Wiring burned up, replaced and won't start

[College Cummins]

Alrite fellas,



Truck died on me the other day, pull to the side, pop the hood, look at the hack job wiring the previous owner did. Burned. Ok, replace it, same way he had it done til I figure out whats goin on. Truck died on me again, this time won't restart. Notice smoke from under the hood crap!#@$%! Ok, get it towed back to the house and hop on TDR. Check fusible links, one down, replaced, another down, replaced. The other, now I realize what the hack job was, by passing the link. Ok, bypassed with a 30 amp in line fuse. The dark blue start/run wire had burned from the bulkhead connector all the way to the engine harness, explitive#@$%!. and then into the engine harness, another explitive. I had an extra engine harness from a 2wd sitting in the garage, put that in. Rewire the start run wire, redo hack job as stated before with a 30 amp inline fuse. All fusible links check out ok. Have power at every spot on fuse block. everything works, radio, blower motor, windows, locks, all lights, etc. Only thing is it wont crank. Run/start wire has power when the key is in the start position. The truck will start if arched across the starter, and will sit there and run like a champ, and nothing burns up. All wires running to the ignition have power and look good, you can tell they've gotten hot b4, but aren't burnt and like I said, check out good. Luckily I have my overvalved truck to run around in.



So, first gen minds, come together and fix my problem please. Ignition cylinder? Truck has 320k+, the odometer stopped at 320k, so...



Thanks,



James

 

[JGrefenstette]

what year and model is you truck? cant tell from your sig. sounds like your talking about a 1st gen cummins, but i dont see one on the list?



have you traced the current from the batt, to the ingnition switch, to the starter, with the key in start position so see where ther break is?

 

[College Cummins]

I have tried to trace where the break is with no success, all seems to have power. Just replaced the starter and auto fuel shut off relays as well

 

[College Cummins]

I'm gonna steal your avatar too if you don't mind

 

[hcole]

Alrite fellas,



Truck died on me the other day, pull to the side, pop the hood, look at the hack job wiring the previous owner did. Burned. Ok, replace it, same way he had it done til I figure out whats goin on. Truck died on me again, this time won't restart. Notice smoke from under the hood crap!#@$%! Ok, get it towed back to the house and hop on TDR. Check fusible links, one down, replaced, another down, replaced. The other, now I realize what the hack job was, by passing the link. Ok, bypassed with a 30 amp in line fuse. The dark blue start/run wire had burned from the bulkhead connector all the way to the engine harness, explitive#@$%!. and then into the engine harness, another explitive. I had an extra engine harness from a 2wd sitting in the garage, put that in. Rewire the start run wire, redo hack job as stated before with a 30 amp inline fuse. All fusible links check out ok. Have power at every spot on fuse block. everything works, radio, blower motor, windows, locks, all lights, etc. Only thing is it wont crank. Run/start wire has power when the key is in the start position. The truck will start if arched across the starter, and will sit there and run like a champ, and nothing burns up. All wires running to the ignition have power and look good, you can tell they've gotten hot b4, but aren't burnt and like I said, check out good. Luckily I have my overvalved truck to run around in.



So, first gen minds, come together and fix my problem please. Ignition cylinder? Truck has 320k+, the odometer stopped at 320k, so...



Thanks,



James

check this. The fuel shut off solenoid is on the back of the injector pump. IIRC it takes a full voltage to pull it up and a partial voltage to hold it up. Maybe you're not getting any voltage to the solenoid in the start position but if you turn the switch on and jump the starter there is enough voltage to pull it in and it will run. I think there is a resistor in series with the solenoid in the run position and straight 12 volts in the start position. I used to have a 91. 5 and had a similar problem.

 

[JGrefenstette]

wow. man i had to take a big double take on that one. i looked and looked again then went back and klicked on the thread again, i was like, what in the heck is going on here. then i scrolled down.



eh. have at it. whats your name again? you may have said it in the past but i cant remeber.

 

[PToombs]

The truck won't start, or won't turn over? Big difference there. You weren't too clear on that.

The solenoid takes full voltage all the time.

 

[College Cummins]

Name is James Williams, and thanks for the avatar.



The truck won't start or turn over. I turn the key to the start position and get nothing. No click, no bump, no nothing.

