Low Speed Fans Question

[dr_karlb]

Loren (and all),

after completing the coolant tank R&R this weekend, i let the car idle up to temperature.

I never heard the low speed fans come on at all, but when the gauge got just into the 0 in 180, the high speed ones kicked in. I put the AC on and Off to see if there was a speed change, but it felt and sounded the same (AC runs fast seepd right ?)

Q: I read there was a fuse for the low speed that blows after getting wet by driving thru puddle sometimes. Where can i find that fuse (and do you have a Part number ?)

Anything else to check ?

Thanks

[Loren]

The radiator fan fuses are C8 and C10.

I doubt they would run at all with the fuse blown.

I wonder if you have a bad fan ballast?

Where are you located?

[1999Porsche911]

The fans do not go into high speed just beause the A/C is on. It must also meet the engine temperature requirement. So get the engine hotter and try it.

You might also switch the low and high speed fan relays to see if there is a problem with one of them. Relays 19 and 21(low) and 20 and 22(high).

Edited November 6, 2006 by 1999Porsche911

[dr_karlb]

The radiator fan fuses are C8 and C10.

I doubt they would run at all with the fuse blown.

I wonder if you have a bad fan ballast?

Where are you located?

I work in Santa Clara and Live in Mtn View.

I thought the AC kicked the fans into high speed no matter what the engine temp ??

I dont think ive ever had them run at low speed...

In stop and go the engine temp will creep up and if i hit the AC it stabilizes again.

After the coolant tank change i got the chance to just let the car get all the way to temperature and the fast speed kicked in, but never saw the low speed.

Where is the fan ballast and how can i test this. Im an engineer so have access to some tools and im quite handy :-)

Thanks

[dr_karlb]

The fans do not go into high speed just beause the A/C is on. It must also meet the engine temperature requirement. So get the engine hotter and try it.

You might also switch the low and high speed fan relays to see if there is a problem with one of them. Relays 19 and 21(low) and 20 and 22(high).

Just ran to the parking lot and tried this.

Car hasnt been driven for 7 hours so is cold.

No fans if i just run the engine. Hit the AC and the fans come on fast in a feew seconds.

There are relays for each side ? Neither low speed works and both hi speeds work.

Is there a layout for the relays ?

Thanks

[Loren]

I am in Morgan Hill (just South of San Jose).

If you want I can hook up my PST2 and we can test both fans and both speeds. PM me if you want to do this.

[1999Porsche911]

When your coolant temperature is below around 200F (don't have the exact temp at my finger tips) turning the A/C on will only turn on the LOW SPEED FANS. If your high speed fans come on, something is wrong. If you have never heard the high speed fans, you might mistaken the low speed for high speed. However, when the high speed is on, you will definately know.

Test the high speed fan by grounding the appropriate fan relay and you'll hear what high speed sounds like.

Edited November 7, 2006 by 1999Porsche911

[elias1000]

The fan ballast is your problem I just replaced mine last weekend each radiator fan takes an individual fan ballast and they cost about $120.00 Ea.

I had the same problem the fans would only turn on high speed.

[eurotrashed]

Are the fans ever supposed to stay on for a certain amount of time after you shut the car off?

Edited November 7, 2006 by eurotrashed