I have the above problem with our '76 Cutlass. It sounds like the dimmer switch to me, but I thought that I would ask the ClassicOlds brain trust.

By the way, our car has the column-mounted dimmer switch. How hard is it to replace those (assuming I can find one)?

Jeff

 

Probably the headlight switch, with a much-lower probability of a short in the highbeam circuit, triggering the headlight switch circuit breaker.

- Eric

 

Eric,

Thanks. I doubt that it is a short since when I switch back to low beams the headlights come back on instantly.

Has anyone ever replaced one of those switches? How much of the column must I disassemble to to do it? Photos of a replacement switch indicate that it comes with its own wiring harness, suggesting a deeply-"buried" connection.

Jeff

 

I would check for voltage at the headlights first. Chances of all the high beams being bad are slim, but I have seen it happen.

 

x2 .definitely seen this happen,also had one with only hi-beam and it was a ground in the headlight harness.i thought those dimmer switches were mounted outside the column near the brake pedal arm not inside the column.

 

Eric and JC,

I just replaced the high- and low-beam headlamps (with Sylvania XtraVision) as well as the adjusters and springs around 6 months ago, so I doubt that's the problem.

This car was ordered by a wealthy man's 18-year-old daughter who checked just about every option on the list; on-column dimmer switch was among them (first year I think). But did she order the rally gauge package? Nooo . . .

Jeff

 

bad ground or grounds?

 

Perhaps, Mark . . . but why would a bad ground cause the low beams to go out when the high beam switch is triggered? High beams don't come on, either, of course . . . which led to some exciting moments coming home from a car club meeting last night.

Jeff

 

ive been a body man for a long time..all i can tell you is...bad grounds really do weird things..things you cant believe it will do...ive seen your situation many times..and we scratched out heads...went back checked grounds and made sure they where clean and 75% ofthe time..its was bad grounds...not always..but when ya just cant seem to make sense of it..i always start with fuses...then fusible links if equipped..and then straight to finding my grounds...

 

Okay; thanks, Mark. I'll check the grounds.

UPDATE:
Factory Service Manual indicates that headlamp grounding is via Main Instrument Panel Ground (12 ga. black wire). Any idea where this is located?

Jeff

 

theres a sheet metal ring that goes around the switch and is screwed in...it connects stuff in the plastic dash like switches and gauges so it has a real ground..and it connects to the metal body usually with a screw and wire..

i cant say on a cutlass..but know for a fact they are in GTOs and when a person leaves them out...instant gremlins

 

Which switch, Mark?

Jeff

 

one around the headlight and one around the wiper...let me see if i can find a pic

PM oldspackrat..he has a bunch of dash stuff loose..he does alot with them..he would know for sure

 

PROBLEM FOUND!

I checked the ground, but it was clean and tight; put some dielectric grease on it anyway and re-tightened.

Upon trying to disconnect the switch from the dash wiring harness, the problem was revealed: heat build-up at the dimmer switch's three-terminal connector (at bottom of steering column) had melted everything into one big mess!

Yes, it needed the switch replaced (AC Delco #D6260D, GM #19106994) but I also improved the integrity of the connection to the wiring harness (where the plastic connector had melted) while I was about it.

Considering the level of difficulty involved in this job, I would not mess around with cheap switches. I got my OEM Delco switch in two days from Amazon Prime for $29.00, no shipping.

Because the Factory Service Manual is of virtually NO HELP with replacing this switch, I am soon going to post a separate thread about how to do it.

Stay Tuned

Jeff

 

Glad you found it!

It's great that you'll be posting information about this - I and many others of us have never had one of these "later" cars, so we can't be very specific about how to fix the signal-stalk switches when they go.

- Eric

 

X2

 

Good to hear you found the problem Jeff,
Thanks for posting your headlight issue along with the fix as well, as Eric mentioned this will really help out many of us here with the 73-77 model years.
Looking forward to the how to thread.

Cheers
Eric

 

Glad you found your problem Jeff. I'm a member of wild about cars & at this time there is no '76 manual in their data base but they do have a '75. In section 15 for the accessories they do show that switch setup . It says the hand dimmer was for only the cutlass salons&(omega salons,anyone have one of those??!!)I don't know if you could get it as an option on other models.Pontiac grand-ams of that era had them too. The text section does say that the hand dimmer is wired differently from the foot dimmer in that it switches the grounds at the switch,not the hot wires like the foot dimmer

 

Another area to check is the dimmer switch.

They tend to corrode, and the same thing happens.

 

Okay, guys and gals, here is the link to the new "how-to" thread:

https://classicoldsmobile.com/forums...tml#post933358

Rob,
Your manual sounds to be the same as mine. It mentions the same points . . . but fails to mention anything about how to get the new harness into the column or any other details! Hence the above link.

Jeff