Hitman's Pontiac Trans Am Forum

Trans Am Information => Trans Am Tech => Electrical => Topic started by: BadBirds on July 12, 2006, 11:03:23 PM

Title: tempermental headlights
Post by: BadBirds on July 12, 2006, 11:03:23 PM
i have a 1981 ta with a 400cid out of a 78 ta. occasionally on a good day my headlights will work just fine then somedays they wont work at all. is it a bad connection ,bad ground or what? im clueless.
any help would be greatly appreciated.
Title: tempermental headlights
Post by: ta78w72 on July 13, 2006, 10:07:10 AM
It's really hard to say.  But what you need is 12 volt to the light and a good ground.  I would start measuring at the switch.  Get a service manual and figure out where the wire to the headlights is located and measure for voltage there.  Also, measure the voltage from the fuse box to the switch.  If you've got voltage at the switch, but the lights don't go on, you need to look further down the circuit towards the light.  Check for voltage at the lights.  If you've got 12 volts there, you can start hunting for a bad ground.  But you just might have a bad switch.  

If you're in too much of a hurry to wait for a service manual, let me know and I'll check the color of the switch wires you need to measure.
Title: headlights
Post by: BadBirds on July 13, 2006, 10:15:32 AM
i do have a haynes repair manual with the wiring diagrams that i will use. appreciate the help.
Title: tempermental headlights
Post by: TRAN5AM on July 13, 2006, 11:59:22 AM
Mine were flaky when I bought it.

All I needed to do was pull the connectors off the back of the bulbs, spray both the bulb contacts and the connectors with a heathy dose of WD40, then re-seat the connectors fully.

No problem since.
Title: tempermental headlights
Post by: Eagle 1 on July 13, 2006, 12:52:34 PM
Sounds like the dimmer switch to me.
Title: tempermental headlights
Post by: TRAN5AM on July 13, 2006, 01:55:13 PM
The WD40 trick might work for that too.
Title: headlights
Post by: BadBirds on July 13, 2006, 10:04:26 PM
Eagle 1, when my headlights do work which is rarely the dimmer switch works just fine. but i will try the wd-40.