mrbobs48 Posted July 7, 2014 Report Posted July 7, 2014 Are the tail lights suppose to be on when light switch is pulled to parking lights? Also I have -6 volts to dome light, but no light. New bulb in dome socket. Is there a ground wire on the dome light? Quote
DonaldSmith Posted July 7, 2014 Report Posted July 7, 2014 Yes, the tail lights are supposed to be on when the parking lights are on, so that the car won't get hit on a dark street. There are two ways to power and control a light. 1) Ground the light to the car body, and put a switch on the "hot " wire. For a single switch, this saves some ground wire. But for more than one switch, as for one at each door, each switch would need two wires, one hot wire from the line (the battery) and one switched wire to the load (the light). At some point it takes less wire to go to (2). 2) Run the hot wire directly to the light. To ground the circuit, run a single wire to each switch, and have each switch complete the circuit to the car body for ground. Any switch in the "on" position will light the light. I think (2) is the more common circuit for a dome light controlled by each door. 1 Quote
DJ194950 Posted July 7, 2014 Report Posted July 7, 2014 On a p-15 the base of the light is supposed to be grounded to body and a hot supplied by door switch (s) and/or pillar switch(s). Interesting as the P-17 on did the opposite. Hot to the light full time and switch (s) provided the ground connection.! DJ Quote
janan5243 Posted July 8, 2014 Report Posted July 8, 2014 If you have a pillar switch on the drivers side, the switch could be corroded. mine was. I took it apart & cleaned contacts. works fine now. my car is positive ground so switch completes circuit from body/frame to light. Quote
mrbobs48 Posted July 9, 2014 Author Report Posted July 9, 2014 Thanks for the info everyone. Took my switches apart and cleaned them. My dome light works great even the door switch. Now on to the brake park light thing. I think the brake light needs a ground. My new wiring harness had one wire going to the bulb no ground wire. Quote
bobjob55 Posted July 9, 2014 Report Posted July 9, 2014 ..I'm thinking ,, if there is only 1 wire to to brake lite ,, ground goes to body thru socket of lite at the 2 prongs that holds bulb in .... Just a small amount of corrosion will make connections bad ........ Quote
desoto1939 Posted July 9, 2014 Report Posted July 9, 2014 I had a similar issue. I had working taillights, brake lights and turnsignal lights prior to having the car stripped and painterd. Then reassembled the fenders and put both taillights back into the fenders. The right rear brake light would not work. I then connected a jumper clip and wire to the body of the taillight housing and then found a good bare maetal spot on the frame. AND guess what the lights worked again. After repainting the fenders I lost the good ground. So now I have a sperate ground for that light. GROUND, GROUND is so important. BAsically the car is the ground and the wire is suppling the electricity and the car is the return. Keep a good ground on the car. Rich HArtung desoto1939@aol.com Quote
mrbobs48 Posted July 9, 2014 Author Report Posted July 9, 2014 Made 2 ground wires and hooked them in the side bulb tail light brackets and ground the other end to the trunk floor. They work great. Now on to the instruments lights, taking the under dash switch apart and cleaning it. Hope it works. Then its 100 % ready for a drive. Quote
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