p_tothe_g

Hey All,
Lost my "low" speed fans. High speed still work. but only when the temp goes a bit high (not quite in the red, but close to). And the fans no longer run after the engine is shut off "hot".

Pretty certain I am looking at a failed "low speed resistor". Problem is, I can't find it/them. One post I read said they were under the dash on the passenger side. I do not believe this is the case with an S2. Only things under there are the ABS module, the Airbag module and some assorted wiring harnesses.

Does anyone know the location of these on an S2??

Thanks

Van

I imagine they're in the same place as on a turbo.










Oh, you want to know where that is? Take off the rubber molding above the fire wall in the engine compartment. Lift up the front of the plastic cover that covers the blower box (this is the piece that's covers whatever is between the battery and the fuse box). A little offset to the driver's side, you'll see a plug that goes to the "resistor pack module". The module is held on with 2 bolts.

fbgh2o

Have you tested the relay to make that is working properly. Clark's Garage has an excellent article on troubleshooting the fans.

I do not know the S2, but the resistor pucks are deep in the passenger footwell on the Turbo. You have to remove the glove box liner to see them. They mounted on the underside of the battery tray - two greyish white ceramic pucks with a buch of wires connected to them. You literally have lie on your back in the footwell to remove them - careful there seem to be a fair number of metallic edges that results in small cuts and scrapes.



Van, I think you are talking about the blower... not the fans.

p_tothe_g

hey Guys,

Van-- I'll take a peak there at lunch, brought my meter to work so I can check and order asap if indeed that is the problem. Just want to confirm that we are talking about the radiator fan resistors and not the HVAC blower motor??

Fergus--I did check Clark's page, and the trouble shooting guide pretty much points to a failed resistor, because the high speed fans DO kick on when called for, but no dice for low speed. Both fans do work, so I do not suspect the relay, just no slow speed, so I am leaning towards the $20 resistor vs. the $160 relay. Just need to find them so I can do a rsistance check, infinity=bad.

I have read a previous post about the resistors being in the passenger side foot well, I have taken out the glove box and contorted my 6'3" body up in there so I can look around. there is nothing there except the ABS module (on kickpanel side), the Airbag module (mounted up, just under the battery tray), a few wire harnesses, and the duct work for the vents, NO DICE on any resistors in that area. If they are in that area, they may be hidden under the sound insulation rubber that is laying against the wheel house part of the body, but I didn't see anything there either. I also removed the panel where the DME resides, and nothing but the DME lives there.

If anyone else has some info, it would be cool (no pun intented) to get this solved asap. I really do not want to pull the head off yet, have a DE event in a few weeks.

Thanks for the input

Spidey944

You talking about the engine fans?? Or the interior fans?? The engine fans run off the temp switches, not resistors. The interior fans use the resistors.

p_tothe_g

I am completely confused now. I've lost low speed cooling fan (a la RADIATOR), nothing to do with HVAC system. Clark's page and the Porsche wire diagram (and PTEP) all show resistors in the circuit for the cooling fans, in PTEP they are on the same page as the radiator fans themselfs (item 7). The fan relay is a 4 pole single throw relay, when the first part is tripped it sends power thru the resistors therefore a slow speed, when the second set is tripped it sends opposing voltage to the resistors and full voltage to the fans, thus high speed. At least that is my understanding looking at the information I have. And people sell the darn resistors as "Cooling fan" resistors, not "blower motor" resistors, plus there are 4 speeds to the blower motor, why only 2 resistors?

Please can somebody confirm that I am not crazy and that there are indeed resistors in the "COOLING FAN" circuit. And if so, please could somebody confirm where they are on an S2--- for certain.

Thanks for the input everybody, I am sure I'll get to the bottom of this soon.
-pg

Spidey944

wow, just printed my diagram, and there ARE resistors, I guess I never paid that much attention to them! Maybe it's a late car thing.... Let me do some research, BRB.

Spidey944

OK, looking at the diagram, you should be able to jump F22 and O33 to bypass the resistor and make the low speed fan come on. Although thinking about it, without the resistor there, you should get high speed opperation of Fan 1. I hate electrical work! It's easy to talk yourself into circles. F22 and O33 may be listed as V1 or TS on the fuse panel, I'm not in front of my car to check.

I searched through all of my diagrams and component locators and there is no location for the resistors anywhere. I will keep digging until someone chimes in.

Any way you can find a lister in the area to swap relays for a test?

p_tothe_g

thanks a bunch for diggin around Doug, I am pretty sure that the relay is functioning properly I can feel it click at around the temp the "low" speed should come on, but no fans. this is part the reason (along with Clark's trouble shoot guide) why I am targeting the resistors.

But I do see what you are saying. If BOTH low speed fans do not work, is it possible that BOTH my resistors blew at the same time? probably not. But if I could find the little bastards it would be a quick check, infinity = bad resistor, and no BS pinning out the fuse box and crappy electrical diagnostics.

ALL POINTS BULLETIN IN BURLINGTON VT AREA, ANYONE WHO CAN LEND ME THIER "KNOWN GOOD" COOLANT FAN RELAY FOR APPROX 10 MINUTES WILL GET A FREE LUNCH (or a 1/2 tank of gas for getting here)!!!!

p_tothe_g

FOUND THE RESISTORS!!!!

different location than Van stated, but certainly close. Just to the passenger side of the HVAC blower motor assembly, mounted to bulkhead/firewall, just under the lip of the windshield.

Pretty certain these are the ones I need. CHECKED for resistance on both and viola! .OFL on both.

Thanks everybody for your help!!!

bearone

if it's about 4 ", white, held down by two screws with a pretty good sized connector, it's for the blower motor, not the fans.

i only have hi-speed on my fans when the temp gets up and/or a/c is on.

87951
95sl320 dd

Van

Glad you found them!

p_tothe_g

thanks Van, for leading me to the right area. I am kicking myself in the pants for listening to the 8V guys post where they have thiers up behind the glove box, now my dash is in pieces

Bearone-the 4-pack for the HVAC blower is mounted just to the passenger side of the cruise control module on an S2 (probably same for a turbo).

Again to everybody, thanks for the responses, helped me nail a potential bad problem before something happened (should probably do a leak down test for insurance on the head gasket).

you all ROCK!
-pg

fbgh2o

Sorry about the misdirect. I have rebuilt them on both my '86 n/a and '86 turbo. In both cases it was wires that had cooked..

bearone

nope, on the turbo it's under the shield just below the windshield, just as you described in post # 10.

87951
95sl320 dd