roman944

ok, so here's some more info:

I checked the # on the thermo-fan switch, and its 75* - and I am pretty sure that this is the part I got form Pelican Parts

so my new theory would be, that somehow, MAYBE, the thermostat I have is the "high-temp" one? but without taking it out and looking at it, there is no way to tell

if it is a high-temp one, something like a 90* one, and thermostat tells fans when to start, and it always starts at the 3rd mark on the gauge ... then maybe I just need to get a low-temp thermostat?

I think I have one of those multi-purpose relays, BUT, its like 1/2 the size of the original relay, is it still safe to use?

and, if I get a low-temp thermostat, is there any way to change it without taking out the waterpump out of the car again?

thanks guys!

smokin_944

Understand one thing Roman, the A/C relay is a tall looking unit #944 615 113 01. The cooling fan relay is a short 1/2 size unit, #141 951 253 B. You DO NOT need to take the WP out to change stats!!!!

roman944

cooling fan relay is the #1 relay on the panel, and its the same size as a DME

this multi-purpose relay is 1/2 the size of the #1 relay on the panel (which, looking at Clark's, is the fan relay?)

how do I change the thermostat w/o taking out the WP?

CorsePerVita

I changed my stat with the pump in the car. It requires being a contortionist and somehow managing to twist your body in such ways that it shouldn't do. But it can be done. You must take the red pill, bend a spoon with your mind and then you will be ready.

(in all seriousness though, a really good set of snapring pliers, being REALLY patient and careful and you can do it with the pump in the car, but it IS awkward and you'll probably use a few expletives in the process).

It is possible that if the stat is taking for freaking ever to open that things may not be kicking on till the stat opens since the driver side fan goes off the thermo switch in the radiator if it's a high temp stat.

A more likely culprit is the infamous evil bubble lurking behind the stat that won't go away. (if this be the case and you DO end up checking the stat, us the 1/8" hole trick i mentioned earlier)

Do you have anything saying which stat you put in? If the lower rad hose is COLD stat isn't open. if it's warm/hot STAT IS OPEN.

Did you buy an OEM thermostat, or did you just get one from a parts store? I had an issue with a "generic fit" stat from Napa that was the right temp but the diameter of the opening hole was significantly smaller, causing flow issues and i was consistently running at the 3rd mark rather than 1/2 or less.

roman944

this thermostat came with the waterpump kit from Rennbay, maybe Travis can give more info, because their website does not mention what kind of thermostat comes with the kit ... I think he mentioned before that the only option is the low-temp one, but I am not sure

it's weird that the thermostat waits exactly until the 3rd bar on the gauge before the fans kick in

and, after cleaning the connectors etc both fans started working now, but they don't keep working after I shut the car off, I have to leave the key in the "on" position right before "start"

smokin_944

The bad news is to change the thermostat you have to remove the lower rad hose where the therm resides... meaning you have to bleed the cooling system again after the switch...from one thermostat to another. If you read the part number on the #1 relay you may be in for a surprise... Look at the realy in the number 3 position and tell me what the number is... I'll be waiting for your answer...

smokin_944

Roman, the fans kicking on at the third bar are directly related to the thermal fan switch which controls them, nothing to do with the stat...This means you probably have a high value thermal fan switch, 92/87. The other thing is because you have a Series 1 car like mine, the primary fan should remain on at slow speed until the temp is lowered to the predetermined value of the switch, even with the key out of the ignition.

CorsePerVita

I think what he means is, regardless of the actual temperature of the thermal switch, if the thermostat didn't open till the temperature hits 3/4 of the bar (185-190ish or higher) then the temp in the rad won't hit that till that fluid hits the rad and turns the fan on. Normal operation a stat would open at a normal temperature stat opens the thermal switch isn't the same temp, so even though the stat is open, the switch wouldn't kick on till the coolant reaches those temps. But till the thermostat opens, all the coolant in the radiator is going to remain the same since it isn't going to be going anywhere.

smokin_944

Ahhh, I see what you mean... My thermal fan switch turns on the primary fan before the stat opens (71 C). In other words, my slow speed fan is already running before the Tstat opens. I did this before I understood how the cooling system was designed. My system overcools in that on a 20 degree C day, I never actually reach 80 degrees C of operating temp. However, the temp sensor of the gauge marks the temp correctly regardless of when the Tstat opens... I may run a video tomorrow to demonstrate what I am saying. When you have a high temp thermal fan switch installed in your car and you shut the car off, the primary fan should run til you hit the lowest temp value of the switch. In the case of a high temp switch, the fan sholud stop at the lowest value stamped on the switch. On a 92/87 switch, I believe the primary fan would shut off at 87 degrees C, even if the car isn't running.

roman944

BUT my thermo-fan switch is 70/75 ... and I don't know what my thermostat is

so you are describing a low-stat and high thermo fan switch situation

for me, it might be low thermo-fan switch and high thermostat

smokin_944

If your thermal fan switch is a 75/70 (823.959.481)the primary fan should come on in slow speed mode at 75 degrees C, that is to say before the first hash mark on your gauge. If it doesn't, it is faulty or the temp gauge is inaccurate. If you have a high temp Tstat, both fans should be going at high speed before it opens. That is providing both parts are functionning correctly.

roman944

my fans come on together and only once the thermostat opens, they don't turn on when I turn the A/C ****, they also don't stay on once I turn the car off, they shut off with the car

also, think I should have mentioned this earlier - but my car has A/C delete (including behind the dash)

what would you suggest I do now?

951Saga

Short the fans on when the gauge shows half way, if the temp continues to rise to the third mark, then the stat is not opening when it should.

roman944

think I missed this ... my driver's fan does not run on low speed

when fans kick on, they both kick on at high speed

and temp stays around the 3rd mark

they turn off with the car when I turn the car off; they don't turn on when I turn the A/C **** (maybe because the A/C and everything related - including whatever plugs were behind the dash)

smokin_944

Driver side does not kick on at slow speed = problem with resistor/bad slow speed fan resistor. Find it, replace it. That should fix that problem.
If you have A/C delete, then the A/C switch probably doesn't do anything anymore. The PO probably wired up the system in his own way... All troubleshooting from that point on is guesswork. Nonetheless, if you want the fans to come on earlier, swap your faulty 75/70 thermofan switch (yes it is faulty if the fans only come on at 97 degrees C) or test it as per Clark's garage.