I'm new to the site and could use some help with this: The right side dash indicator lights on my 90 F150 5.0L 4WD XLT Lariat are all out, but the turn signal/flashers and 4WD work fine. It was like this when I got the truck. I checked all the fuses and removed the instrument cluster and replaced all the bulbs and they're still out. The underdash wiring looks clean and the instrument cluster did not appear to have ever been removed. Could this be a bad connection or ground? Thanks for any advice.

 

I believe most of those lights are normally applied + power when the ignition is switched on, and they're grounded to turn them on. I'd start by checking to see if the bulbs have +12v on one side of them with the key on.

 

Short in the headlight switch maybe?

 

You may have an open in the headlight switch. The bulbs are always grounded and power is supplied by the headlight switch and not the ignition.
Fuse #4 or #10 may also be open.
Also turn the headlight **** to see if they come on.






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Subford, I think he's talking about actual indicators, like check engine, etc..., not dashboard illumination?

 

But he said that he replaced all the bulbs and that the 4X4 lamp works.
The 4X4 lamp gets its power from the smae place as the check engine.


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The same thing with my headlight **** is starting. If I don't pull it out fully and then twist to the right, my dash lights won't come on but my headlights will.

 

The actual indicators are out, not the instrument panel illumination. All 4 bulbs on the right side are out: anti-lock indicator, 4X4 indicator, 4X4 Low Range indicator, and RH Turn indicator. They just don't come on. The brakes work fine, the 4WD is engaging in both high and low range, and the RH turn signal exterior lamps work too. All the indicators on the left side of the dash, check engine, LH Turn signal, etc, work fine. The cluster diagram shows separate wiring to the left side and right side indicators from the fuse block, so that may explain why only the right side could be out. I noticed the previous owner did do some wiring under the dash, tapping the fuse block, and could have screwed something up. Real PITA.

 

So no power to C250 pin #13.
A red wire with a yellow stripe, wire #640.



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Well, that narrows it down. Thanks, Subford.