dash indecator lights for 4-hi, 4-low,and cruise

[buzz_mn_58]

Hi all, My dash indecator lights quit working for 4-hi, 4-low and the cruise contol. They all quit at the same time. They are all next to each other, on the right side of the dash. It still goes into 4 hi and low and cruise works just no lights. I pulled and checked all fuses, all were good. Can Anybody help me with my problem ? Thanks, Buzz
2000 XLT 4X4
4-door
flareside
75,000 miles

 

[Harris]

Since the cruise and 4 High, 4 Low indicator lights would get their supplies from different places it sounds like they may have shared a ground that failed. It's unlikely that all three supply circuits broke at once. I would bet they shared a ground.

You could check that by pulling the instrument cluster forward and testing for voltage from the hot side of the light to a known ground, or just use your alligator clips and go from the ground side to a known ground and see if the light comes on. Of course you will have to have the key on and the transfer case in 4 High or 4 Low. It's hard to tell without being able to look at it.

 

[buzz_mn_58]

Harris....... I think you were right. The lights are working know, I did nothing.
My wife drives this truck 3 miles down a wash board dirt road
every day. It had to be a ground problem. Thanks

 

[Harris]

Well...I hope they stay on, but intermittent problems can be the bane of any do-it-yourself technician. It sounds like all that rattling has jarred the end of the ground loose and right now it is touching the metal enough for the lights to function. It may be fine for many years, but I would not bet on it. Like I said, though, hopefully it will stay functional.

 

[Earl43P]

I beg to differ (sorry Harris).

Those 3 lights all get their power directly from the headlights switch.

Their grounds are different (GEM for the 4x4, Speed control servo for the cruise).

Whenever it happens again (if ever), you can verify that the headlight switch is the problem by turning off your Overdrive. It is the 4th of 4 lights that share power from the headlights switch. So, if the Overdrive lamp goes out with the other 3 = bad headlight switch.

FWIW, there have been many reported cases where the headlamp switch overheats and actually melts the insulation on the wires going to it.