Sparks under dash
Moderators: Cal_Gary, T. Highway, Monkey Man, robi
Sparks under dash
Hi guys, I was driving, got sparks under The – and then the whole truck died. I now have no power. Obviously a fuse blew somewhere, but I'd like to find out which wires it could be. Do you think it's the ignition wires? I'm sitting on the side of the freeway so I haven't been able to really troubleshoot.
Re: Sparks under dash
Moto,
When a fuse blows there shouldn't be sparks.....and the fuses reset.....so they don't need to be replaced. If you saw sparks it should be obvious where they were coming from. Probably the insulation on one of the wires went south and made contact with the truck. Look around under the dash by the ignition switch and the gauge cluster for signs of charring (blackness). You can also run your fingers over the wires to feel for broken insulation. For the truck to die I would think it would have to be wiring to the ignition switch, but that's also feeds the gauges.
regards,
bob
When a fuse blows there shouldn't be sparks.....and the fuses reset.....so they don't need to be replaced. If you saw sparks it should be obvious where they were coming from. Probably the insulation on one of the wires went south and made contact with the truck. Look around under the dash by the ignition switch and the gauge cluster for signs of charring (blackness). You can also run your fingers over the wires to feel for broken insulation. For the truck to die I would think it would have to be wiring to the ignition switch, but that's also feeds the gauges.
regards,
bob
Re: Sparks under dash
OK thanks. I figured it's a grounding out wire. I'll retape everything and fix it. The gauges went dead, too. Where is the fuse block?
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Re: Sparks under dash
Motomon,
Taping deteriorated wires is a quick short term fix to get home. It sounds like you should strongly consider a re-wire, I'd have for you to loose the truck to an electrical fire.
Taping deteriorated wires is a quick short term fix to get home. It sounds like you should strongly consider a re-wire, I'd have for you to loose the truck to an electrical fire.
Re: Sparks under dash
Thanks. True, it's a quick fix but I gotta do something since I keep the truck on the street. 72hr parking is generally enforced in these here parts 

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Re: Sparks under dash
Ouch, you live in one of the other Commy states. Good luck.Motomon wrote:72hr parking is generally enforced in these here parts
Re: Sparks under dash
Hi Moto,
There is no fuse block in these trucks, just three circuit breakers located under the dash by the gauges on the bracket that runs from the firewall to the dash and has the handle for the cowl vent. The breakers are mounted on the side of the bracket facing the steering column. One of the 3 wires from the ignition switch runs directly to a breaker, so you can follow that wire ........it should have a number 11 tag on the wire.
regards,
bob
There is no fuse block in these trucks, just three circuit breakers located under the dash by the gauges on the bracket that runs from the firewall to the dash and has the handle for the cowl vent. The breakers are mounted on the side of the bracket facing the steering column. One of the 3 wires from the ignition switch runs directly to a breaker, so you can follow that wire ........it should have a number 11 tag on the wire.
regards,
bob
Re: Sparks under dash
Ok, I found frayed wires. Taped it all up and I have power. Headlights don't turn on and truck won't start. I have two random female plugs. One comes from ignition but I don't see where it would go.
Re: Sparks under dash
Here's what I'm looking at. It's kind of a rats nest. I need to follow more wires. The PO wired up a bunch of speaker wires...perhaps this thing has a 12V alternator that I didn't pay attention to.



Re: Sparks under dash
Lastly - the truck turns over just fine (albeit batteries are getting weaker). Seems I have fuel (electric pump runs), but probably no spark.
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Re: Sparks under dash
Hi Garrett,
That is quite the rats nest of wires. I would definitely disconnect the batteries and do a detailed check of the wiring. It would be a shame to have the truck burn up while its sitting in the parking lot or on the street. Here are two wiring diagrams that CUZ posted a while back.
WO turn signals

B1

Bert
That is quite the rats nest of wires. I would definitely disconnect the batteries and do a detailed check of the wiring. It would be a shame to have the truck burn up while its sitting in the parking lot or on the street. Here are two wiring diagrams that CUZ posted a while back.
WO turn signals
B1
Bert
1952 M37 W/W Rebuild @ 59% complete
Engine rebuild @ 95% complete
1985 M1009, 1990 M101A2, 2008 M116A3 Pioneer tool trailer
MVPA # 24265
NRA Life Member
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Engine rebuild @ 95% complete
1985 M1009, 1990 M101A2, 2008 M116A3 Pioneer tool trailer
MVPA # 24265
NRA Life Member
NRA Cert. Personal Protection Pistol Instructor
NRA Cert. RSO
Class III RSO/KCR
Re: Sparks under dash
I am seeing a lot more exposed copper than I'd be comfortable with
Re: Sparks under dash
Yea, looks like I have a nice weekend of wiring. According to the 'with turn signals' diagram, I think my problem is the #11 wire going to the breaker for the headlights. The lights do not turn on with the battery terminal switched to on. So I'll get the volt/ohm meter out tonight. I always have a fire extinguisher in all trucks for emergencies.
Re: Sparks under dash
Got it fixed! It was the #11 wire. I think the truck even runs better now.
Re: Sparks under dash
Being that I work with electrical items every day,I see way too much exposed copper in your pics. I would pick up some heat shrink tubing to correct the issues you have there. Yes, disconnect your battery( or batteries ) to prevent arcing and shorting.