Electrical issues with 72 Charger, brake lights and turn signals dim or off.

[Frankie 72]

Hey!  My 1972 Charger Rallye (400 4BBL) is giving me fits with the electrical system.  My brake lights, rear license plate lights and turn signals work sometimes, then not at all or are dim.  The turn indicators on the front fenders are alos either on or dim or not at all.  Headlights seem OK.  I have been trying to find a bad ground.  Any body have any ideas out there??

[Nacho-RT74]

well... the headlights get the ground from a wire attached straight to the radiator core support. The rest of lights get the ground from chassis. Too much casuality front and rears are on same deal what makes me think a bad main ground.

Check the radiator core support ground provision. IT IS POSIBLE the headlights ground wire is making a good conection with batt neg wire ( both eyelet terminals ), BUT not with chassis provission there

[Pete in NH]

Hi,

Yes, I would be looking for bad grounds also. As I recall there is also a connector lurking under the trunk floor mat that may have become corroded. I recall all the rear lighting is routed through this connector. Way back in 1971 when my Charger was brand new and under warranty I lost all my rear lights. It took the dealer tech. a really long time to find that trunk connector and fix the bad crimping on the connector pins. So, see if you can find that connector. Also, look at ground lugs under screws and clean them up as well as lamp sockets that become corroded as well between the bulbs and sockets. I always make it a point to install new bulbs with a little dielectric grease on the bulb base to ward off the corrosion.

[Nacho-RT74]

Pete, since he is telling got a Rallye, rallye-R/T tail lights source the ground by chassis because housings are pot metal... 72 standards and SE too. Standard 71 tail lights and all 73/74 are, with a wire attached to the driver side ground provision into the trunk since housings are plastic on all these.

rear tail light plug its over driver side trunk floor pan extension area.

I'd look first the main ground provision at radiator core support first since is a single point to check, and checj that can get better everything on the car at the same time.

If problem persist then would check every point individually. Parking lights get the ground through mounting screws SPECIALLY the top one what it got a theeted washer. And as stated, tail lights through chassis at bumper too

[Frankie 72]

Thanks for the tips!  I will be working on her over the next few days.  I'll let you guys know how I make out.