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Electric Fan Conversion

Did this swap last week on my 760 using a saab temp switch in the upper rad hose for low speed and the switch in the rad for high speed, works great so far, the real test will come in the AZ summer...
 
KwikBrik245 said:
Yup. I just picked up a 960 fan, 960 fan relay/harness, and a 2.4 940 ecu yesterday. Xmas Eve is the install date. I will just have to run two wires (low and high speed) from the ecu to the fan
Click to expand...


Which model of ECU is this that has the functionality?

I have an intermittent ECU problem so while I am solving that one, I could automate my e-fan operation.
 
OK, my turn:

Car: '88 240 DL NA
-Fan/shroud and attatched wiring to the relay: From a 960
-Relay and wiring/connector from relay to radiator
-Wiring from relay to battery
-Wiring from relay to driver's fender: From a 940

What else is needed before I start? Will the stock 240 alternator be good enough or should I take the alternator from the 940 at the yard? I drive in temperatures up to 110F in the summer, down to -10F in the winter.
 
Not sure which alternator I have, it's from a parts car.

Would the alternator from a '95 940 fit?

FCP Groton shows same part number for '87-'93 240 and '87-'91 740.

At the junkyard, there's an '87 740 and '95 940.
 
Your stock one will be good enough, but the '95 940's should be better. It may take some slight modification to work, but it should work. I put a 100A denso on my car a month or so ago, only mods were opening up the main positive terminal and splitting the insulation tube that contains the oil pressure switch wiring to allow it to come away from the positive terminal a bit farther. Nothing special, really.
 
bcumby said:
Which model of ECU is this that has the functionality?
Click to expand...

Still looking for this info - and it isn't as easy as "go find an lh 2.4 940 in a JY :lol:" - our JY's are fairly picked over and not many 9's - I will most likely have to buy the ECU with the on-board fan control from someone on TB.
 
klr142 said:
Your stock one will be good enough, but the '95 940's should be better. It may take some slight modification to work, but it should work. I put a 100A denso on my car a month or so ago, only mods were opening up the main positive terminal and splitting the insulation tube that contains the oil pressure switch wiring to allow it to come away from the positive terminal a bit farther. Nothing special, really.
Click to expand...

I was back at the yard and there were NO alternators left in the bricks....apparently they're pretty well sought after.

I just got to my parents' house and my dad happens to have a switch from a 740 radiator, we'll be checking if it works, the fan tested functional for both high and low speed.

I'm thinking of wiring the radiator switch to one speed and a toggle switch on my dash for the other....haven't decided whether I want high or low speed to be automatic though....I'm thinking low speed should come on automatically and high speed with the toggle? That way, I can give my charging system a break, by selecting between foglights, heater fan, and the engine fan.

Maybe I'll put LED bulbs in for my tail-lights and turn signals to save every little bit of power I can...I'll make sure the stock alternator is good enough. :lol:
 
Run the low speed off of it. You'll never need to use the high speed. Your stock alternator will be fine, mine was, but I wanted something better anyway, just for the peace of mind.
 
Done...all I had to do was snug 3 zip ties. :lol:

My dad did all the work while I took pictures of their house for the real estate ad. (It took me longer to prep rooms and shoot the pictures than it did for my dad to install the E-fan, new radiator, and fresh coolant.)

Anyway, a new radiator was needed because my stock radiator didn't have the hole for the temperature switch, and we figured it would be better to sell the stock radiator to someone that needed it than to attempt making a hole just the right size....low speed was wired to that switch, high speed was wrapped up and zip tied under the fan relay in case I deem low-speed insufficient. My voltmeter reads perfectly happy when the fan is on.

<a target="_blank" href="http://min.us/mvoQVeu#1"><img src="http://i.min.us/jesw3k.jpg" border="0"/></a>
Fan is from a '95 960
<a target="_blank" href="http://min.us/mvoQVeu#2"><img src="http://i.min.us/jexv3U.jpg" border="0"/></a>
Relay is from a '95 940
<a target="_blank" href="http://min.us/mvoQVeu#3"><img src="http://i.min.us/jexxCc.jpg" border="0"/></a>
Switch is from a '92 740

Radiator is brand new from Napa, for my '88 240, came with the hole for the switch. Tested on the stock 740 and that's what triggers the low speed.
 
Last edited:
Those pics are helpful!

So if I have that exact same setup right now, and am running my low speed to the temp sensor, how would I splice in a cabin-mounted switch that would activate the high speed fan?

Do I just take the high speed wire and put a switch on it then ground, like so?

volvorelay.jpg


Anybody wanna clarify this for me?
 
Xovaan said:
Those pics are helpful!

So if I have that exact same setup right now, and am running my low speed to the temp sensor, how would I splice in a cabin-mounted switch that would activate the high speed fan?

Do I just take the high speed wire and put a switch on it then ground, like so?

volvorelay.jpg


Anybody wanna clarify this for me?
Click to expand...

That's correct, the switch would just connect to ground whenever switched.
 
Thats funny, my 82 has that sensor in the radiator, but it was never plugged into anything. I had been wondering about that. I wonder if it works. I found a fan from a 740 at the junkyard, have to trim the shroud to make it work though..

so what turns the fan on for high speed? ac?
 
I'm trying to install a 740 elec. fan in my 780: not enough room; the fan/belt pulley touches the electric fan just by 1/4 of an inch. Would have thought it would be the same as a 740/760. :-(
 
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