RDS928S

Ok,
as luck would have it this morning the 928S fired right up on the first crank in 12 degree temps. But on the way to work and the car remained cold inside even after a 15 minute warm up period. I noticed the fan speed control **** for the climate control set on # 3 but no warm air blowing in. turned it to # 4 with no response?
Also tried engaging the AC pressure switch on the dash and the backlit light did not come on nor did the compressor?.

I checked the fuse chart and it refers to fuse #17 for "fresh air blower" and fuse #8 for the "AC".
Also the relay designated X is listed for the fresh air blower as well.

Are these two system related. I will be checking the fuses at lunch today.

Thanks RDS

heinrich

Was engine temp good? Coolant level? Maybe your heater lines froze in the car or at firewall. Also you apparently have a relay prob.

WallyP

You don't give the model year for your car, so we can't give specific answers...

The most likely cause is a bad blower relay. Swap the blower relay with another in the panel and see if the problem follows the relay.

RDS928S

Sorry Wally.

The car is a early 86 32v S model.
I checked the fuses they were good with a little corrosion on each one so I replaced them anyway. Still no fan or AC.

Is the blower relay the (X) designated unit?

Thanks Rich

RDS928S

Heinrich,

Yes coolant is good and the engine temp was good.
Just no response to the blower fan or AC pressure switch.

Rich

AO

Check your antifreeze. If you're not getting any heat, then either you're heater valve is stuck closed or your antifreeze... froze, which is a really really bad thing. I'd make sure you're protected to at least -20 or -40 depending on where you live. Also re-read Wally's post. He said to check the relay, not the fuse. Could also be a bad resistor pack.

RDS928S

Andrew thanks,

Heater valve is new and coolant is fresh.
I guess my first post was a little confusing the car starts up fine and gets to operating temp fine. A little heat comes out of the center dash vents and door armrest vents-but the fan does not work on the 1-4 position. Also the AC pressure on/off switch does not illuminate or engage the AC when depressed.

I'll replace the relay this afternoon. I have some spares.
What and where is the resistor pack?

Regards Rich

AO

What happens if you switch to the defrost setting? Does the fan come on full like it's supposed to?

RDS928S

Andrew,

yup- fan operates at full strength out the top dash vents when switched to defrost mode.

Rich

AO

Ok. Either a bad relay or bad resistor pack. Better hope it's the relay as the resistor pack is a major PITA I hear (knock on wood).

RDS928S

ok boy's fustration level is growing
Just got home and changed out the blower relay. No dice.
Andrew why is the resistor pack a PITA?
DR (928 Specialist) suggested checking the plug in connections in back of the climate control system.

Thanks Rich

AO

I guess I'd check the connections first, too. They are much easier to get at.

Here's a recentthread on resistor packs.
https://rennlist.com/forums/showthre...=resistor+pack

RDS928S

Andrew,

thanks for the thread.Good info.
I'am not looking forward to this job especialy in 20 degree weather.
Might have to pay the $90 plus per hour at the p-shop to fix it.

WallyP

The usual failure mode for the resistor pack is that you lose the lower three speeds, but speed 4 (highest) still works. High speed bypasses the resistor pack.

Look elsewhere - such as Dave's suggestion.

Could be a bad connection at the controller or at the resistor pack (which is different from a broken wire inside the resistor pack).

RDS928S

Wally,

good info. The fan does not work on position 4 so it must be something else.
This weekend I will remove the carpeted section next to the center console and inspect. Will post results.


Thanks to everyone for the methodical narrowing down of areas to inspect.


RDS