Electric Fan Conversion

[iHateVolvoPeople]

Originally Posted by photoman327

I had a 940 fan and modified it and now that I think on it a little if was a 740 turbo that had the shoe shroud. I have a couple of the 240 off set turbo shrouds that will work but more bulk. Plan to take a look and see i Like it with a electric fan. I could mount a electric fan in the same way.

The 240 turbo shrouds allow you to have an intercooler and a mechanical fan with shroud, right? I was really tempted to buy the correct shroud and replace my fan clutch on the +t car. The reliability of a mechanical fan clutch is amazing..as well as how much air it moves at higher RPM's.

I could use a mechanical fan with the intercooler but couldn't get the stock shroud to fit in there, so I went e fan.

[photoman327]

Originally Posted by 93Volvo240

The 240 turbo shrouds allow you to have an intercooler and a mechanical fan with shroud, right? I was really tempted to buy the correct shroud and replace my fan clutch on the +t car. The reliability of a mechanical fan clutch is amazing..as well as how much air it moves at higher RPM's.

I could use a mechanical fan with the intercooler but couldn't get the stock shroud to fit in there, so I went e fan.

just came in form cutting part of the back yard and will putting stuff away realized I have been a buying Fool. got two of the offset shrouds i got from Dave Barton and another short one I could mount electric fan. Think I will use it but the one of the offset one if you can use it let me know. it will be cheap. I had not issue with the tropical clutch fan, may have ran a little cooler. I change because of the noise and though it may have had a bump in mileage. I did not see a increase in MPG although other claimed too. i theory its the way to go but since that failure i'm always thinking it might go bad again.

[iHateVolvoPeople]

Originally Posted by photoman327

just came in form cutting part of the back yard and will putting stuff away realized I have been a buying Fool. got two of the offset shrouds i got from Dave Barton and another short one I could mount electric fan. Think I will use it but the one of the offset one if you can use it let me know. it will be cheap. I had not issue with the tropical clutch fan, may have ran a little cooler. I change because of the noise and though it may have had a bump in mileage. I did not see a increase in MPG although other claimed too. i theory its the way to go but since that failure i'm always thinking it might go bad again.

I beleive mechanical fans move more air (in general) and are much more reliable.

That being said, my e-fan setup is 'complete' with the high speed on a switch. It has no issues keeping the car cool, but the idle bogs down when I switch it on (which is to be expected I guess). I need to wire up my controller for the low speed setting.

My hacked 940 shroud seems to do just fine.

[84B23F]

Originally Posted by 93Volvo240

I beleive mechanical fans move more air (in general).

If running hilly/mountainous terrain mostly, its a no brainer, keep the mechanical fan, but get a new one every five years or so, and install a new radiator.

YMMV, but if doing serious motoring, a new radiator makes a difference if OEM radiator has not been changed out.

[iHateVolvoPeople]

Originally Posted by 84B23F

If running hilly/mountainous terrain mostly, its a no brainer, keep the mechanical fan, but get a new one every five years or so, and install a new radiator.

YMMV, but if doing serious motoring, a new radiator makes a difference if OEM radiator has not been changed out.

On my 93 245, I'm using a stock clutch and a new autozone aluminum radiator. Upon coldstart the fan clutch stays engaged for minute and then disengages. I've noticed lately that if it gets warm and the clutchs RE engages, it stays engaged for the rest of my trip rather than disengaging when it should. I assume it's just getting worn out? My old fan clutch that was on the +t car is 100% engaged 100% of the time..haha

I want my mechanical fan to free wheel when not need but I also want it to engage HARD when it needs to, as well as disengage HARD when it's not needed. Will a new fan clutch likely give me this? The car has no issues staying cool.

[84B23F]

Originally Posted by 93Volvo240

Upon coldstart the fan clutch stays engaged for minute

Normal for a viscous fan clutch

if it gets warm and the clutchs RE engages, it stays engaged for the rest of my trip

Yes/No...how much engine load, if AC is on, and outdoor air temp determines fan engagement operation.

Viscous Fan Drive

Viscous fan clutches – How do they work and what is the correct way to diagnose them

Viscous Fan Drive Test Procedure

Viscous Fluid Flow - This fluid flow is regulated by a bi-metallic spring that opens and closes a control valve. The fluid flows from a reservoir to the area between the plates at higher engine temperatures and returns to let the fan spin more freely as the engine cools. These fans are more efficient than flex fans that are controlled by engine speed instead of temperature. As the engine speed increases the blades of a flex fan change their angle.