 

[Simplysmn]

Try jumping the wire going to starter it might be your switch ? or netural safty switch ?

 

[College Cummins]

Here's my logic for it not being the saftey switch. If you put it in netrual, and try to crank it over, it has the same symptoms. I haven't stated that I had tried this already, and thanks for the idea. If that is incorrect someone please set me straight.



And how would I go about jumping the wire goin to the starter?



Thanks,



James

 

[Diesel Nut]

I just went through something similar on my 91. 5. Shut off solenoid shorted out andwas grounding out the whole system. I didn't burn up any wires thankfully. My guess is that if you pull down the steering column covers, and unplug the ignition switch, you can use a multi meter with the continuity tester to check it out. My guess is the start contact in the switch is burnt up and not connecting, thus keeping you from running the starter.

 

[JGrefenstette]

your welcom for the avatar.



as for jumpin the starter. its just like jumping from the battery, but your bypassing all the electrical crap that gets between your battery and the starter. put your ground were ever you want really, then put the positive on the post on the side of the starter. just follow the positive cable that comes of the battery positive terminal. real easy to see on these trucks.



now if you are getting current to the starter and its still not giving you anything. have somebody turn the key to the start position, and then you get under there with a hammer and lightly tap on the starter.

 

[College Cummins]

isn't that just like taking a screwdriver and touching the two terminals on the starter to get the truck to start? I'm just a young pup, bear with me fellas



James

 

[dpuckett]

Have you checked your starter relay? If the rest of the wiring was burnt, it could have taken out the relay.



There is a plug in near the battery with a pink and a brown (14-ish ga) wire. Unplug it, and jump the two wires (on the starter end) to engage the starter.



hcole- nice offer of help and ideas, but wrong type 12v engine. This is a solenoid that is inside the injector pump.



Daniel

 

[College Cummins]

I replaced the starter relay, and the auto shut down relay. Apparently, they come as a package deal now.



James

 

[PToombs]

Okaaaaayyy, but did it fix it?

 

[College Cummins]

Negative, didn't fix it. Now i don't have anything, I've just gotta go thru the whole thing and check each spot I imagine, it was running there for a bit, but I think another fusible link burned up or something. Thanks ya'll, I've just gotta keep pluggin away at it.



James [><]

 

[AVerHage]

you have changed starters since you replaced the wires, I think I'm tracking that, other wise if you haven't it sounds like a starter solenoid issue if you're arching the posts to start it, if you have a new starter already, I'm lost after all the other advice you've been given

 

[Moab4x4]

Short by pump?

I shorted my blue wire at the engine one day at the injection pump. Factory has a cap over the full fuel screw down by the fuel solenoid. I pulled the cap to do some tweaking but didn't notice that the little retaining washer had a tab on it that can rotate and contact the fuel shutoff solenoid. I smoked a fusible link that way.





When troubleshooting starting wiring:

1. When IGN switch is on, but not in the start position, do you have 12V at the fuel shutoff solenoid? (this can be jumped to hot in a pinch to get running. )

2. Start relay. This is the little black boxy relay on the inner fender. This can be replaced with a standard cheap automotive relay from any parts house. This one is tricky. One wire is hot all the time. The switched one goes to the starter. IIRC they are larger guage but it's been a while since I have been in there. The control coil is hot on one side only when when the key is at START AND the clutch switch is closed. (on autos there is a little yellow jumper a couple of inched long plugged into the clutch switch spot on the harness. The control coil is grounded on the other side only when the neutral safety switch is active and working on autos.



I like this little relay as you can really troubleshoot lots of start circuit issues here.

If the key switch is dead, the appropriate wire never gets hot.

If the truck thinks it is not in neutral for autos, both sides of the control coil go hot when in START. You can also test for ground on the harness when in neutral.

You can pull the relay and use a piece of wire with two 1/4 male spade connectors to hotwire the truck from BAT to the starter solenoid wire. (kinda like Daniel's method above).



If the problem is electrical these two areas should point you in the right direction. Do you have a FSM? I have many a smudge in chapter 8 IIRC.

Ken

 

[mmopar]

hi pull covers off around key switch mainwires melt there ac fan blower feeds from that point mike