Low speed fan problem..

[allomoto]

Hi guys,

I have a C2 with two rad.

One of the fans is not working on low speed, however it works on high speed.

I have read that there are four relays [Relays 19 and 21(low) and 20 and 22(high)] - where are these located?

I need to swap out relays and find out if it is a faulty relay or a fauly fan.

Thanks in advance.

J

[greerj1]

Hi guys,

I have a C2 with two rad.

One of the fans is not working on low speed, however it works on high speed.

I have read that there are four relays [Relays 19 and 21(low) and 20 and 22(high)] - where are these located?

I need to swap out relays and find out if it is a faulty relay or a fauly fan.

Thanks in advance.

J

I have the same problem and searched the forum to no avail. My manual says "see qualified technician for relays" and has no info on the layout/schematic of the relay holder. If the fan works on "high", I would think it the relay or the ballast resistor. I will be watching for a reply.

James

[allomoto]

I have the same problem and searched the forum to no avail. My manual says "see qualified technician for relays" and has no info on the layout/schematic of the relay holder. If the fan works on "high", I would think it the relay or the ballast resistor. I will be watching for a reply.

James

Hi James,

I have just located the relays, they sit under the dash (drivers side).

However not sure what relay does what.

And as you say it may well be the resistor, which I assume sits on the fan unit?

J

[greerj1]

I have the same problem and searched the forum to no avail. My manual says "see qualified technician for relays" and has no info on the layout/schematic of the relay holder. If the fan works on "high", I would think it the relay or the ballast resistor. I will be watching for a reply.

James

Hi James,

I have just located the relays, they sit under the dash (drivers side).

However not sure what relay does what.

And as you say it may well be the resistor, which I assume sits on the fan unit?

J

The resistor is mounted under the fan unit (one on each side), do a search for "ballast resistor" and you will find a thread with pictures showing the resistor location. I know where the relays are located, I don't know which relay corrosponds to the fan speeds either.

James

[1999Porsche911]

Relays #19 and 21 are for the stage 1 fans. To eliminate the relay as the cause, switch each stage 1 relay with stage 2's. Bottom row, further right and 3rd from right are for stage 2 and 2nd and 4th from right are stage 1.

[allomoto]

Thanks for the help, will try swapping out the relays tomorrow morning, if not will get the fan unit changed...

[Richard Hamilton]

J

It's MUCH more likely to be the ballast resistor, as that's what controls the low fan speed. There was a guy on PCGB with exactly the same problem.

[kabel]

If it is a similar set-up to the 986, I would consider the aforementioned resistor. I only just learned this. I didn't know the a/c fan had two speeds, my mechanic informed me that the low speed was not working because of a blown series resister, which he replaced. He said it is behind the front bumper somewhere, it was about 5 inches long and about .75" in diameter with two wires coming out of one end.

[Loren]

Right in front of each on the other side of the wheel well liner.