Vannin' Home Forums Dodge Troubleshooting (Dodge) revolting morning

Well, you've certainly got a novel failure there. Mopars are more typically known for things not turning on than the other way around...

There is some unfused power going to the head lamp switch, so the switch and the wires immediately behind it are a prime suspect for lights that are stuck on.

The rotary dimmer switch circuit feeds the instrument panel lamps, & the radio & clock lamps. The power for that circuit comes from the fuse block. Since the head lamp power is also fused, but on a separate fuse, and the instrument panel lamp wires don't go to the bulkhead connector, perhaps the wires for the two circuits are melted together on the way to the fuse block.

The odd thing is that most of the wires are small enough that they wouldn't appreciate feeding the head lamps in addition to their normal load... I'd expect some *super* hot small wires and sagging insulation if the 12 volts is coming from one of them.

The Instrument panel lamp's power terminal on the back of the head lamp switch is conveniently labeled "I". Follow that wire back to the fuse block and see if anything turns up.

If the Radio and Clock circuit were shorted to a 12 volt wire they would backfeed the instrument panel lamps. Their terminal on the switch is labeled "R". Might be worth tracing that wire. A lot of stereo installs are real hack jobs.

The head lamp switch terminal which feeds the head lamp dimmer switch is labeled "H"; I'd follow that wire too, and very carefully.

You didn't mention whether both the high and low beams were stuck on. That might help narrow down whether the issue is as far back as the bulkhead connector.

You said you've got new headlight switches... just as an aside, the body of the switch may need to be well grounded to the metal dash in order for some circuits to work correctly. I've seen terminal "D" be connected to a wire to ground, but I've also seen it be bonded to the body of the switch, with no separate wire. I'd think that would have more to do with the courtesy and dome lamps than the instrument panel lamps though. Should have no effect on the head lamps.

I also had some odd things happening in my 81 Dodge van when I first got it due to some overheated wiring at the ignition switch. Several contacts in one of the removable connectors had gotten super hot and melted/carbonized the connector and a couple of the wires melted together. It wasn't super obvious - I didn't discover it until I went to pull the connectors to get the wires out of the way make it easier to do some work under the dash and found it. Fortunately one of my friends had a Ramcharger of a similar vintage which he was junking, so he let me pull that section of wiring out, which was a perfect match.

Good luck!

Clear skies!

Sounds like a sticking relay, I had this on an off road lamp setup once, relay gets hot and sticks, holding the lights on.

I have a factory wiring diagram for that Dodge & spent hours looking at it & seeing where each & every wire goes.
Dave unhooked the headlight switch,the dimmer,& the instrument cluster & the headlights remained on.
The lights shouldn't work with the dimmer unhooked,but they did.
Where did your info come from Ram4Ever? Just curious,because a lot of that info you posted just isn't the way it shows in the manual for a 75.
Thanks for all the info everyone,we will get it figured out. Brad

I was looking at my 81 Dodge van service manual's wiring diagrams. I do have one earlier service manual, I think it's a 78, but it's wiring diagrams are nearly worthless, so I don't even bother with it most of the time. I also got some info from a Dakota manual; they were nearly identical to my van in their wiring.

The thing to keep in mind is that something is *incorrectly* feeding voltage to those headlights, so the diagrams are only going to give you an idea of where to start.

Since most of the wiring in a Dodge tends towards undersized, something under the dash should be getting noticeably hot... Keep looking & feeling your way along till you find it.

I'd even pull every single fuse out of the fuse block if I were beginning to troubleshoot an issue that severe. The ignition switch and heater fan wiring would be next... they're about the only circuits which have heavy enough wiring to not overheat substantially when a heavy additonal load is thrown on them.

Good luck,

Clear skies!

I had that problem before and on my old 75 dodge or my 73 it was my dimmer switch on the floor that as causing the problem. It still might be the dash switch but I don't think it would go much deeper than either switch. there are alot of wires connected to both, especially the dash light switch. Gut feeling it's one or the other.