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Gentlemen,

A friend of mine has a 1989 944 Turbo that is having some cooling issues. I have the following questions:

1) How many cooling fans are there?

2) Are they all electric, or is there an engine-driven fan? (I'm a 911 guy so only know from engine-driven fans)

3) How are the fans turned on and off?

4) What major components (wires, resistors) are present in the fan control circuits?

5) Are there common failure points? Do the fan relays fail, for example with the same frequency as a DME relay?

Also, my friend is having difficulty with a high NOX level. I believe this is due to high combustion temperatures. Could this also be caused by a defect with the cooling system?

Thanks in advance for helping an aircooled brother help another watercooled guy.