65fury

gosh dang, got the truck running again after the trubo blew and know this, i had my truck idleing for about 7 minutes this mornig and i get in to go to work, so i flip on the lights and defroster and within 10 seconds there is smoke pouring out from behind my dash , looks like on wire got so hot it burned of all its insulation, a good two feet of wire that is, and melted a bunch around it , i think it is the wire that come off the light switch. does any one have any ideas as to why this would happen, and can i buy a new harness from some where?? thanks



from a very angry jason

loch

I think painless makes a harness.

woodrat

I went through two light switches in a row, because it had been overheated by all the running and trailer lighting running though it. The PO had changed it out once, but the wiring connector for the running lights was all overheated and weak.

When i replaced the switch with a new one, I cleaned up the wiring as best as I could, but didn't redo and I burned up another one almost right away. Ended up splicing a whole new end onto that wire and so far problem solved. Need to switch to LED running lights one of these days.

BearKiller

The factory light switch is barely capable to carry the few lights that came standard on the truck.

Never expect the headlight switch to carry auxilliary marker-lights and/or trailer lights.

Run a big dedicated hot through a BIG toggle-switch, then on to the auxilliary marker-lights.

Run a second big dedicated wire through a second BIG toggle-switch that feeds the TM terminal on the trailer plug(TM=trailer markers).

You want a toggle-switch that sounds like pulling the hammer back on a .45, not some wimpy little rocker that came in a cheap light set.

This will eliminate about 90% of melt-downs.

JimmieD

No disagreement with the above, but in some circumstances a grounded short can cause that problem too. Be good to check it out anyway.

Jim Lane

Would it be too much for the manufacture to use Teflon wire? At least if it burns it won't destroy the entire wiring harness.

I have all of my lighting switched by relays.

My headlights are switched with 4) 30 amp Bosch relays and my tail/ marker lights are switched by a single 30 amp relay. The headlamp switch then triggers all of the relays.
There is also a normally closed spring return DPDT switch in the trigger lead to the tail/ marker relay that when depressed DOWN will flash all of my rear and cab lights (ICC Flash) or if it is turned UP it will blackout all of the running lights. {Sometimes I don't want to be seen}
All of my gauges are also switched on the tail/ marker relay and NOT on the instrument panel dimmer.

The extra 194 lamps are just enough to cause the dimmer rheostat to run hot.
I have not had the opportunity to open up one of our headlight switches to verify this BUT they usually have a thermal breaker inside the housing that will get weak after repeated tripping and cause ALL of the lights to go out on the truck.
I had a 70 Mach-1 Mustang that had almost every gauge Stewart Warner made in it, long story short anyway I was driving down PCH @85 MPH one night and ALL of my lights went out including my headlights which were 150 watt Grant Flamethrowers.
It was instantly pitch BLACK.. I had to rewire the light circuit with what I had in the car so I could get home. My Gyver has nothing on me..
This was back in 1970

I also installed a 70 amp Bosch relay to the ignition switch to then switch on the IGN section of my fuse panel so no load goes through the ignition switch.
I also get full battery voltage at the fuse panel with no voltage drop.

I have noticed that last time I have had my Autometer gauges out that the plastic housing was starting to melt from the heat of the bulb so those will be replaced with LED’s soon.

Hard to believe as expensive as these are that they are not metal or brass like all of my Stewart Warner have been for the last 40 or so years.
Jim

BearKiller

I often recall the night, back in the early eighties, that I came upon a couple of redneck boys in an old beat-up Camaro that had lost it's lights, way out on a long lonely stretch of road, miles from anywhere.

Having nothing whatsoever to work with, except for a pocket-knife, they cut a length of wire from something that they could get by without.

Straight from the battery, to the high-beam side of the nearest headlight, and, by the current backfeeding through the circuit, every light on the car came on.

I have never had cause to use that trick; but, I will never forget it.




I am not going to argue the accuracy of Autometer gauges, as I am sure they are fine; but, their main selling point is variety and COOL looks.

In my book, Stewart Warner always was, and still is, the dependability gauge of choice.

They are kind of plain jane in appearance, with no frills, and poor lighting, but built to stand the racket.

farmer0_1

i used a big relay that my headlight power up and hooked all trailer wiring to it no more issues. i like jim lanes' idea.

