'69 Buick help!

['69buickgs]

Im new to all this restoration but i just got a 69 gs and it is running but one of my brake lights and reverse lights arent working. is there any place i can look that is common so i dont have to try and find the wire all the way to the fuse box? I also already tried new bulbs. any help will be greatly appreciated.

thanks,
Clayton

[Bob]

The back up lights should get the signal from nutral safty and back up light switch mounted on your steering column. But because you are having a brake light problem too, it would seem more like a wiring problem, probably in connecting plug inside the trunk... maybe...

['69buickgs]

yeah i think it is a wiring problem because the brake lights will work with out the headlights on but when the headlights are on, one brake light on the right will cut off. i redid that plug and that didnt do anything so im sure the problem is somewhere inbetween that plug and the actual bulb connection. but on the reverse lights the right one and middle one work could that still be a problem with the back up light switch?

[Rattus]

OK, let's get clear on the proper nomenclature so this is less confusing...

Headlights on means TAIL lights are on in the back, yes?

Brake lights come on when you step on the brakes...or use the emergency flashers. Same filaments are hot for brake and emergency lights, in the back.

So, if the taillights are on, but you step on the brake, one of them goes out? Is that what you mean? Or if the brake lights are on, and you turn on the headlights, a brake light goes out?

I don't recall what the '69 looks like in the back, but my '68 Skylark has two tail/stop lights per side and 1 backup light per side. If one backup light comes on, the switch is good. Anything that happens with lights going out when another light is energized is usually a bad ground.

You may have to take the back bumper off to fix a bad ground properly. The whole bucket of bulbs is bolted in from the inside, and you'd have to be a "16 year old Chinese gymnast" to contort your fingers enough to get those nuts off while the bumper is still on.

['69buickgs]

yes you have it right and the 69 does have the two brake lights on each side like your 68. im pretty sure my problem is in the bumper like you were saying because im getting great power all the way up to that rubber harness so i has to be from there on. i will try and pull that bumper off tomorrow if i have time and hopefully get those lights working so i can get an inspection!

thanks for your help

[Special_Deluxe]

How are the sockets and the contacts inside? sometimes they get corroded or pushed inwards to the point of not making contact.

Get a 12 volt test light and test for juice right at the socket. Hook the test light up to a good ground and have a helper activate the brake lights with the headlights off, and then with the headlights on. If the test light functions normally it's a ground issue, if it misbehaves in the same manner as your taillight, it's a hot-wiring issue (either somewhere in the trunk wiring or else right at the socket). Do the same test with the backup light.

If it's a taillight ground issue, since three of four lights are functioning correctly, we can assume the problem is the black wire leading from the socket to the wiring harness. Since these wires are tucked up well out of the way the main suspect is corrosion where the wire connects to the socket. If you're lucky, or limber, or both you may be able to reach up to the socket and *gently* wiggle the socket connections there....might be enough to re-establsh a ground, might not. Still worth a try before taking the bumper off. Note that the inner taillights are somewhat acessable thru the fuel filler door, the outer ones less so....

If it's a hot-wiring issue it might be a bare wire touching ground somewhere. Try *gently* moving the wire harness as your helper stands on the brakes, and see if the lighting issue changes any. If it's your lucky day the problem could be relved with no more than a quick application of some electrical tape If not, it's usually socket connections again. Usually can't fix hot-wire socket problems by wiggling but again, it can't hurt as long as they're not manhandled at all.....just a little wiggle, nothing drastic. If it's corrosion it might help at least in the short (excuse pun please ) term.

Same for the backup lights. Test light first, wiring harness second, socket connections third. If none of that helps the sockets may indeed need to be replaced which means dropping the bumper to get at them. Big job that.

I have a 1970 shop manual diagram (cutaway drawing) of the rear bumper lighting assemblies, can scan and upload next time I'm home if that helps at all. Let me know!

Good luck and hope this helps.

['69buickgs]

thank you sooo much that gives me some good ideas and il test it out when i get home and hopefully it willl work.