Well I finally jumped in and put the fan off of a '93 940T onto my '88 240. I cut the fan shroud down and rivited the end back on to make sure it sealed well against the radiator. Fan runs off of a relay which triggers through a SAAB inline temp sensor in the upper radiator hose, stock SAAB 110º unit was replaced with a 92ºC on 87ºC off sensor. It's been 90+ here so this was a good weekend to try it.

I started with a car that never had an overheating issue since getting a 3 row many years ago, the AC was cold at speed and very cool at idle. Still doesn't overheat but the AC is crap at idle, and not as good at speed. It turns out the belt driven fan provides quite a bit of air going over the condensor while you're sitting still and must have aided the flow at speed. As I was waiting for the car to warm up so I could make sure all was well I turned on the AC and after waiting for over 5 minutes with no cold air at all I thought I knocked something loose. Not true.

Now I could wire it so the low speed fan is on all the time when AC is on but the whole idea is to get rid of parasitic drag on the engine. Having a draw on the alternator is not much if any better than dragging a fan around. The cars that use this fan stock have a pressure switch on the condensor that turns the low speed on and off, 200s didn't get this 'till '92 when condensor fans became stock, if I remember right.

I rigged up a tattletale light to tell me when the fan is on, this part of the story is much better than the AC thing, the fan runs a bit when sitting for a while and after heavy acceleration at any speed. It also turns on for a while after the car is turned off. I hooked it up this way on purpose, if you don't want this feature just use a switched power source for the trigger voltage.

My only hope for this conversion is increased gas mileage, the engine revs better with no load, heck it's not dragging a 5 pound rotating mass around at the wrong end of a pully system. The fan is geared to turn faster than the engine speed, (smaller pulley on the water pump) so it takes a bit to spin it. Getting rid of this may or may not translate to more power to the road, it feels like it but after the pain in the butt and skinned knuckles installing this it may just be wishfull thinking. I did fill up and will check mileage.


Bottom line on this is I am not thrilled, the high setting has a strong enough power draw at startup to blow a 30A fuse once in a while, it will run forever through a 30a but start up is hit or miss. Makes sense as it is designed to switch from low to high, not start out at high. The low speed does fine for cooling however so all is good there.

My main fear is reliability, I would have jumped in this car and with noting more than a fluid change if due, driven anywhere in the country. Now with the added complexity on a critical system my faith is not there. A loose wire or blown fuse and you're dead in the water. I've overheated a red block, it's not pretty with those aliminum heads and all.

Will I keep it? Let's just say I'm not throwing away any parts yet. If I see 23mpg maybe, otherwise I know what I'll be doing next time I have some free time.
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Dave Shannon
Spring Valley, California
'67 1800s
'73 1800ES
'88-240
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