Just take some wire and connect the leads on the fan switch. This completes the circuit, simulating the switch being activated. Word of caution: your battery will drain if you leave it jumpered, the driver's side fan will run in low speed mode (hard to hear unless you're right up there and looking for it).

 

Contrary to popular belief, a lack of thermostat INCREASES temperatures. More flow, temps go up, less flow temps go down. For effociency you want that coolant moving slowly through the radiator and the thermostat contributes to that.

 

I stand corrected.

Austin, try pulling your AC relay and seeing if anything changes. If nothing changes, replace it, it's bad. There's probably a way to test the relay using a multimeter and a voltage source, not sure off the top of my head.

...or you could just do an AC delete, it's overrated

 

not in Florida ! ahahhahaha.

btw,

when you do an AC delete it ALWAYS keep the AC relay so you run the high speed fans manually by flipping the AC switch.

 

My fan switch is good. It's brand new 2 weeks ago. It is my fan switch sensor that's in question. I was asking how I jump that , if possible..

 

If my AC relay is bad,....how come my AC works perfectly?
you lost me on this ....
....

 

not true, not supported by measured data on my cars of several brands. It is also not supported by thermodynamics and heat transfer analysis, this is just an old wife's tale.

you can read about liquid/air heat exchanger theory here: http://www.wlv.com/products/databook...ata/db3ch6.pdf
show me any equation, anywhere in that paper that predicts improved heat transfer when you reduce the flow rate.

if you have measurements please post them and provide the source. If you want to run a test, measure temperature after 1 hour of driving with the thermostat removed. Then install and repeat and see what you see.

 

Interesting, must be differing opinions, I read it in Greg Sloans 944 V8 conversion book, he quotes from http://www.stewartcomponents.com/Tech_Tips.htm

No practical experience so I will bow to yours.

 

I am experiencing the exact same problem with my 86 944. There is a procedure at Clark's Garage to test the fan relay. But I dont know for sure if it also applies to the 924. My fan relay tested good. Which had me breathing a sigh of relief since that relay cost around $200 new. So that leaves me with having to replace the Thermofan switch. Some of the threads I researched say that the thermostat and switch need to be matched for the same temps. I have a new set, but havent installed it yet.

 

Hoping Wednesday to take a drive down to Miami and pick up a new fan relay. Part # 141951253B

Will swap that out and hope it is the fix. If not, I probably make an appointment with recommended Porsche tech indy in Ft. Lauderdale to have him look over the fans issue & my sometimes coolant odor coming in to the cabin when I use my AC.

Thanks, and will report progress.

 

look at it this way - the heat transfer is proportional to temperature difference (to some power, depends on heat transfer method). if you imagine the two extremes - very slow circulation from a nearly closed thermostat, and very fast circulation with no thermostat, you will see immediately that the slower circulation lets the water sit in the radiator longer, so it comes back cooler, but that it sits in the engine and gets hotter too. Because the water in the radiator is cooler, there is less heat transfer.

Another way to look at this is that if removing the thermostat (which is like having it super duper open) didn't cause the engine to run cooler, installing a thermostat would not help the engine warm up on a cold day.

There is a lot of mythology that is not supported by facts and data. Just because someone makes a claim, it doesn't follow that the claim is correct, or that their proposed mechanization is correct - however you can test these claims with real or thought experiments - for example the one I propose above where you think about why installing a thermostat which is closed when the engine is cold allows the car to warm up faster than no thermostat, and then you compare that analysis to the claim that no thermostat makes the car run hotter.

And, you should take my claims with a grain of salt too - think through what I claim, what the other claims and determine based on your own reasoning which one is valid. If you can, run your own experiment.

 

So, back to my most likely bad fan relay: Is there any easy way to remove this Fan Relay? I cannot even move it at all. It is a tight fit to start in upper left hand corner with the secondary fuse panel in front / below it and the fan relay is then snug against the carpet body of the footwell. I can barely fit 2 fingers on each side & then pulling it won't move.

....

 

Went to Mike Gokey in Ft. Lauderdale at German Performance for 1st time & got things fixed. ( Thanks Mike in Palm Beach) Simple fix for fans was installing a thermostat & my fans work now when they should . He also did a pressure test and that was good as well. Very impressed and when needed I will go back.

Also they fixed my dash light gauges which kept blowing the fuse . Removed cluster and one blown bulb in the fuel gauge cluster was blown and once this was replaced everything is perfect.