Electical Question ~ Headlights & Stop Lights

[JustGrim]

ok....so I am out in the '76 and it gets dark....dim lights work fine but when I kick the High Beams on....nothing.....Black as pitch. Plus upon checking further...no brake lights.

I thought about the floor dimmer (this was the problem on the '66 Stang) but that is not it...fuses were fine....looked for a relay but could not find one (anyone know where it might be?)

Symptoms: Without lights on, the brake lights work and the turn signals flash (very very slow--did not change even with a new flasher) unless the brake is applied then the turn signals don't--------turn on the headlights and no brake lights or turn signals. High beams and no lights at all other than side marker lights and license plate.

There is a "Back Up" switch that has been installed at some point. I have thought that maybe this could be the cause.

Any assistance on where to look or what to try next is appreciated. I would hate to just be able to drive her during the day light hours.

[Guest]

check for loose grounds, or grounds that are corroded and not making good connections

[mdeanr]

dad says to try a new headlight switch since all the other lights run through the headlight switch. if the switch you are talking about is a white switch under the dash it is a factory installed switch on all S&S's. it is for loading and unloading the rear.

[mdeanr]

also you might try installing a heavy duty flasher fuse. i had to put one on my jeep because the original one was too weak.

[JustGrim]

new switch

Got the heavy duty flasher as I thought about that. That probably is not the cause for the main headlight and brake light issue.

I was afraid it might be the main headlight switch. Looks like I get to tear into the dash after all!!!

Anyone out there with a surplus?

[mdeanr]

try this.....i hope it works.

http://www.partsamerica.com/ProductList.aspx?PartType=408&PTSet=A&SearchFor=Headlight+Switch

[JustGrim]

Parts Site

Thanks Mac....one is on the way to my house and site bookmarked.

[mdeanr]

cool......np........hope it does the trick.

[northgahearse]

i might have a switch off the parts car still but then you don't want to wait till the bash next year to get it huh?

check the wires going to the highbeam for any sign of wigwags ever being on the car i found that bug on one of mine

looks like they had the wiring going to a relay to stop a backfeed of power to the light switch. they just cut the feed from the wigwag flasher to the lights and left the relay and it had some funky stuff going on ... i found the relay behind the grill took it out rehooked the highbeams and its been good togo

just a idea 4 ya

as far as the flashers being slow check all the grounds for the lights themself the 68 had a rust gunk build up so they had no good body ground i had to run a new wire and its been flashing like a perv on a fridaynight just fine

i have gm shop books on all but the 68 so if ya need any thing looked up let me know

good luck

[Zachary]

That sounds similar to something that happened on my 71.

I would suggest that you check the wiring harness that goes down to the actual starter since Caddies routed damned near all electrical contacts through the starter. A lot of times the wires hit the engine or the exhaust and the heat melts the insulation, causing weird ass grounding issues. There is also a coupling for that harness that sometimes comes loose and resides just around the firewall area in front of your heater core outlets, check that and make sure it is tight.

[BIGEVIL]

Anyone check with Kaptinkaos? This sounds right up his alley.

I had to replace my headlight switch on my 70. I bought the switch from the dealer. They had it on the shelf believe it or not. Replacing it took about an hour. I ended up removing the whole top dashpad (which is very easy) , that made the repair go smoother.

[JustGrim]

Tried the new headlight switch....no luck. That was a barrel of fun reaching way up on top to push the little release pin to let go of the headlight knob.

Next it is to the rack and Zack's possibility....maybe a fusible link near the starter....

[mdeanr]

damn.......i was hoping the switch would fix it.

[JustGrim]

SOLVED!!!!!

There were actually two problems...the first which corrected the taillights problem was a ground problem (kudos to Ryan Ricks)...but the damn headlights still would not work on bright....

That turned out to be a wire that had chaffed (hate it when it does that) on a sharp metal edge it ran next to and grounded out.

Now lets see what else she throws out to fix next.....

[mdeanr]

lol let's hope nothing else.