Troubleshooting a fan problem

daxdog · 11-05-2007, 04:26 AM

I need help. You guys always come through for me, so I'm coming here first.

My 1984 944 has been having a little difficulty keeping a constant temp. The temp guage will fluctuate between about 3/8 of the way up the guage to just above 1/2 way. I popped the hood in the Wal-Mart parking lot the other day when it was running warmer and I noticed that the passenger side fan was not running. The driver side fan was moving fine. I turned the passenger side fan a few inches by hand, but it was very stiff.

Before I go ordering a $200 fan from PelicanParts.com, is there something else I should check? Also, on a 10 point scale, how tough is this job? I think my skill level is around a 4 (but it is probably around a 1.5).

Thanks in advance,

George

earlr85944 · 11-05-2007, 05:15 AM

very easy job, you can do it. A good used will do for @ $50

daxdog · 11-05-2007, 07:46 AM

Is there any troubleshooting to do first?

Eldorado · 07:57 AM

I've done very few repairs myself, the rad fans being one of them. It's a very easy job - 6 bolts hold it on, 3 on top and 3 on bottom... the hardest part will be to find a screwdriver/socket able to reach the bolts because there's stuff in the way - but I did with a little work... remove neg cable from the battery, remove the 3 top bolts, then jack up the front of the car, remove the 3 bottom ones.. remove electrical connectors, and pull the fans out of the bottom of the car..... install is reverse of removal.

be sure not to get any drops of power steering fluid in your eyes from the 944's built-in automatic powersteering flushing system..

Before you replace them, check the voltage at the plug on the pass side fan. Should be 12 volts give or take.. do this by running the car with the AC on. If voltage checks out ok, then it's time to replace those fans. (I imagine, by what you've said, that this is the case).

HondaDustR · 08:55 AM

Or you could try WD40 on the bearings, which might fix it, at least for awhile.

I think you have to remove the airbox and front mounting bracket in order to get to the bolt on the top drivers side. Leave the AFM mounted to the airbox and just remove the two as a unit (just loosen the J boot clamp and disconnect the AFM signal connector). It's much quicker and easier. Just be sure to reconnect the AFM when you're done. I've found it to be an easy thing to forget, the car will barely run, you'll get a good "ohh ****, what's wrong now!!" reaction until you remember to plug it in, and life is good again.

Weird thing is, when I first got my car, only the driver side fan would run when the thermoswitch clicked on, but both would run when the A/C was turned on. Now both run any time the fans click on, and I didn't do anything to it.

bearone2 · 11-05-2007, 10:36 AM

wd40 is a dirt magnet.

3/8 to 1/2 is fine on the gage.

i replaced both 3bl fans/shroud with the 6bl setup and it was a boltin.
if you do it, check the fan clearance on the bottom rad hose.

drew1 · 11-08-2007, 12:45 AM

Yes, let's do some troubleshooting. Turn the AC on & see if both fans work.

drew1

Gordon Rankin · 04:39 AM

Daxdog??
Hey.. Having every conceivable problem possible with my 924 and 944 fans, the passenger side fan will not run unless your air conditioner is also turned on and running (air conditioner, not fans). Bearone and Drew are correct here.

With a car that has electrical fans and a thermal switch, your temp gauge should fluctuate since the fans are not constantly running. The fans only run at a preset temperature, cool the fluid and then turn off. Your sytem will and must
fluctuate.

But your passenger fan sounds kinda hinky. It should be easy to turn. But test out your air conditioning first.

Gordon Rankin · 04:32 AM

Also, if you need to pull your fans, you do NOT need to remove the Air Box, and bracket. ( Sorry Hondadstr)

You can move the top coolant hose aside after removing the plastic ties. You'll need to exert pressure against the hose to move it out of the way while you place the rachet wrench with an extender in to remove each of the 3 upper bolts. I think the socket should be 13mm. I use a 3inch extension on the uppers. The three bolts at the bottom are pretty easy to remove. My preference is to loosen the 3 bottom bolts first , remove the 2 corner bolts, before tackling the uppers.

earlr85944 · 11-08-2007, 06:26 AM

"the passenger side fan will not run unless your air conditioner is also turned on and running (air conditioner, not fans). "

That is not correct, check the wiring schematics.

earlr85944 · 11-08-2007, 06:48 AM

I took my own advice and checked the schematics, the early cars work as you say, the later cars have a 2 stage thermo switch which will run the 2nd fan after reaching a higher temp.

HondaDustR · 11-08-2007, 07:42 AM

Quote:

Also, if you need to pull your fans, you do NOT need to remove the Air Box, and bracket. ( Sorry Hondadstr)

You can move the top coolant hose aside after removing the plastic ties. You'll need to exert pressure against the hose to move it out of the way while you place the rachet wrench with an extender in to remove each of the 3 upper bolts. I think the socket should be 13mm. I use a 3inch extension on the uppers. The three bolts at the bottom are pretty easy to remove. My preference is to loosen the 3 bottom bolts first , remove the 2 corner bolts, before tackling the uppers.

Correction...they are actually 10mm bolts.

Gordon Rankin · 11-08-2007, 08:14 AM

Thanks for that clarification, Hondadustr..As i said before, I thought it was 13 mm.

Quote:

Originally Posted by HondaDustR

Correction...they are actually 10mm bolts.

earlr85944 · 11-08-2007, 02:05 PM

Gordon- what makes the fan shut after reaching the higher temp, I dont see this or have heard of it?

bearone2 · 11-08-2007, 02:18 PM

i've never heard of the fan shutting off after reaching the higher temp either.

HondaDustR · 07:53 PM

Quote:

Originally Posted by Gordon Rankin

Thanks for that clarification, Hondadustr..As i said before, I thought it was 13 mm.

hehe..just bring a 10, 12, and 13mm socket, and you be ready for just about anything on these cars. Not exactly, but it does seem to be true 90% of the time!

I wonder if there's a way to rewire the early fans to work on a 2 stage thermoswitch. I have been concerned at times sitting in traffic on a hot day and having the head temp drop so abruptly so often.