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Electric Fan Conversion

OldSchoolEuro said:
Won't turn on till it gets 75 percent to the hot zone
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I use an infrared temperature gun, like this, and shoot it at the thermostat housing, and top part of radiator near top hose...to verify.

My radiator temp sensor has a low set point, somewhere around 190 degrees, it switches "on." I wish set point was higher, since fan tends to cycle more in city traffic.

Unless you have verified your analog temp gauge inside of vehicle, I would assume nothing.

On GM vehicles, I don't think the fan comes on until like 225 degrees F, or so....its too high for my needs....this would pressurize your radiator system at that temp....and I don't like the thought of a freeze plug being persuaded to pop out...

I have no idea what Volvo specs are....was theirs setup to turn fan on at higher temps, like GM?
 
The kit I bought (temp sensor + wiring kit) turns on at 165F, which is roughly 2/3 on the temp. gauge. The fan usually turns on after I turn the car off, too. Once the fan kicks on doing about 65mph the gauge drops to 1/4.
 
Freq said:
(temp sensor + wiring kit) turns on at 165F, which is roughly 2/3 on the temp. gauge
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Seems quite low....unless you are running 160F thermostat....stock is around 197F...for a 1984 244...2.3 L...check specs in back of owner's manual.....that's about mid-way on temp gauge.

Fuel economy wise, and emission wise, I would suspect not being upto temperature would affect these two.
 
My thermostat is brand new. Yeah I have no idea what temp rating it is. I am thinking of wiring up a switch inside the car to turn on the fan just in case it doesnt. How would one go on and do that with my setup?
 
OldSchoolEuro said:
How would one go on and do that with my setup?
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Assuming the fan is a two speed motor, which it appears to be the case.

Circuit #22 - When engaged (ECU grounded), this engages fan, but prevents circuit #7 from engaging even if Circuit #7's is grounded at ECU.

Circuit #7 - When engaged (ECU grounded), the other Ciruit #22 will have an open at ECU, which feeds the hot juice to Circuit #7's relay.

In essence, only one side works at a time via ECU grounding....so, if your radiator's temp sensor is using the grounding principle on this relay, you can only do one relay (fan speed) at a time. Throwing two grounds at it, would only invoke Circuit #22.

So, your ground switch in interior needs to attach to Circuit # 22, and your radiator's temp sensor should be working on a grounding basis, and would hook to Circuit #7....

Are you using ground to activate relay...and running a hot link as shown in picture?

You can test this out, before you install your switch...simple grounds from battery...two of them, and touch circuit #7 first, then circuit #22. Circuit #22 over-rides circuit #7, as I read the schematic.

PS: This setup allows for high speed fan setup when you flip the switch....reverse wires for low speed fan when you switch it manually...your choice.
 
Yeah well there are three wires coming from the fan motor itself. (yeah its a 940 fan). Green, Red and Black wires. Green and Red wires go to the relay mentioned above. Black goes to a ground. Then there is the red wire that comes from the relay and goes to the battery with a inline use. Then there are two smaller wires that come from the relay. Yellow/Brown and Green/Orange. I took the green/orange wire out and just had the yellow/brown wire connected to the fan switch in the radiator. The other spade terminal on the fan switch is grounded. Thats how my setup is. I do NOT have the ECU that controls the e fan btw.

So I can only turn on the fan via the switch inside the car only on one speed?
 
OldSchoolEuro said:
Yellow/Brown and Green/Orange. I took the green/orange wire out and just had the yellow/brown wire connected to the fan switch in the radiator. The other spade terminal on the fan switch is grounded. ....So I can only turn on the fan via the switch inside the car only on one speed?
Click to expand...

It could be turned on on either speed, inside of vehicle, with a three-way switch, rocker type switch (On_1, Off, On_2)....Circuit #22 over-rides circuit #7, so when Circuit #22 is engaged, it should be the AC circuit, high fan speed.

The grounding on other spade terminal (Circuit #7) is a waste...fan should be running via C1-GRN wire...or internal relay has shot craps.
 
OldSchoolEuro said:
Oh yeah I forgot to mention I dont have AC in my 240. That's why theres a ground.
Click to expand...

That's why its backwards......its not needed...

Experiment:

1. Disconnect Spade Terminals at Relay Box (#22 & #7)

2. Get a grounded wire and touch each...what happens?

3. Get two grounded wires, and touch both...what happens?

Those terminals are normally activated via Ground Circuit via ECU...not needed now, if your Temp Sensor is grounded when switched on.
 
OldSchoolEuro said:
Does the ignition need to be turned on when I do these experiments?
Click to expand...

As based upon that schematic picture above, the Relay is wired Hot all the time....is this correct for your setup? Or did you put the Hot lead on a switched hot?

Disconnect wires 7 & 22.......at Relay....then ground a wire to battery ground (or frame), and touch the other end of this ground wire to Relay terminal 7 first, and then to relay terminal 22; the fan should run each time...with terminal 22 putting fan in high speed....is this the way it works on your setup now when this test is performed?
 
Yeah the relay has a red wire running straight into a inline fuse (40amp) to the battery so yeah it is wired hot all the time. So just ground each connection (7 and 22) and the fan should run each time i ground them?
 
Interesting topic

Now for my question. Since I will be using the turbo computers from my 1995 940t in my 1992 240, could I just rip the wires that run from the ECU to Efan relay from the 940? I could then just run those same wires on my 240 and plug one end up to the appropriate pin on the ecu and the other end on the relay. Pretty much the exact same setup as stock on my 940...

Eh?
 
OldSchoolEuro said:
just ground each connection (7 and 22 at Relay) and the fan should run each time i ground them?
Click to expand...

Correct....with the wiring harness removed (Yellow/Brown and Green/Orange wires at Relay), ground out each terminal separately with a ground lead....the fan should work each time the spade-terminals are grounded.
 
shellshock said:
Since I will be using the turbo computers from my 1995 940t in my 1992 240, could I just rip the wires that run from the ECU to Efan relay from the 940?
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I would assume you will be taking wiring harness out of 1995 anyway...correct.....if true, yes, you can use those wires from 1995 ECU....will need to convert to E-Fan, of course.


I would leave wiring harness intact when it is removed....your word "rip the wires" I don't understand.
 
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