Onemoparnut

Sometimes when I have the ac on with the blower on high it will just speed up all of a sudden. It is a night and day difference when it does it. Then also sometimes my dash lights are a little dim then they will just get bright like they should be all of a sudden. Is there a main ground for things under the dash? Is the blower motor grounded under the hood instead of under the dash? I really need to get a fsm for when I have these wiring issues.

Mark Nixon

There is a plate that's bolted to the main dash frame, which the 2 or 3 grounds are nutted to.
This plate is located to the right of the brake pedal and is usually a gold irridite in color.

Check the grounds to the core support and the one behind the head, on the firewall.
There is also one from the right front corner of the bed that is clipped (sometimes screwed) to the cab corner, which is almost NEVER present after this long.

Also, check the blower resistance elements above the glovebox, mounted to the upper cowl area, sometimes they get weakened from corrosion or heat cycling, and will vary resistance due to heating and cooling.

Mark.

Onemoparnut

Thanks mark. It is odd cause it will be running and then all of a sudden the motor will just speed way up. I will check all the grounds.

archer39

the blower motor is grounded though the harness it connects to under the hood of the truck. The wiring diagram does not show where it grounds too but it would be easy enough just to put a pigtail on the factory wiring and ground it some where you want it. It also would be a good excuse to throw the blower motor on relays than you can take advantage of its capability.

Onemoparnut

I want to do the headlight relays and the blower motor relay but I have so many projects already. There just aren't enough hours in the day.

Jim Lane

This sounds to me like your alternator may be intermittently overcharging and giving you excessive voltage at times, I don't think the dash lights have ever been very bright on a 1st. Gen Dodge.

Jim

Onemoparnut

My dash lights are bright Brandon has seen them.

Crossy's son

They are intense

Jim Lane

What do you mean, have you done something to make them INTENSE like different lamps or do you mean they get really bright?

A #194 lamp should not be intense unless it is being overdriven.

If your alternator is overcharging it can destroy your computer, radio or anything connected to the DC buss.

What are the headlamps doing while all of this is happening?

Onemoparnut

The headlights don't get any brighter and the volt meter in the dash does not change either. The truck is not over charging. I have not changed the dash lights they are stock also.

Crossy's son

The dash lights are stock but for some reason his are really bright and light up the cluster like really good.