cooling fan problem

HELL DRIVER · 08:00 AM

i have an 84 944 the problem that i have is that the primary cooling fan is comming on to late. this is what the car is doing.
the primary fan only turns on untill the temp. gauge is on 3/4 not on the red yet. and when it turns on the both fans come on together. if i turn the ac on both fans turn on also, no matter what the temp is. now my ? is
is,nt the primary fan supposto turn on way before the car gets this hot? do you guys think that the slow speed register is bad?
if it is where is it located and what does it look like?

thank you, paul

bearone2 · 01-16-2005, 07:58 AM

do you have lo temp for the thermoswitch and thermostat.

my '84 turned the fans on just above the 1st line.

Britwrench · 01-16-2005, 08:51 AM

Has this just started happening or has it always been like this?
Does the thermostat work correctly?

Sounds like you have a higher temp fan switch installed.
If the fan cuts in where it does now, shuts off around at the middle of the guage, doesn't run too long, the car doesn't overheat, loose coolant and everything is working, then there's nothing wrong. You could put in a lower temp switch if you wanted. The fan low speed on early cars is only when you take the ignition key out and the engine temp is above a certain point
In general early cars have readings on the guage that is only a guide and is not necessarily accurate.

HELL DRIVER · 01-16-2005, 07:09 PM

I DONT RECALL THE CAR DOING THIS BEFORE. BUT, ITS NOT LIKE WE USED THE CAR MUCH. LAST YEAR WE REPLACED THE RADIATOR WITH A USED ONE. IT WAS CLEANED AND FLUSHED BUT I LEFT THE SAME TFS THAT CAME WITH THE USED RADIATOR.
SO. IAM JUST GOING TO BUY A LOW TFS AND SEE WHAT HAPPENS.

THIS ONLY HAPPENS WHEN THE CAR IS STANDING STILL AND THE ENGINE RUNNING. EVERYTHING ELSE SEEMS TO BE OK.

THANKS, PAUL

Porsche944 · 01-17-2005, 06:43 AM

What you are seeing is "normal."

With the early cars the fans are either on or off depending on the condition of the radiator temperature switch and/or the A/C.

With the ignition off and the radiator hot, the driver side fan will run for a short time at low speed. With the ignition on and the radiator hot, both fans run at high speed. With the ignition and A/C on, both fans run at high speed.

Later cars are similar to the early cars, but there are ome "refinements."

The first change is the radiator temp switch. On later models the switch has two setpoints, while the early cars have only one. The second change is the later cars have two modes when the A/C is running, the thrid change is to the fan relay, and the fourth change is later cars have fans with 6 blades, while early cars have fans with 3 blades. This last change was made to increase air flow and reduce fan noise.

With the ignition off and the radiator hot, both fans run for a short time at low speed. With the ignition on and the radiator hot, both fans run at low speed. When radiator temperature reaches the upper set point, both fans run at high speed.

With the ignition and A/C on, both fans run at low speed. When the A/C refrigerant temperature switch closes (refrigerant pressure is too high indicating too much load on the A/C system), both fans run at high speed.

Porsche-O-Phile · Porsche-O-Phile's Garage

Dude, TURN THE FREAKIN' CAPS LOCK OFF!!!

See how capitals make it look like I'm SHOUTING AT YOU? It's hugely annoying.