Dashboard light question

[papa1930]

Hey all.

Just had some work done on my '96 XLT which included replacing odometer (think he just replaced whole section (from junkyard). Anyway, just picked it up yesterday. Everything (gauges) seemed to be working fine, but then it got dusk, and I turned my headlights on and they worked, but the dashboard light did not come on.

From what I can tell everything works fine except for 2 things. The dashboard light is not working, and the overhead light dimmer switch also doesn't work. I can turn the overhead light on from the overhead switch and it works, just not the dimmer switch on dash.


I pulled the fuse box, and checked no.7 fuse, and it looks ok, though I haven't used a multimeter yet. Am I checking the right one? It's a 7.5 amp fuse labeled "illum. switch" in the owners manual. Is there anything else that could make just those 2 things not work?

I want to check everything I can myself before I take it back.


Thanks in advance.

 

[koda2000]

if he replace the cluster with one from the junk yard, he should have replaced, at least, the 6 cluster illumination bulbs and tested the rest to make sure they all worked. i'd just take it back and let him fix it. if it's the bulbs i'd be willing to pay for new ones, but not the labor.

 

[papa1930]

Thanks for replying koda.

I don't know if it's just the bulbs. The dimmer switch on the dash for the overhead light is not working either, but the light itself works from the overhead console switch, just not the dash switch.

Plus my temperature gauge is maxing as soon I start driving down the road. Radiator is full, and I don't think it could heat up immediately anyway (although I am in Houston - lol)).

Maybe the cluster is bad. I don't know.

 

[03 Explorer XLT]

The dimmer switch probably got unplugged, or a wire broke. Normally if it's turned all the way down the dash lights will go out.

 

[RockyMtnHigh]

The individual driver and passenger lights that are controlled by the "lamp" switches in the overhead console are independent of the "courtesy" light that is also located in the overhead console. There are 3 separate bulbs under the clear cover. The "courtesy" light (front, passenger, cargo) turns on when the doors are open or the dash dimmer switch is set to the full "on" position. Likewise, when the dimmer switch is turned to full "off" the dash lights do not operate. The "courtesy" light will also not operate even with the doors open when the switch is set to the "off" position. I suspect that the dimmer switch (located next to the headlight switch) is in the off position or is disconnected.

 

[papa1930]

Thanks for replying RMH.

Took it back, and he replaced the cluster with a different one, and all the lights are working fine now. It was a bad cluster.


However the temperature gauge problem is still present. As soon as I start driving down the road the temp. gauge goes up to redline in seconds. Mechanic said it must be the "sending unit" that's the problem because the cluster(s) were both out of 97's, and I have a '96. He's supposed to get one(sending unit) out of a '97, and hook it up for me in a few days. Don't know if it's a thermostat sending unit, or a radiator sending unit or what that connects to the temp gauge.

Anyone ever heard of the temp. gauge sending unit being different from a '96 to a '97?

 

[bobflood]

Thanks for replying RMH.

Took it back, and he replaced the cluster with a different one, and all the lights are working fine now. It was a bad cluster.


However the temperature gauge problem is still present. As soon as I start driving down the road the temp. gauge goes up to redline in seconds. Mechanic said it must be the "sending unit" that's the problem because the cluster(s) were both out of 97's, and I have a '96. He's supposed to get one(sending unit) out of a '97, and hook it up for me in a few days. Don't know if it's a thermostat sending unit, or a radiator sending unit or what that connects to the temp gauge.

Anyone ever heard of the temp. gauge sending unit being different from a '96 to a '97?

Hard to believe they are different, but stranger things have happened. If your temp gauge is pinning Hot as soon as you turn on the ignition, then the circuit is being grounded somewhere. The sending unit is nothing more than a variable resistor between ground and the gauge that changes value with temperature. It could be grounded thru the sending unit (that is in fact the most likely) or somewhere along the wire to the cluster. It is a single red/white wire; the sending unit is usually in/near the thermostat housing. There willl be two temp sensors - one with a single wire for the gauge and one with two wire for the ECU. Good luck.

 

[papa1930]

Thanks for replying Bob.

If your temp gauge is pinning Hot as soon as you turn on the ignition, then the circuit is being grounded somewhere.

It could be grounded thru the sending unit (that is in fact the most likely) or somewhere along the wire to the cluster. It is a single red/white wire; the sending unit is usually in/near the thermostat housing. There willl be two temp sensors - one with a single wire for the gauge and one with two wire for the ECU.

It doesn't redline immediately, but within a minute or so of driving it's maxed out. Plenty of water and the engine doesn't seem to be running hot. The mechanic is 15 miles away, and I've drove there twice since the problem began.

Funny you should mention the ECU. One of the things I had done was to replace it (expensive little sucker) because OBD was giving both front O2 sensors, and ecu codes.