86 Spider overheating up hills: pusher A/C fan?

[Brad Karp <bkarp@domain.elided>]

Many thanks to the several generous souls who responded to my earlier note, 
inquiring about my 86 Spider Quad's overheating while going uphill.

Suggestions included:

	- thermostat
		*** I should have mentioned that it was replaced when the
		    engine was rebuilt in the summer of 2000--sorry.  ***
	- bypass restrictor in hose from heater (hmmm, still need to check this)
	- mixing coolant/oil (head gasket?)
		*** No problem here; no discernible mixing, and again, the
		    whole engine was rebuilt, with new cylinder head and new
		    head gasket, in summer of 2000. ***
	- pusher fan in front of AC condenser
		*** possible eureka, read on... ***

(Again, the radiator was refurbished and the water pump is new.)

The last suggestion, the pusher fan in front of the AC condenser, seems promising.

This morning, I turned on the AC (I hardly ever use it here in the beautiful Berkeley weather)--fan to max, cooling to max. The compressor came on, and cool air came out of the interior vents. (I had the belt replaced and system charged by Monza when they did the engine rebuild in the summer of 2000.)

But the pusher fan in front of the AC condenser did not come on! So I assume it also fails to come on when the temperature sensor on the radiator fan cowling should trigger it (to help with cooling when conditions are causing the engine to run hot).

Two questions for the list, now:

	1) Is it certain that the pusher fan should be on whenever the
	   compressor is on? (I think it should, but just making sure.)

	2) When I'm driving uphill for a few miles in hot (>90 F) conditions,
	   AC turned off, would not having the pusher fan helping airflow to
	   the radiator make a big enough difference to cause the car to
	   overheat?

	   I presume that having the AC condenser in front of the radiator
	   makes the radiator less efficient, and the temperature sensor to
	   trigger the AC fan would not have been added by the factory if it
	   weren't really necessary, but I suspect people on the list may have
	   concrete experience with how much of a difference the pusher fan
	   makes for engine cooling when the AC is off.

Many thanks again,
-Brad, bkarp@domain.elided
86 Spider Quadrifoglio, daily driver

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