On my 67 D100, my taillights don’t work when it is cold until I have driven a mile or two, of course with the cabin heater blowing. I think they come on immediately if it is warm enough.
At first I thought the issue might be in the steering column turn signal switch area but I don’t know why the tail light circuit would be related to turn signals at all since turn signals alternate with brake lights, not tail lights.
This has been a bear to diagnose since they start working after a few minutes.
Any thoughts what might be doing this and how to correct it?
Jeff
Tail lights don’t work until warmed up?
- 67D100Pickup
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Re: Tail lights don’t work until warmed up?
Maybe corrosion or crud on headlight switch terminals, connector, or internally. Do the front running lights do the same? If not, won't be the headlight switch. Also check firewall connectors for same.
- dodgeboykim
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Re: Tail lights don’t work until warmed up?
Tail Light/running lights do not go through turn signal switch. Only Brake/turn signals do.67D100Pickup wrote: ↑Tue Nov 28, 2023 10:06 amOn my 67 D100, my taillights don’t work when it is cold until I have driven a mile or two, of course with the cabin heater blowing. I think they come on immediately if it is warm enough.
At first I thought the issue might be in the steering column turn signal switch area but I don’t know why the tail light circuit would be related to turn signals at all since turn signals alternate with brake lights, not tail lights.
This has been a bear to diagnose since they start working after a few minutes.
Any thoughts what might be doing this and how to correct it?
Jeff
Pull headlight switch and have a look at it.
Or its a bad connection in T Light circuit.
My truck is younger than me.
66 W100. 70 D 500 , 69 Hiab Speed Loader. 96 Ram 3500 Club Cab Cummin's 5 spd. 97 Ram 1500 Club Cab 5.9 gas auto. 83 W200 LB Propane 360 auto 09 Yammy Rhino 700.
66 W100. 70 D 500 , 69 Hiab Speed Loader. 96 Ram 3500 Club Cab Cummin's 5 spd. 97 Ram 1500 Club Cab 5.9 gas auto. 83 W200 LB Propane 360 auto 09 Yammy Rhino 700.
Re: Tail lights don’t work until warmed up?
if you get a temp gun you will see the area that is failing will be warmer
- 67D100Pickup
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Re: Tail lights don’t work until warmed up?
Front running lights work even when tail/tag lights don’t so the issue is clearly in the circuit after the split to front/rear wiring.PwrWgnDrvr wrote: ↑Tue Nov 28, 2023 11:15 amMaybe corrosion or crud on headlight switch terminals, connector, or internally. Do the front running lights do the same? If not, won't be the headlight switch. Also check firewall connectors for same.
Dang this sounds simple after you guys talk this out :-)
Jeff
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Re: Tail lights don’t work until warmed up?
Finally I had a chance to work on them when they were failing and confirmed that the problem was a loose firewall connector.PwrWgnDrvr wrote: ↑Tue Nov 28, 2023 11:15 amMaybe corrosion or crud on headlight switch terminals, connector, or internally. Do the front running lights do the same? If not, won't be the headlight switch. Also check firewall connectors for same.
Good job PwrWgnDrvr. Thank you for that tip!
Jeff
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