Does anyone know if there are different configurations on these , bought a new switch and the head lights work and outside running lights , inside running lights don't work and turn signal lights work but are blinking fast . Do I have to change configuration of pins on the connector ?
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Headlight Switch 1990 GMC c1500 Sierra
- Thread starter JSG
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Victor Rusk
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Hello. That's a common issue with these trucks. You're right to think that something is not right, as a new switch should not cause more problems. The fast blinking turn signals and the lack of interior running lights are not random issues; they are directly related to each other, and the problem is likely with the new switch itself.Does anyone know if there are different configurations on these , bought a new switch and the head lights work and outside running lights , inside running lights don't work and turn signal lights work but are blinking fast . Do I have to change configuration of pins on the connector ?
To answer your first question, yes, there are different wiring configurations for these switches, even within the same model year. The factory offered different trim levels and options, and the wiring harness could be different depending on whether the truck came with a convenience package or not.
The fast blinking turn signal is the key piece of information here. The flasher module in your truck is designed to detect an electrical load. It expects a certain amount of resistance from all the lights on the circuit. When a bulb burns out, the resistance changes, and the flasher module will blink faster to tell you that a bulb is out.1 In your case, the interior running lights are not working, so the flasher module thinks a bulb is out, and it's blinking faster as a result.
The problem is most likely that the new switch you bought is for a different configuration. It's not a matter of changing the pins on the connector. The connector itself is probably the same, but the internal wiring of the switch is different. It's not sending power to the circuit that controls the interior running lights.
What you should do is take the new switch back and compare it to the old one. Check the part number on both to see if they are the same. If they are not, you will need to get a new switch that is specifically for your vehicle's trim. It's a very common problem, and it's usually solved with the correct switch.