Headlight short.
Thread Starter
Heel & Toe
Joined: May 2009
Posts: 15
Likes: 0
Headlight short.
78
When i turn on the headlights, even the running lights, the temp gauge goes all the way to the right. The lights work when this happens. I turn them off, the gauge goes back to reading the temp.
Curt
When i turn on the headlights, even the running lights, the temp gauge goes all the way to the right. The lights work when this happens. I turn them off, the gauge goes back to reading the temp.
Curt
Melting Slicks
Joined: Mar 2007
Posts: 2,520
Likes: 11
From: Hinckley OH
The temperature gauge works by being grounded to the engine block through the temperature sensor. I'm thinking that somehow the temperature gauge circuit must be getting extra voltage from the headlight circuit when the headlights are on.
What happens with the temperature gauge if you disconnect the wire to the temperature sending unit? Tell us what happens with the lights on and off.
What happens with the temperature gauge if you disconnect the wire to the temperature sending unit? Tell us what happens with the lights on and off.
Burning Brakes
Joined: May 2009
Posts: 1,232
Likes: 6
From: Tucson AZ
St. Jude Donor '12
The temperature gauge works by being grounded to the engine block through the temperature sensor. I'm thinking that somehow the temperature gauge circuit must be getting extra voltage from the headlight circuit when the headlights are on.
What happens with the temperature gauge if you disconnect the wire to the temperature sending unit? Tell us what happens with the lights on and off.
What happens with the temperature gauge if you disconnect the wire to the temperature sending unit? Tell us what happens with the lights on and off.
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
I would guess your dash gauge is loosing its ground when you turn on the lights.
Sounds like the dash gauge at the present is finding its ground via the instrument lights,when you turn on the lights the ground goes away and the gauge acts up.
Try removing the INST light fuse,if the gauge fails to work at all it was doing what I said above. Then you have go in and see why,probably a printed circuit issue.
Sounds like the dash gauge at the present is finding its ground via the instrument lights,when you turn on the lights the ground goes away and the gauge acts up.
Try removing the INST light fuse,if the gauge fails to work at all it was doing what I said above. Then you have go in and see why,probably a printed circuit issue.
