, slammed it shut, and started drinking. I'm so mature.

 

I know what wire you're talking about though. I cleaned that wire last year. I know the cable is tight on the battery post. I'll try and get it off once I get that bolt out and check it for corrosion. It was my first thought, this forum is full of awesome participants that could confirm I'm heading in the right direction.

 

When that wire smoked, I had a feeling that ground cable from the battery has probably been my problem all along.

[datzenmike]

The small one from the cover to the firewall would not have burned if the proper one on the intake were doinng it's job.

[TardedPanda]

I agree 100%.

[Wagmandu]

I had the same issue with my 81 720, i have owned it since 1997 so been thru alot of issues with it! This one had me stumped for quite sime time but turns out to be an easy fix.  I bought a longer grounding cable slightly longer than the positive one that goes to the starter.  I attached the grounding bolt to the top bolt on the starter that attaches it to the transmission.  Make new grounding cables with slightly bigger wires that connect batt to engine batt to body & body to engine.  Problem solved for the ast 5 yrs!

[Wagmandu]

Looked at it i actually bolted it to the lower bolt, so it wouldnt be so close to the positive wire. Sometimes it will do the same thing for me still, but this just means the battery cables need to be sanded a bit to get a good connection to the battery, usually after it sits for the winter.  Hope this helps!

[TardedPanda]

I replaced the negative ground cable from the battery bc the terminal was loose and wouldnt tighten to the post. I figured that was what caused the secondary ground to smoke, loose terminal didnt supply enough ground resistance. Put a new one on and I still have a starting issue. Alternator only puts out 13.06 volts at idle but puts out more upon acceleration. Battery seems to always be low too. Im wondering if I have more electrical problems. Probably going to replace the positive wire next and see where it goes from there. After that its a draw test to see if the battery is being drained and that's my slow start issue as well.

 

After I fix one thing on Ethol, something else breaks. Lol.

[Wagmandu]

What i did tho was where the ground connects to the engine instead of it attaching to the intake manifold attach it directly to the starter, so both the red and the black large cables end up on the starter, that will solve the starting while hot problem because the path is direct to the battery instead of going thru the engine & the thin lines.  My truck all the original ground wires were rotted out so i had to replace them all.

[Wagmandu]

Good luck tho! finally have mine back on the road after years of fixing stuff!   http://www.rockauto.com  and 

http://www.nissanpartszone.com/1981-nissan-720-pickup-parts.html have been my good friends.  I just picked up a starter for $30 and an alternator for $20!