wozny442

I’ve got a 70 442 that we had to jump start to get home one night, friend noticed tail lights weren’t working and I saw dash lights out. Replaced battery and 20A tail light fuse that was blown. Still no tail or gauge lights, 4A fuse ok, turn signals all work but blink rapidly. Head lights, dome and hazards work, no running lights work. Re-grounded lead in trunk to no avail. Could jumping have popped/fried something somewhere? All tail light bulbs good.

oldcutlass

Use a test light on the clips of the tail light fuse, it supplies power to the headlight switch and the tail lights. It also supplies power to the instrument lights through the switch.

wozny442

Thanks! So part of the switch could be bad while the headlights and dome functions still work?

oldcutlass

Maybe, but I'm leaning towards a blown tail light fuse or bad connection there.

wozny442

The tail light fuse was blown but has been replaced. Ground near trunk latch renewed. Was reading another thread about bumper grounds not being good, if that makes sense where would rear bumper ground be located?

matt69olds

The main taillight ground is near the trunk latch. Each taillight socket grounds to the taillight housing. Since none of the lights work, I’d start by checking for power on the brown wire of each taillight. If you have no power,but you have power at the taillight fuse, start working your way towards the fuse box.

The dash lamps are powered by the taillight fuse. No tailight power, no dash lights. The dash light fuse will have power only with the taillights on.

joe_padavano

The bumper "ground" is called the bumper brackets. There is no ground wire, just steel bracketry that bolts the bumper to the frame.

Rather that shotgunning things, why not try a systematic troubleshooting process. Get the wiring diagram and a test light, start at the junction block on the horn relay, and figure out where the power stops. FYI, the fuse blew for a reason. You MIGHT want to figure out what that was.

wozny442

Thanks Matt, I appreciate it. Joe, I’ve read enough on this forum to know you’re a fairly intelligent guy and are typically cordial, not sure what’s up with the condescension today. The fuse blew for a reason and I MIGHT want to figure that out? There seems to always be someone in here that is just compelled to go that way, it’s a shame.

oldcutlass

What you take as condescending is actually being blunt and trying to point you in the right direction. If the fuse did not blow again, does everything work after you replaced the fuse?

wozny442

If you say so, you are the Moderator. I believe I’ve got enough info to be done here, thanks.

oldcutlass

So is Joe P I'm done too, good luck

cjsdad

Dang, it's like that movie around here lately, Grumpy Old Men! The whole point of having an active forum is to share experiences. Good, bad, and ugly. Joe and Eric have answered these type of questions more times than most of us realize and maybe the recent isolations have begun taking their toll on everyone.

Check the grommet around the brake wires to make sure they haven't chafed and caused an intermittent short. Something Joe has mentioned before is to make sure the emergency flasher switch is not stuck half-way on. The rapid turn signals usually means a bad bulb on the turn signals so make sure you haven't replaced a dual element brake/signal light with a single element marker light. A single element light has a large contact in the center of the base of the bulb that can short the brake light circuit with the parking light/dash light circuit. Just a couple thoughts.

wozny442

Thanks!