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Alternator guage on LRT caught fire!

Posted By: chargervert

Alternator guage on LRT caught fire! - 01/22/14 07:21 PM

I have a 78 Little Red Express Truck. The truck has been sitting for ten years. I just replaced the exhaust system,starter,battery cables,and brake calipers. I am trying to get it back on the road this year. After I changed out the plugs and changed the oil,I was trying to tune the carb,when I saw smoke coming from behind the dash. I shut the truck off and disconnected the battery. I had to reach up behind the alternator guage and pull the smoldering insulation out before the truck caught fire. The wires to the guage were red hot. I also noticed one of the wires to the voltage regulator had melted as well. What is the best way to go about fixing this issue? Any help would be greatly appreciated. Thanks Pete.
Posted By: Polarapete

Re: Alternator guage on LRT caught fire! - 01/22/14 07:45 PM

I am surprised with all the older Mopars that you own, that this is the first time you have run in to this issue with the ammeter gauge and wiring. I am not an expert and I am sure that someone with good technical skills will chime in. The basic issue is that you cannot expect a system that was designed when generators and 6 volt systems were good enough to be adequate for modern cars. Running all under dash power through the ammeter is one of many weak links.
Posted By: therocks

Re: Alternator guage on LRT caught fire! - 01/22/14 08:16 PM

Common problem on those years.I had 5 of them and eliminated the amp gauge on all.The gauge starts to melt then shorts.I simply disconnected them and used a small screw and nut to hold them together.Tape real good and install a volt meter.Last truck I had went 6 years like that.Rocky
Posted By: chargervert

Re: Alternator guage on LRT caught fire! - 01/22/14 08:51 PM

I have owned Mopars for 30 years,and I never had this issue. I did buy a car that had a dash fire before,and this was probably the cause. I will connect the wires as you said Rocky. I have a factory guage pod with the voltmeter and vacuum guages. I do not have the wiring for the guage. How would I wire up the voltmeter guage?
Posted By: stumpy

Re: Alternator guage on LRT caught fire! - 01/22/14 08:53 PM

Volt meter is 12v key on and a ground.
Posted By: chargervert

Re: Alternator guage on LRT caught fire! - 01/22/14 09:15 PM

Thanks Stumpy. I will wire it like that. I wondered if using the factory guage could be wired right into the harness. The optional guage pod must have a plug in somewhere on the harness.
Posted By: SomeCarGuy

Re: Alternator guage on LRT caught fire! - 01/22/14 11:07 PM

I just take one lead from the amp gauge and put it on the other terminal. Some hamfist put together the ends on a car I bought with a screw and tape. Ended up arcing under the dash. Not a fun experience.
Posted By: BulletBob

Re: Alternator guage on LRT caught fire! - 01/22/14 11:20 PM

Quote:

Volt meter is 12v key on and a ground.



You can disassemble the original amp gauge & a voltmeter & put the voltmeter on that space using the original face
Posted By: I_bleed_MOPAR

Re: Alternator guage on LRT caught fire! - 01/22/14 11:59 PM

Some good reading here-

http://www.madelectrical.com/electricaltech/amp-gauges.shtml


Did it on my sons Charger and will do it on any other older Mopars I may wind up with, just for the peace of mind.


Tim
Posted By: shanker

Re: Alternator guage on LRT caught fire! - 01/23/14 12:14 AM

Quote:

Quote:

Volt meter is 12v key on and a ground.



You can disassemble the original amp gauge & a voltmeter & put the voltmeter on that space using the original face



I wish I could find a gauge that will mount in the 72-74 dodge truck panel to do that.... got any links?
Posted By: 69HemiGTX

Re: Alternator guage on LRT caught fire! - 01/23/14 10:06 AM

This is the Achilles heel of the 72-80 truck gauges. The way Ma did it, 100% of the battery power is routed through the gauge, making fires quite common. Tim linked to what seems to be the most popular tech article about it and how to fix it.
Posted By: retiredguy

Re: Alternator guage on LRT caught fire! - 01/24/14 02:14 AM

According to the Little Red Express owners club, this is one of two updates that are endorsed by them. The other update is a steering box brace. Here is a link to their web site-http://www.lilreddad.com/.

I also have a LRE and I am doing the same updates. I just took my dash apart and I found the footing for the amp gauge were melted. I am so glad that I checked. Does anyone know a of a volt gauge that will fit into the amp gauge area in the dash.

Larry

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Posted By: therocks

Re: Alternator guage on LRT caught fire! - 01/24/14 02:26 PM

Larry those dont look bad at all.My one would die when I was plowing and loose all power.Pulled the gauge and it was totally melted.Im suprised it didnt burn.It was one of the first ones I had.I installed my volt gauges in the part that goes to the DS of the dash.I wasnt worried about correct looks.I do have a NOS harness at the house for a RC.I dont know if its for the volt meter though.It supposedly is for the dash with all the fancy gauges with tach etc.Rocky
Posted By: NITROUSN

Re: Alternator guage on LRT caught fire! - 01/24/14 02:39 PM

I fixed many ammeters and they will not heat up again. Simple fix.
Posted By: VL21

Re: Alternator guage on LRT caught fire! - 01/24/14 04:41 PM

Important note, I am an electrical idiot ...

Because I am an idiot, I have to ask ...was this problem solved on the '81 and newer trucks?

My '85 moves such a small amount that I am not sure that it is even moving, and previous 88 and 92 trucks as I remember were the same.

I DID have a 72, 74, and 76, and none of them had this problem ... of course that WAS in 73,74, and 76 ...

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Posted By: NITROUSN

Re: Alternator guage on LRT caught fire! - 01/25/14 05:09 AM

Quote:

Important note, I am an electrical idiot ...

Because I am an idiot, I have to ask ...was this problem solved on the '81 and newer trucks?

My '85 moves such a small amount that I am not sure that it is even moving, and previous 88 and 92 trucks as I remember were the same.

I DID have a 72, 74, and 76, and none of them had this problem ... of course that WAS in 73,74, and 76 ...



You do not have the old inductive style. You can remove your cluster and the truck will still work just fine. The newer style uses a shunt style set up and just senses current which makes it operate.
Posted By: VL21

Re: Alternator guage on LRT caught fire! - 01/25/14 07:10 AM

Quote:

Quote:

Important note, I am an electrical idiot ...

Because I am an idiot, I have to ask ...was this problem solved on the '81 and newer trucks?

My '85 moves such a small amount that I am not sure that it is even moving, and previous 88 and 92 trucks as I remember were the same.

I DID have a 72, 74, and 76, and none of them had this problem ... of course that WAS in 73,74, and 76 ...



You do not have the old inductive style. You can remove your cluster and the truck will still work just fine. The newer style uses a shunt style set up and just senses current which makes it operate.



Good to know,I will sleep better tonight. Thanks
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