The Flash

Hi
1966 olds 98 convertible
left turn signal light is on and dim when not using the signal light
when the turn signal is flashing on the left dash its not as bright as right one
when the high beams are on the center has a red high beam light im guessing that's what it is and it dims on and off when the turn signal is on.
where would be a good place to start looking for the short?
thanks

The Flash

did some more testing
when the dash lights are turned low the dim light goes away
when the high beams are off the red light on the dash is on
the plug on the head light dimmer switch is melted but if i unplug it the lights go out

thanks

Oldsguy

Check all your turn signal lamps and sockets. Make sure there is no corrosion, loose wires, shorted wires because of some physical damage (crimp or split, etc). Finally, it might be the headlight switch but the melted plug could have been caused by heat because of the current from the short someplace else. I do agree that it is probably a short.

The Flash

great I'll take a look
I did go through the tail lights and clean the sockets and replace 2 bulbs.
I'll check the rest and I am picking up the melted dimmer switch pigtail as it was arcing pretty bad when I touched it. I'm glad it did not catch fire during her maidan voyage Friday
thanks again

Allan R

That's the headlight switch. The rheostat changes resistance as the headlight **** is turned. It shouldn't be affecting your signal lights in the slightest

Then someone has been either messing with the wiring or your have a crossed wire somewhere. Replace the headlight dimmer since it's kaput and retest.

O'Reilly:


If your high beam indicator is showing on the dash with the lights off, there's something seriously wrong there. Check the connections on the front headlight harness for frayed or spliced wires. Also check your harness ground to make sure it's not corroded. That could easily explain the pulsing you're getting in the left signal light.

These cars had a red high beam indicator up till 1971 when it was changed to blue.

Yellowstatue

My vote is for a bad ground.

Allan R

A bad ground won't activate the high beam indicator though.

The Flash

headlight switch has a crack in the porcelain dimmer part on front but I'm having problems finding a switch. all the ones I look at have a smaller hole where the front retaining nut screws in. any ideas or part number
thanks

Allan R

RockAuto 1961-67 Oldsmobile

The Flash

found the problem
looking at the back of the dash spedo i was checking and making sure the circuit board was not cracked or melted.. that's when i noticed that one of the screws that is next to the left blinker light that holds the circuit board down was missing and it was a ground point.
pulled another screw to find one that would work and it looked like a small sheet metal screw.
i cut the tip off and it fit perfect even looks like the stock one
all the lights work like normal now even the high beam indicator shows the correct red light when on high.
also
i added relays to the head lights and they are so much more brighter and the dimmer switch is not even warm now.
thanks for the help and advise
now on to the next fix

Octania

I have seen really weird behavior like this with a bad ground somewhere. The electricity will go "backwards" thru other circuits [bulbs are the most noticeable] and weird stuff results.

It appears that a dash lighting ground was the cause of that part of the problem.

Arcing and melted terminal body to me indicates that the terminal was loose on the lamp tang, and the loose/ corroded connection then makes heat. Clean tang and new tight terminal should fix all that. I use silicone grease on electrical connections to ward off oxidation.

joe_padavano

^^^^THIS!

Bad grounds and resulting sneak circuits are nearly ALWAYS the cause of strange behavior like this, primarily due to the common ground between the filaments in the 1157 bulbs. It is almost NEVER caused by the dimmer or headlight switches. Just look at the wiring diagrams - these switches can't cause problems like this, especially if the lights are otherwise working correctly. I was going to guess a bad ground at one of the turn/park sockets, but a bad ground at the instrument cluster will do the same thing.