electric fan on a 240 ?

hertfordnc · Post by **hertfordnc** » 10 Oct 2006, 08:30

Just because I can....

The local junkyard has a few 740's with electric fans. Is there any value in converting my 89 240?

dave

brucepick · Post by **brucepick** » 11 Oct 2006, 10:13

hertfordnc wrote:....The local junkyard has a few 740's with electric fans. Is there any value in converting my 89 240?...dave

Yes there's value in converting (I did).
But I can't promise that a 740 fan is the thing to use.

From what I've seen the fans in 740s are small pushers, little fans in front of the rad + AC concenser that actually are there to assist the AC system. Not big enough to replace the clutch-driven fan for the cooling system.

I used a behind-the-radiator fan from a 960 (had broken timing belt). This fan is a strong one. 850s, I believe, have the same fan. 940s have the same but maybe only a one-speed version, the 960 fan I used has 2 speeds. Whatever fan you get, take the whole wire harness for it also. Mine came with the OEM relay, plus 2 groundable trip leads (high + low speeds), fan ground and main hot wire with fusible link built into it. Took longer to pull from the junker, but well worth it.

I'm convinced the engine has an easier job if it no longer has to spin the mechanical clutch fan all the time.

Harvest temp switch holders from the upper hose of Saabs, mid-80's to mid-90's. Get a new switch, on at about 75-80 deg. C, off at 5 degrees cooler than the on temp. The Saab holders take a commonly used thread size; lots of VWs and other euro cars used them. Hose size matches the 240 hose.

If you're handy enough with electrical work, you can wire the fan relay to run low speed when your foot is on the brake. That's how mine is and I love it. Preventative cooling exactly when it's needed. Temp switch is also there; comes on in heavy traffic etc.