Electrical Gremlins with Sensors and Headlights

Electrical Gremlins & Sensors – Between the ABS, HVAC system, the Motronic Ignition, the Immobilizer system, and others there are a lot of switches and sensors with their attendant connectors in a 993. Seeing that these cars are 25+ years old now with many having 100K+ miles on them sorting out electrical issues in many cases has more to do with cleaning faulty connections versus replacing a failed component. For this reason, I always clean any device connector before I go the next step in diagnosing the device as the source of a problem.

I personally have run across this with the Idle Control Valve and the ABS Wheel rotation sensors. Many times the device can be tested at its connector with a basic volt Ohm meter. In fact, the easily sourced 993 wiring diagrams, many times, lists the value one should see on the meter right next to the device on the drawing.

Headlight issues:

If your car has the original factory headlights or your headlights have been upgraded with aftermarket High-Intensity Discharge (HID) sometimes called Xenon lamps and you find you have intermittent problems where the low beams, high beams, or both won't always illuminate here is the quick fix before looking any deeper into the problem. 

Unlock and slide the headlight pods out, check the pods' electrical plugs and sockets for condition, that none of the pins are bent and the individual pin sockets look good. Then flush them both out with spray electronic cleaner. Once cleaned put a little silicone or Teflon spray lube on a fingertip and rub it on the electrical plug seals. Then spray a little on the headlight mounting rails. Reinstall the headlight pods making sure they are firmly & fully seated. 

For HID Lamps:

If you have now over twenty-five-year-old factory original HID headlamps that continue to have intermittent problems lighting off this can also be caused by dust and dirt accumulation on the lamp envelopes causing a partial grounding condition so cleaning the bulbs with some spray cleaner too may resolve this issue for some. If you have HID lamps that simply won't ever light off consider replacing the entire ballast and lamp assemblies with aftermarket kits. Here is a page that discusses this.

#OBD #OBDC #OBDC-II #On board diagnostic #headlamps #pods #HID #Halogen