Jim Lane

I still have some of my original Stewart Warner gauges from the 70's and they still work fine. The lighting was a bit on the flaky side but you could stick the largest bulb that would fit into the chimney and never melt the housing.
I had the theory that if it did something, then measure it.
I had a friend that owned a Speed Shop so I got everything at cost.

Stewart Warner
They do have some impressive looking faces now. The Competition
Series look nice.
http://www.sw-performance.com/products/CTG
Also the Impact series.
http://www.sw-performance.com/products/Impact

Most of all of the OTR tractors I have worked on including Transit busses have had Stewart Warner gauges as OEM however the European built Neoplan had VDO

Some of the vehicles I have owned have had interesting electrical modifications, I bought a 1975 Chevy C-10 years back and the heater quit working so as I was trouble shooting the system I found the PO had installed a unique self limiting 20 amp fuse, it was a .22 cal LR bullet in place of the glass fuse. I also found 30.06 shells had fallen down the defroster vent and jammed the defroster doors.

Years ago when I was a Transit Bus mechanic and electrician some of the mechanics who should not have been allowed to touch anything would check for shorts by jumping the circuit breaker and watch for the smoke to appear.

Jim

woodrat

When I bought my M880, I got it through the GSA auctions. It was a fire truck in a rural fire dept and it was listed as having a totally burned up wiring harness. I talked to the fire chief and he said that the running lights wiring had been torn up in the brush and all the wiring had melted. I paid $285 for the truck and when I got there, I found that a bunch of the fuses had been replaced with wads of foil and coins jammed into the fuse box. Turned out it was only one or two wires to the rear that were actually fried and I pieced things back together in the FD parking lot and drove it home. Those guys were kind of bummed out when I told them what I paid for it, and how easy it was to get it going again...

Jim Lane

Back in 1991 I bought a nice El Camino from a friend real cheap because parts of the electrical was not working and it kept blowing fuses.
All I had to do to fix it was to remove the dime from the cigarette lighter socket. This seems to be a real common but elusive problem with the slide out ashtrays.
Also knew someone who mounted a fire extinguisher on the kick panel and ran the screw through their ECM

Quote,
When I bought my M880, I got it through the GSA auctions. It was a fire truck in a rural fire dept and it was listed as having a totally burned up wiring harness. I talked to the fire chief and he said that the running lights wiring had been torn up in the brush and all the wiring had melted. I paid $285 for the truck and when I got there, I found that a bunch of the fuses had been replaced with wads of foil and coins jammed into the fuse box. Turned out it was only one or two wires to the rear that were actually fried and I pieced things back together in the FD parking lot and drove it home. Those guys were kind of bummed out when I told them what I paid for it, and how easy it was to get it going again...

It is amazing some of the things people do that we hold as professionals.

Jim

DODGEZILLAW350

I installed relays from day one as I have had other vehicles "burn up" the light switch from overloads. I have over 370,000 on my 93 W350 and not one issue with the light switch! and I am running Hella H4 headlights with 90 watt low beams and 140 watt high beams!

Relays are wired directlly off the battery, through circuit breakers and right to the headlights, bright white lights! The factory light switch is only drawing the small current to the dash lights, cab interior lights and the relay coils, no problems. I also bypassed all the high current wiring running through the ignition switch several years ago as the heavy loads like the heater blower motor melted the darn switch TWICE and burned up a few of the fusible links.

65fury

well i don't know exactly where it grounded out at, but my door jam switch, (the one that turns the dome light on when the door is open) has a wire that is bare all the way to the light switch connection and then from the light switch there is one wire that goes through the large upper wireing harness and it also burned up all its insulation and melted like six other wires any where around it together, im not sure its fixable but im gonna try since i can't get a wiring harness from anywere, anyone have any suggestions??? thanks


jason

woodrat

Just go nice and slow and keep careful track of everything as you go.

What I've got going on in mine now is intermittent stereo and map light (the one in the dash). Haven't even started to look into that one yet, I think it is a ground though, since the stereo also looses its memory each time it flickers off.

Bob Beauchaine

I just made the switch to LEDs on all running lights. Beside the lights I had to change the flasher to a LED compatible or "No Load" flasher. There is some interesting reading at www.superbrightleds.com about what color light to use behind which color lens for desired intensity. Red leds behind red lens etc - the colored LEDs were actually cheaper. My running lights are probably drawing less current than 1 1156 bulb. My next project will be to switch my trailer over to LEDS.

Bob