On my 64 Skylark if I turn on the headlights the dash lights and tail lights go out? I tried to follow my wire diagram but it makes my head hurt! Any thoughts? I already replaced the headlight switch.
usually when you have a dash lite problem it's with the dash grounds.in your case the circuit that feeds power to the taillights also feeds power to the dash lites.the reason this was designed this way was to alert the driver that his tail lamps where not working.if it was just the dash lites I'd say a faulty ground.this is not the case here and it looks like your loosing power to the headlite switch.using a test lite check your tail lamp fuse on both sides to assure your getting continuity.if its ok then check for power at the headlite switch .The large(red 12 Gauge) feeds the switch.do this first because this is the power feed for the headlamps.the dash lites are fed from the headlite switch reostat so check the dk green 18 gauge wire for power when the dash lites are on,this feeds the dash fuse and the fuse also can be checked.the next step is brn/white stripe wire feeding the h-lite switch.this feeds power from the fuse block all the time and if you have power there then check the Dk Brown 16 gauge wire coming out of the h-lite switch.with the switch on you should have power.this wire leads to the t-lamps.if all checks out then you may have a defective switch.it's possible to have this happen but I bet you find you have a combination of 2 problems aggravating each other.make sure as you do these test you have someone watch your outside lites.movement sometimes causes a temporary fix.Bill
Bill thank you very much for the detailed testing. This is make it easy for me trouble shoot. I replaced the orginal switch because I thought that was the issue so I will assume the switch is good and go from there. I wont be able to work on it for a couple of weeks but I will report back. Thanks again:TU:
I have a similar problem on my 64 skylark convertible and plan to follow your trouble shooting advice. The tail lights and dash lights don't turn on even thought the headlights brake lights and signals work. I also understand that tail lights are not fused but rather are on fuse able links. Do you know where the fuse able links for the tail lights and dash lights are located? Can you direct me to a wiring diagram?
It's a long shot--but I'll tell my story. 84 Olds Delta 88. Headlights off= brake lights worked fine, but front parking lights and dash lights would come on when the brake was applied. Headlights on= dash lights worked, front parking lights worked, but brake lights would not go out. The cause was an incorrect brake light bulb. Go figure. True story.
Well the problem was it was grounding out under the carpet. The little metal tab that holds the flat wire harness for the rear lights. It rubbed through the plastic and would ground out??? Taped it up and move the harness all is good.
Funny story--I drove a '64 Skylark convertible in college, and had trouble blowing fuses to the taillights. I could go months without a problem, or have it six times in a weekend. One night as I was picking up friends, a girl climbed into the back seat and as soon as she plopped down, 'pop' went my dash and taillights. Had a chafed wire under the rear seat. Patrick
