Help- both turn signal indicators turn on when lights are on

[JetForceF22]

Originally Posted by speedygonzales

When you checked the grounds, did you actually take measurements?

Did you check the ground connection to the indicator lights?

With regard to charging or not charging. If the alternator is working properly and all the connections are made to it correctly and the battery, there is no way anything stock should cause it to not charge correctly. Only added drain could do that. For example a cooling fan for the radiator that runs all the time, or one of those big thumping amps. A short for example, would either blow a fuse or melt a wire. Running voltage through a device that was intended to be there can not do what your suggesting.

Did you check battery/alt voltage at different points? ie. across both battery terminals, then positive battery terminal to frame rail, then positive battery terminal to engine block, Alt output post to frame rail, alt output post to engine block and last alt output post to negative battery terminal? By doing this I discovered a charging problem the dealer missed.

I don't know why your wiring is not matching the drawing. Is the drawing a different year or has your truck wiring been changed, or is the wiring of the truck faded color?

Regardless of wiring color, there is one thing that should be the same. That is, the color of the wire going to the side marker light should match the color of the wire going to the indicator light. Does it match?

Thanks for the suggestions, I'll have to preform a more detailed analysis with the multi meter. The wiring does match the diagram, now that I have that I'll be able to troubleshoot the issue further. I have a inkling that the harness ground that goes to my dimmer switch might have something to do with it.

The truck sat for 4 years, and the critters had fun with a few of the wires under the hood.

Either way, when I disconnected the marker lamps the indicator lights in the dash turned off, so for the moment they are disconnected.

Also, since you mentioned added voltage draw, I do have a lot of added exterior lights on the truck, but the majority of them are on separate toggle switches, and almost all of them are LED's, so the added draw would be nominal, at best.

It is worth noting though that I don't recall ever having this issues with this prior to the truck sitting.