Jlbarnett

So I'm having an odd error. And yes I used the search button. Every time I wash the 993 (with a garden hose, no pressure washer) The Broken Fan Belt Warning light comes on. It will stay on for maybe a day or less. Usually I will go for a long drive and get it hot, then on restart the light is gone.

I check the belt every time just to be sure. The belt, sensor, and little plastic wheel look fine and there is no water in the connector, although the connector does have some play in it.

Curiously, I decided to only wash my wheels last week. Same thing happened though. Warning light came on, then went off after getting the engine hot and restarting it. I'm assuming there is a short somewhere, but how would water in the wheel wells affect the sensor that is in the middle of the engine bay?

The warning light has never come on unless the car gets wet, which is only during a wash.

I'm resigned to the fact that the sensor will need replacing unless someone has an ideas? PN#?

*Update

Replaced the fan belt sensor with a new one and a new mounting bolt and the problem still persists. But only when I wash the car. After the car gets warm and dries out the light stays off all the time. There has got to be something up with the wiring somewhere causing a short when it gets wet. Ironically the few times I have driven in the rain the light does NOT come on.

jscott82

To confirm the issue is the sensor, unplug the sensor and jump the two terminals.

The bearings are known to disintegrate and not push the arm all the way in.

993.106.035.00

nine9six

Check as recommended ^^^.

Probably water entering wiring or sensor and shorting; once things dry out, you have normal operation again. It is a good idea to check the sensor wheel from time to time, for normal operation.

OverBoosted28

When I did my RS fan hub install, I removed and disassembled the sensor. Cleaned and lubed (dielectric grease) all contacts. After assuring roller assm. was still fine, I went and found TINY bolts, washers and nylock nut. Reassembled and install. Should last forever. Now that I've said that I will have it fail :-)
And yes, I know I don't need it any longer, but I still kept it. If it fails, then I'll chuck it.

Jlbarnett

Thank you. Excuse my electrical ignorance, but what exactly is jumping the terminals?

Vorsicht

It means to connect the two terminals with a wire.

Edit: Just to be clear, you are jumping the two terminals on the side going to the car. IIRC, once jumped the light should go out. If it does, you have isolated the issue to the sensor.

Jlbarnett

*Update

Replaced the fan belt sensor with a new one and a new mounting bolt and the problem still persists; but only when I wash the car. After the car gets warm and dries out the light stays off all the time. There has got to be something up with the wiring somewhere causing a short when it gets wet. Ironically the few times I have driven in the rain the light does NOT come on.

Raleigh993

Have you checked your grounds?

I have seen a lot of electrical gremlins traced back to deteriorating ground connections particularly when water is involved. Good luck.

hn

When the warning light is on, turn off the engine and remove the plug. Test continuity between the terminals of the sensor. If there is no continuity , the problem is on the sensor's side, if there is, the problem is on the other side, may be the plug just needs some cleaning at the contacts.

I don't know if it was coincident but mine happened when it was raining, too. I did the check as I mentioned above and found no continuity on the sensor. I did as what Chris suggested: remove the sensor and take it a part. bend the metal lever that connected between the arm and the micro switch so that at when installed, the arm pushes the switch in a little more. Make sure the one end of the lever which rests on the arm still curve down so it won't cause too much friction on the arm and might prevent the arm from springing back in case the belt does break.

Just to share what I did to fix mine. You have a new sensor so I can't tell it this procedure will help.

good luck

nine9six

I agree with your assessment.
Water is getting into the wiring via the engine bay; maybe at a plug terminal? ...And shorting, causing a sensor light illumination. Apparently rain water, which is significantly less than the garden hose on the louvered portion of the engine bay, is not enough to cause the short.

Starting at the sensor with the car running, try using a spray bottle of water, and spray each component/terminal, on back to the plug terminal; while checking each location after spraying, to see which causes the light. Do this while keeping water out of and away from the alternator/fan/distributor cap areas.
(Let the flaming begin for this ^ suggestion...)

Yes, there are electronic methods of checking this, but per your own admission of being electronically challenged; I am trying to put the methodology into words so you can understand the logic of tracing back and isolating the problem location.

Hope this helps...

Jlbarnett

This actually sounds like a good idea. I can deal with mechanical problems but I have no clue about electricity or electrical gremlins.

Jlbarnett

Do you have any links to show where all the grounds are located?

BTW where are you located in Raleigh? I have seen a black 993 riding around Northeast Raleigh a few times, your car?

Raleigh993

JL,

Here is a good thread that should help you check out the ground points.

https://rennlist.com/forums/993-foru...s-located.html

I would offer my electrical diagnostic expertise, but I have none.

I live in N Raleigh near 6Forks & 540. I try to get the car out at least once a week and have a short route on 540 that takes me over to 401 and back so that could be me.

Do you do the PCA gatherings at Brier Creek?

Chip

Jlbarnett

Thanks for the link, didn't know 993's had so many ground straps lol

I live in Rolesville so it was probably you I saw on 401

I made it out to the PCA monthly meeting tonight at mellow mushroom in Cary and had a great time, haven't been out to Brier Creek Coffee on Saturday mornings yet.

Jarrett

Raleigh993

I also buy my ethanol free gas at Ernie's on Mitchell Mill Rd.