[Axtman]

I have a 2002 Chevy S10 LS, manual transmission, manual door locks/windows. Over a year ago the warning lights would come on a off and sometimes blink or stay on for no reason. For example the seat belt light would come on even though I have my seat belt on. The Service 4WD light would come on even though the truck does not have four wheel drive. The battery, ABS, security. low fuel, etc. lights would come on even though there is nothing wrong with them.

I checked all fuses (under the hood and near the driver's side door) and did not find a problem.

Sometimes when I hit the top of the dash they go out. Lately the lights have stayed on eve when I turn the engine off and exited the truck. I have come out to find the battery dead. I have pulled the fuse to the radio. That turns the lights off but also the radio (duh) and also the fuel level indicator.

Any help would be appreciated. Thanks.

 

[oldeerslayer]

Has the radio been upgraded from original? By who? Does it have an aftermarket security system installed?

 

[Axtman]

Everything on the truck is stock. No new radio or other modifications.

 

[Usagoal]

Do you only have one fuse for the radio or two? Which one did you pull? I'm trying to dig up a schematic showing the warning lights and how they are related to the fuse you removed. You whack the top of the dash and the lights go out...so I'm guessing you may have a broken/damaged wire going to the instrument panel. You can pull the panel and do the old wiggle test to find the general area the wire is damaged. I have an 01 automatic so I'm not sure if the fuse configuration is the same.

 

[Axtman]

The fuse is #19 upper left-hand corner "RDO BATT" 15A.

 

[Usagoal]

This diagram is from an 01. Fuse #19 also powers the instrument panel. I'm not sure exactly what it is powering (still looking into that) but my guess is still a wire that is losing it's connection to the plug on the back of the instrument panel. I would pull the instrument panel out and start pulling/moving wires around. Starting with the orange (A10 on diagram) and also the grounds. It could be at the connector as well. You can have the panel pulled and the vehicle running (or key in run position) and watch it as you move/test wires to see if the warning lights flash or stay on.

I had a similar issue awhile back with dash lights turning on/off, gauges not working, etc...so I dove into the harness going to the panel and methodically found a single broken wire. There are some other diagrams that may help and I will try to find them. Connector pinout especially. Let us know how you make out if you decide to pull the panel and test.

 

[PeteD]

This diagram is from an 01. Fuse #19 also powers the instrument panel. I'm not sure exactly what it is powering (still looking into that) but my guess is still a wire that is losing it's connection to the plug on the back of the instrument panel. I would pull the instrument panel out and start pulling/moving wires around. Starting with the orange (A10 on diagram) and also the grounds. It could be at the connector as well. You can have the panel pulled and the vehicle running (or key in run position) and watch it as you move/test wires to see if the warning lights flash or stay on.

I had a similar issue awhile back with dash lights turning on/off, gauges not working, etc...so I dove into the harness going to the panel and methodically found a single broken wire. There are some other diagrams that may help and I will try to find them. Connector pinout especially. Let us know how you make out if you decide to pull the panel and test.

View attachment 371591

Dash / inst. Panel grounds corroded ?
Re establish briefly when dash is wacked

 

[Axtman]

Thanks for the suggestions!

I would think a loss of ground would turn the warning lights OFF and not ON.

The picture below is while the engine is running and I am driving (I pulled over to take the picture.)

Could it possibly be an ignition switch issue? That said I do not have problems starting the engine.

Also, I do NOT have problems with illuminated dash lights, headlights, taillights, turn signal lights, brake lights, rear-view mirror lights or interior courtesy lights.

 

[PeteD]

Thanks for the suggestions!

I would think a loss of ground would turn the warning lights OFF and not ON.

The picture below is while the engine is running and I am driving (I pulled over to take the picture.)

Could it possibly be an ignition switch issue? That said I do not have problems starting the engine.

Also, I do NOT have problems with illuminated dash lights, headlights, taillights, turn signal lights, brake lights, rear-view mirror lights or interior courtesy lights.

View attachment 371596

Your surmise basically true. Electricity will 'seek alternative' ground paths , occasionally creating seemingly illogically results

 

[Usagoal]

Lately the lights have stayed on eve when I turn the engine off and exited the truck. I have come out to find the battery dead. I have pulled the fuse to the radio. That turns the lights off but also the radio (duh) and also the fuel level indicator.

Do the indicator lights stay off when the fuse is pulled AND the engine running? In the previous diagram there are several power sources, though I'm not sure if the different sources power the indicators at different modes (key on, key off, engine running, etc). All of this seems to go through what is labeled as "logic". This tells me there is an integrated circuit routing power and ground for the indicators.

Through another diagram (1st pic) I was looking at, the warning lights seem to be turned on by ground (from the PCM serial data line) and powered by IGN power (I think). Second pic is the instrument panel connector diagram. I'm still hung up on the fact that if you bang the top of the dash the indicators go out. Do they stay off for awhile, or do they come back almost immediately? Banging on the dash is basically sending a vibration through a localized area behind the instrument panel (and surrounding wires), momentarily making the connection again - like a broken wire reconnecting. That's the theory I'm going with at the moment. If it wasn't for the Will Smith dashboard slap I would go in a different direction. I will keep digging into the radio fuse info...

 

[Axtman]

Yes the lights remain off when I pull the fuse and the engine is running. I have been driving around with the fuse out. The only downside is I have no radio and the fuel indicator is always on "E" even though I have a full tank of gas.

Banging on the dash sometimes turns the offending warning lights off. Sometimes they stay off but inevitably they come back on when I am driving.

Last week the warning lights must have stayed on when I exited the truck. The next day I came out to a dead battery.

What about an issue with the ignition switch? When the truck is started all the warning lights come on briefly then go out (in a correctly operating vehicle).

 

[Usagoal]

I suppose it's possible...but to be sure you would have to test the switch with a meter. There are other wires that need to be tested to determine what the next step is. Here is the connector and partial diagrams for the ignition switch. I forget if the connector is behind the lower column cover or the lower dash (knee) cover?? Focus on the wires with the red arrow next to them. With the key in the "lock" position and removed, you should not have voltage on any of those wires. If you wanted to rule out the switch this is where to start. I would then try pulling the instrument panel to test wires and connectors back there.

I don't know if the instrument panel itself would be bad..other than a cold/broken solder joint at the connector header. Let us know if you test and find anything.

 

[davidgirod]

im having the same issue on my 03 zr2. i have replaced the key harness and it didnt help. i dont hit the dash but might try that to see if it helps.

 

[oldeerslayer]

Usually either faulty ignition switch feeding bulb check circuit or a faulty cluster that is feeding back to the test circuit.