Hey guys. New to this forum. I’m on many others.
Corvette Forum
Square Body Forum
Ect.

My grandpa has a 1998 K-2500 Silverado
He got a steel on the truck that you wouldn’t believe. It’s got a unique pinstripe on it. At one point it was used to haul something, with a gooseneck. Came from Eastern Washington, I think they hauled horses with it because the pinstripe detail and rims on it. Musta been some cow girls truck. That’s my guess. It’s geared down a lot with a heavy duty trans in it. About 2k rpm at 55mph without a trailer. We use it for hauling my project vehicles and as a work truck and other stuff. You guys wouldn’t believe how good shape this truck is inside and out. Hardly a scratch on it. It’s time we diagnose the electrical problems it has.

Starting off, It has a problem with the gas gauge going nuts back and forth, empty, full repeatedly. It has a new fuel pump in it. Thinking it’s the gauge motor?

Next problem is the Fan. If you don’t drive the truck for a few days the blower motor doesn’t work. But when you drive it for a few days it kicks in. It turns itself too high, then low. Repeatedly. Doesn’t matter what position the switch is in. After a while it just stays on full. Thinking it’s the resistor?

Next one, the radio center console doesn’t light up when the Running lights turn on. All the other lights work.

The wipers sometimes keep running when they get shut off. Or if you just put them on low they go full blast.

The hazard lights don’t work, when you flip the blinker on it doesn’t work, but the dash just shows the blinker indicators both on steady. Then you gotta mess with the hazards button to get the blinkers to work.

Also the lumbar support doesn’t work on the drivers seat.

I believe that’s all? I’m not sure. Thanks I’m advance!

 

-Did you replace the complete pump and hanger assembly or just the pump, leaving the original sending unit in place?

It’s possible the gas gauge stepper motor is having problems - the clusters are known to have problems. Before condemning it, disconnect the fuel pump/sending unit connector at the tank and turn the key on - observe the gauge for erratic movement and whether it’s pegged at empty or full.

Then, at the fuel pump connector, jumper the black/white and blue wire together and observe the gauge again. It should be pegged to the opposite side of the gauge and steady.

-Is the blower motor noisy? What you describe is a weak electrical connection, but it will require further inspection to determine if it’s the wiring, resistor or motor (or combination thereof).

-Remove the radio and check for power on the purple/white wire with the key on and sweeping the dimmer switch through the full range of rotation, including turning on the dome light. If voltage is present at all times, the issue is in the radio (not sure if it has a bulb to be replaced or not).

-Replace the windshield wiper pulse board (or wiper motor assembly). They cause erratic operation when they go bad. Make sure to clean the connector contacts.

-It’s likely the turn/hazard switch needs replacement but it would be cheaper and easier to replace the flashing unit first - either one could cause the issue you describe. If you open the column to replace the switch, check for battery voltage at the Orange and pink wires with the key on and verify they will light an incandescent test light.

-The seat switch receives battery power from the circuit breaker in the cabin fuse block. If everything but the lumbar support is working, either the switch or the lumbar motor is faulty. You’ll have to remove the switch and try to trace the wires that run to the lumbar motor, then check for power/ground while operating the switch.