mobird

Ok so my 79 has a weird issue with the interior gauge backlights. When I'm driving at night, obviously I pull the headlight **** to make the headlights pop up, this also turns on the gauge backlights. However I can only have either my speedometer and tach illuminated (by turning the headlight **** to the left) or my center gauges like temp, oil pressure, fuel, etc... illuminated (by turning the headlight **** to the right).


I take it that isn't normal? haha.


It's kind of a pain because I find myself spinning the **** left and right to keep an eye on my temp and oil pressure and also my speed.

Easy Mike

No. Not normal. All the gauges should illuminate when parking or headlights are on.

Drifter36

Hi
I’m having a similar problem with my headlight switch as well on my 82. Except my lights are very dim. Before I change it out, I’m going to check the instrument panel ground connection G101. Also, there’s a grounding lead from the headlight switch to this ground point. It’s available from Zip so I’ll probably replace it as well. Good luck.
Btw
The ground connection is just above the driver kick panel

Peterbuilt

Good a place to start as any.
Here's a picture.

san

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The previous pic is for pre 78....different on a 79.
I would suspect the light switxh is deffective somehow....

san

This is from a 78...hope it helps!!
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