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why does the fuse blow when I turn the headlight switch ****?
Hello everyone. I have a 1967 cutlass convertible with courtesy light problems. None of the lights had bulbs in them for several years but I recently installed bulbs in the back seat panels and they worked. Six months later, which is today. But when I opened the door the rear courtesy lights didnt come on. I installed the driver side courtesy light and it came on but he rear still didnt come on. When I turned the headlight **** all the way counter clockwise right before the pause in rotation the rear would come on and shut right off because the fuse blows. My question is could it be the headlight switch? THANK YOU in advance
Do the headlights work as expected? I suspect you have a ground fault in the courtesy light circuit. A little probing w/ a circuit test light should identify the faulting circuit. Hopefully you have the 1967 CSM which includes the color wiring diagram. Note the door jam switches are on the courtesy light circuit & so is the clock & the ever suspicious cigar lighter. The white wire in the diagram is the ground side of the circuit which should receive no power when the doors are closed - the circuit remains open. When you open a door the door jam switch becomes grounded, the circuit is closed & the courtesy lamps illuminate. Therefore, test the courtesy lamp circuit. Pay attention to the orange wire and note it is always hot. It maintains power to the clock & the cigar lighter. Clock & cigar lighter are both independently grounded. Does the clock work? Clock is always hot & always grounded (circuit closed) - that's why it works when car is off. Cigar lighter doesn't get power until the lighter element is grounded when you push in the lighter. A bad cigar lighter (ground fault) can disrupt this circuit - check both the lighter and its wires (particularly the ground wire). With a circuit test light you can "probe" directly each wire as well as test both the ground (-) side and positive (+) side of any circuit. Is it the 20A dome-courtesy lamp fuse which blows? Test each circuit & device (lamp socket, door jam switch, etc.) along that circuit noting if the wire &/or switch should be open (OFF) or closed (ON). You'll arrive at the most likely culprit.
BTW, I've seen weirdness occur when someone accidentally installs a single contact (cap) bulb into a courtesy lamp (rear seat panel in particular) where there should be a double-contact (cap) bulb. This will automagically short that circuit as it now creates a continuous power feed. I think the rear courtesy seat lamp sockets are double-contact (cap) sockets? Double check.
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