dschallock

Hello,
So I bought a replacement dome light bulb. Tried to carefully remove the plastic dome light cover and it crack (dang it! now I must order a new one). Any way when I plugged in the new bulb I noticed 2 things. 1) the bulb was gettng really hot.... like lick your fingers ouch it and hear it sizzle hot... is that right? and 2) the light stayed on. The doors were closed. The head light switch was not turned into the dome light on position. When I open the doors the other lights come on and then when I shut the door they all go out except the dome light.
Is the heat normal? Any ideas why it's staying on?
Thanks,
Dan

Bluevista

The heat is normal as long as it's the correct wattage bulb.
Ever see the roofs of cars with the paint burned off above the dome light from leaving the door open or leaving the dome light on with the switch for too long?

Here's the diagnosis procedure from the '71 chassis service manual.
If you don't have an Olds chassis service manual I highly recommend that you pick one up, one of the best things you can get for your car.

wel187.jpg

Higgins

Make sure you have the right bulb. Did the original have 1 or 2 contact points?

MDchanic

The "cold" terminal of your dome light bulb is somehow making contact with ground, instead of with the switched grounding wire.

There is one "hot" wire (Orange), from the CTSY fuse, which is on at all times, and one "cold" wire (White), which is grounded by the switches to turn the lights on.
The side of the bulb that should be in contact with the White wire is touching ground (a screw perhaps) instead.

- Eric

dschallock

Thanks, I'll check the ground, and my chasis service manual for the diagnosis. I looked in the book last night but I thought I couldn't find anything on the dome light. I'll look again. There should be a page like that one from the 71 service manual I assume.

In terms of the bulb and the heat. I pulled the original bulb out and it said GE 211-1. The replacement bulb I bought from O'reileys had one of those areas with a book where you look up the year/make/model of your car and it gave you a new number from their bulbs. The new bulbs are not GE they are Sylvania brand. And the number it called for is 212-2. If the number had been something totally different like GF48 I wouldn't have thought twice about it, but being so close to the original GE number makes me wonder if it is really the right bulb or not.

Thanks again for the tips, I will try and diagnose the ground today and report back.

-Dan

MDchanic

Dan - I'm not sure, but I think that page may have come from the Fisher Body Manual. It's good to have that one, too...

As for the lights, yes, they DO get DARN HOT. It is very common to see GM cars of that era with the center portion of the white dome light lens melted out, or, as Blue mentioned, even to see the paint in the roof above the light damaged .
Because of this, it is a good idea to block the door switch or otherwise turn the light off if you're going to be working on the car with the door open for a long time.

Good luck!

- Eric

dschallock

It seems like there should be a modern bulb that would fit in place of the original that would be cooler without having to change the whole dome light fixture.
-Dan

MDchanic

LEDs.

dschallock

ok so I found a pretty cool website with LED replacements for classic autos.
Go to http://www.superbrightleds.com/ and then click on automotive replacements. It lets you put the year and make and model of your vehicle.
The really cool thing is you can even select the color of the light you want. They have a warm light option so potentially it could look less like an LED and more like it should.
Check it out, could be a cool option for the high heat problem.
-Dan

MDchanic

They're the high-priced outlet.

If you look around, you can find pretty much everything they've got somewhere else for less.

- Eric

dschallock

an update on the dome light issue.

I discovered tonight that when I pressed the passenger side door switch by hand that it turned the dome light out along with the courtesy lights, but if I closed the door it would shut off the courtesy lights but not the dome light.
I don't know why this is happening but I figure it has something to do with metal to metal contact of the switch and a ground issue.
As a temporary solution I took a small tab of adhesive Velcro (I used the fuzzy side) and stuck on the inner jam of the door so that when I close the door the velcro makes contact with the switch instead of the metal door. It seems to work fine now. But I don't know what needs to be changed. Is that switch bad?
-Dan

442much

This might be something you've looked into but...turn the headlight switch to the left. If the headlight switch is turned to the extreme right the dome light will stay on. To dim the dash lights, and turn the dome off, turn the switch to the left. Then shut the door to test it.

442much

Example: my tail lights are supposed to be 1157. For a brighter light, I changed them out to a 2157

MDchanic

Either the switch is bad, or it it not turned out enough toward the door.

If you can't back the switch out a few turns, and your door is lined up properly, then try another switch. Or you could just do what you did and put a space on the edge of the door.

- Eric

Lady72nRob71

X2. The velcro acted like a spacer and pushed the switch in more.