Fans and thermo switch or Relay-whats at fault here

[iamchappy]

My problem is the fans switch on normally when the engine heats up but shut off completely when the ignition is turned off. If i turn the ignition switch back on the fans run again and shut off after a minute or so when they get things cooled down.

Would this be in the relay or the thermo switch.
Is the relay not transmitting or bypassing power to the fans when the ignition switch is turned off.

Also i want to put a cooler thermostat in, the PO had a high temp one put in last winter.
Our host sells thermostats but does not list any temp ranges. Where should i look to buy one.

[hpservertech]

Have you tried to jumper it to see if it will run at both speeds yet?

There is a write up on clarks for this.

[John_AZ]

Chappy,

Your thermofan switch may be bad due to internal burnout or contact arcing. The stock fan switch is 87-92C. PP has it. For MN this is probably the best. Cheap to replace. Watch the threads on the plastic radiator side. They strip easy. The fix is JB Weld on threads.

I use the low fan switch 77-82C. AZ is Hot.

To test the AC relay. With car off, turn key to on and turn on AC. Both fans should be on. Relay OK. If passenger fan off, Buy a new relay $40 or try a DIY fix. Ask if needed.

Thermostat. 80C is stock and 70C is low. Again in MN I would use stock.

GL
John_AZ

[iamchappy]

Ok, i ordered the stock Thermo-that fits the turbo water pump from our host, and picked up a new Thermo Fan switch today at the Porsche dealership. If that dont work next stop relay.......

The 944 tech guy at Porsche recommended to me Bilge Pump Cleaner found at your local West Marine store to flush the radiator.....

[John_AZ]

P.S.

Just so you do not do a beginner mistake



Snap ring--shim for turbo style pump--outer gasket (either 4.5mm or 2.5 mm depending on pump-NAPA)
Gasket slips around T-Stat.

Inner seal (don't bother with it this time unless it has rotted and cracked--eyeball if you can get your head between the radiator-fans presumably have been taken out---and the opening.

John_AZ

[mattdavis11]

There are two relays for the fans on the 924s and the early car. A/C relay and the a/c fan (condenser fans) relay are on the passengers side, it is not relay #3, the cooling fan relay is located above the fuse block and is #1.

[John_AZ]

Originally Posted by John_AZ

To test the AC relay. With car off, turn key to on and turn on AC. Both fans should be on. Relay OK. If passenger fan off, Buy a new relay $40 or try a DIY fix. Ask if needed. John_AZ

Matt is correct. I should have said "Cooling fan Relay" and not AC relay. My test for the "Cooling fan relay" is OK. The cooling fan relay is #1 on panel.

Thanks Matt.

John_AZ

[mattdavis11]

Sure thing.

I like to chime in every chance I get to point out that the relays are not as labeled in all the manuals. Relay #3 is most definately not the air conditioner relay, but it is the fresh air fan relay.

[iamchappy]

Originally Posted by John_AZ

P.S.

Just so you do not do a beginner mistake



Inner seal (don't bother with it this time unless it has rotted and cracked--eyeball if you can get your head between the radiator-fans presumably have been taken out---and the opening.

John_AZ

Oh Oh, I purchased the inner seal also, I always replace this stuff while I'm in there.
What i didn't do is examine the new seal before trying to hook out the old.
to my surprise it is a metal rubber covered pressed in seal ( John your dont bother wasn't enough information for me, I needed to know why not to bother, but if i had followed your suggestion i wouldn't be stuck right now ), i was able to get the all the rubber off of it but i am going to have a hell of a time getting the metal sleeve out of there. My option would be to use some RTV or make a rubber o ring. i think the only way to remove the inner seal would be to dremel tool it out.

Anyone got any ideas.......

[John_AZ]

I have 2 inner seals sitting in my toolbox. I read how hard it was to replace with the pump in and did not continue. AllData.com may have a TSB. I checked the WSM and did not find any reference. You may get help if you PM HondaDustR. He has had recent experience with the inner seal and might have a suggestion. See post #3.
installing thermostad

Good Luck,
John_AZ

[iamchappy]

Thanks John, I will keep you posted on how i solve this puzzle.....

Oh by the way, i have finally got the 914 out for a few break in drives, this car is very
very scary, and i have been taking it easy so far.

[iamchappy]

I choose not to try any further means of getting this out after several hours of screwing around.

I didn't want to grind in there with the dremel, so i made a rubber washer out of red gasket material and put some red HT RTV on both sides to insure a good seal. I cant see any reason that this wont work, unless the bottom of the thermostat also needs to move in and out..... This is generally not the way i do things but that stainless steel band inside the rubber seal would not distort while prying at it with a flat tip screw driver, and a mini nail puller bar. I was able to exert plenty of force on both.

[John_AZ]

From WSM.


The new "top" gasket has to let the thermostat function correctly.

John_AZ

[iamchappy]

I dont get it. I did put the thermostat into boiling water but only the radiator side opened the side shown in A moving 7m didn't move at all. So it was also suppose to open, if so, i guess everything is coming apart again and the Dremel tool will have to go into service after all.

[iamchappy]

Ok i did another test on a thermostat. Measurement A is the distance it grows, not opens. I do question that my make shift o-ring will work as it was design to seal and chances are it will work itself free.
Thank God i have the Snap on snap wring tool as removing it again will go easy but i still will have to dig that inner seal out there bummer...

[John_AZ]

Originally Posted by iamchappy

Thanks John, I will keep you posted on how i solve this puzzle.....

Oh by the way, i have finally got the 914 out for a few break in drives, this car is very
very scary, and i have been taking it easy so far.

I had to read more of your 914-6 Turbo post and look in awe of the pictures of the turbo.

http://www.914world.com/bbs2/index.php?showtopic=75381



Very nice.
John_AZ

[iamchappy]

Ok this is the easy and painless way to remove the inner seal.
Purchase a 1 inch internal pipe wrench found in the plumbing section of your local hardware or builders store for about ten bucks. The one i purchased had to have about 1/2 inch ground off the end to allow the expanding cam to grip it but i have seen others that look like they would work straight out of the box. Only a few twists and it was out! I cant stress the usefulness of the Snap On snap ring tool easy in easy out.

[John_AZ]

Time to celebrate!

John_AZ

[iamchappy]

Here it is...