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Efan swap help

Wesdunns70t5m

New member
Joined
Oct 4, 2016
Location
Jacksonville, NC
So today I picked up an electric fan, wiring, and relays from a 97 960. Ive measured the shroud and marked where to cut to make it fit, but I?m clueless on the wiring. Some places say you can use the temp sensor in the radiator, others say that a different sensor is needed. Can someone draw me up a simple wiring diagram or something of the sort? I?d like to free up some engine bay room and some horses by doing this conversion. Thanks in advancsd
 
volvo_relay_diagram.PNG


When I do the swap, I'll be just connecting the battery to the relay with an inline 30A fuse, have the temp sensor on the rad hose set up for high speed, and the low speed will be a 12V switch inside the car that I turn on or off whenever I want.
 
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I did this on mine a long time ago, but I had Megasquirt to use as a programmable output.

The fan control relay has 12V+ and ground going to it, and there are two 'control' wires. These are grounded to turn the fan on. One for 'low' speed, one for 'high'.

My car was a late model 240, so it had a pusher fan (that I removed as part of this mod) that came on when the A/C was on (and hot, I think it was hooked to a pressure switch in the system, not merely on when the compressor was on). I kept that system in place, and added an MS output to that, to control the 'low' speed setting. In MS I set the 'on' temp about 5 degrees hotter than the thermostat temp, so in normal use with the car moving, the fan wouldn't come on at all. There's no reason to run it at the thermostat temp, it will just run constantly.

The temp sensor in the radiator was set (from the factory?) to a rather uncomfortably hot temp - it came on at something like 220 degrees. I used that to engage 'high' speed on the fan, as a 'dumb' failsafe. Just ran a wire from the relay 'high' terminal to one side of the switch, and a wire from the other side to a ground.

On the low speed circuit, MS already was set up to ground a circuit to engage the fan, so I just connected the wire up to the relay. But the existing pusher fan circuit switched on 12V+ to engage the fan, so I just used a cube relay there.

'Control' circuit:
pusher fan circuit 12V+ --> relay terminal 86 --> relay terminal 85 (although really, 85 or 86 are interchangeable) --> ground
'Main'
low speed relay wire --> relay terminal 30 --> relay terminal 87 --> ground

That turned a 'hot is on' pusher fan signal to a 'ground is on' cooling fan signal.
 
Lol, I wonder if I was using the temp sensor wrong on mine. Eh, it worked. The two terminals connected at around 220 degrees.
 
Just did this yesterday to my 240. It definitely opens up some room and I'll take any freed up power that i can get! Very easy to wire up, and i hate wiring!
 
Don't the Volvo relays have a internal breaker? Also what ECU do you have? If it's lh2.4 just wire it to the ECU and get a efan compatible ECU from a 9 series
 
I?ve checked my ecu number and unfortunately I won?t be able to control the fan from the ecu

The approach I?m gonna take is I ordered one of these:
https://www.amazon.com/Kangnice-Tem...or+adapter&dpPl=1&dpID=411t16HPiiL&ref=plSrch

This will be placed in the upper radiator hose. I?m gonna drill the hole out and tap it to accept the sensor from a bmw. The sensor has two part numbers, one for an 80/88 degree sensor, and the other for 91/99. This will be used to control both fan speeds. I?m sure I could?ve done this whole thing cheaper, but this is about the easiest way I?ve found to automatically control the fans.

I?ll post up with the results/anymore questions. One part I ordered won?t arrive until mid-late December, so stay tuned!
 
Damn, can’t believe I missed that in the first post. Lh2.4 1990 760 wagon. I’ve already deleted the ac components, along with the front condenser fan which was locked up anyway. I daily the car, but plan on making some pretty good power coming soon. I’m still acquiring some parts for the 19t install. Just gotta save up for the exhaust parts, and oil return. I’m mainly doing the fan conversion for engine bay room, and noise levels. I don’t expect a huge gain with the electric fan honestly. Once I get the mechanical fan in my hands it may be heavier than I expect and may change my mind though
 
I've noticed a difference, engine seems to rev a bit easier. If nothing else you remove all that weight from the end of your water pump.
 
Damn, can?t believe I missed that in the first post. Lh2.4 1990 760 wagon. I?ve already deleted the ac components, along with the front condenser fan which was locked up anyway. I daily the car, but plan on making some pretty good power coming soon. I?m still acquiring some parts for the 19t install. Just gotta save up for the exhaust parts, and oil return. I?m mainly doing the fan conversion for engine bay room, and noise levels. I don?t expect a huge gain with the electric fan honestly. Once I get the mechanical fan in my hands it may be heavier than I expect and may change my mind though

It's lh2.4 you can just swap to a later model ECU. It's nice having it ECU controlled. Because you know they like did that from the factory..
 
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