[iHateVolvoPeople]

Originally Posted by 84B23F

Normal for a viscous fan clutch



Yes/No...how much engine load, if AC is on, and outdoor air temp determines fan engagement operation.

Viscous Fan Drive

Viscous fan clutches – How do they work and what is the correct way to diagnose them

Viscous Fan Drive Test Procedure

Viscous Fluid Flow - This fluid flow is regulated by a bi-metallic spring that opens and closes a control valve. The fluid flows from a reservoir to the area between the plates at higher engine temperatures and returns to let the fan spin more freely as the engine cools. These fans are more efficient than flex fans that are controlled by engine speed instead of temperature. As the engine speed increases the blades of a flex fan change their angle.

Thanks for those links. I'm thinking it's just getting old, I'll replace it in the near future. The mechanical fan should definitely disengage once I get on the highway (AC off) but it doesn't. Have you ever had a tropical fan clutch?

[84B23F]

Originally Posted by 93Volvo240

Have you ever had a tropical fan clutch?

1982 Chevolet V8, which was twenty years old at the time; replaced radiator/fan-clutch (heavy duty), and took a 3,200 mile round trip over several mountain passes from North Central Kansas to Salem, Or.

Yes, there was some extra noise, but the fan-clutch was bought for a reason, to keep transmission and engine within their design temperatures.

Otherwise, I'd get a normal fan-clutch, unless I drove in a city all the time.

[photoman327]

Originally Posted by 84B23F

1982 Chevolet V8, which was twenty years old at the time; replaced radiator/fan-clutch (heavy duty), and took a 3,200 mile round trip over several mountain passes from North Central Kansas to Salem, Or.

Yes, there was some extra noise, but the fan-clutch was bought for a reason, to keep transmission and engine within their design temperatures.

Otherwise, I'd get a normal fan-clutch, unless I drove in a city all the time.

My 87 came factory with a tropical.

[84B23F]

Originally Posted by photoman327

My 87 came factory with a tropical.

GM has used the expression "Heavy Duty" (HD Cooling System), which would have been available on 427-450 HP engines, but not all vehicles came stock with HD Cooling System.

YMMV, depending upon intended usage/location(s)...

[photoman327]

Originally Posted by 84B23F

GM has used the expression "Heavy Duty" (HD Cooling System), which would have been available on 427-450 HP engines, but not all vehicles came stock with HD Cooling System.

YMMV, depending upon intended usage/location(s)...

The GM HD clutch is a big and expensive. I put one on my mothers cube truck one time

[1choice]

Curious if anyone's found the perfect electric fan for just the front.

so it's pretty much plug n play without removing the condenser?
i have an 85 244GL retrofitted to 134a, with a few salvage yards nearby.

[1choice]

I cant really find anything about the fans at all in ALLDATA

but I have access to:

'95 940
'91 940
'89 740gl
and many different mid '90s 850's

edit:
okay so i used ebays parts compatibility chart to see what kind of condenser fans are on the 940s. they don't look like they would fit without a bunch of modification or a bunch of brackets.

Okay so this condenser fan with these bolt holes:

fits: 940, 740, 760, 780

This makes me think none of those models condenser fans will fit my 85 244GL's condensor. I guess i need to find the post a dozen pages back about whiich make and model condensor fan fits

[tryingbe]

Originally Posted by 1choice

Okay so this condenser fan with these bolt holes:

fits: 940, 740, 760, 780

That's the radiator fan, though in many cars, it was also used as a condenser fan.

[DMFWallace]

So here's a couple pictures of my half-ass electric fan shroud. The shroud is from a late 80s 740TIC (bought from philski I believe?) and the fan is from any 940/850/SVC70. Tabs were cut from spare sheetmetal and machine screwed through the shroud and I used short bolts with lock washers to mount the fan in such a fashion it won't be hard to take apart if need be. I'm planning to fill the gap between the fan body and shroud with strips of adhesive backed foam or just friction-fitting some meaty strips in the gap.

So tell me how long it'll be before this thing breaks from vibration:

[tryingbe]

Take the bolts/nuts off and use red loctite.

[DMFWallace]

Originally Posted by tryingbe

Take the bolts/nuts off and use red loctite.

I usually try to avoid loctite, especially in places where I can't apply heat. I wanted to make it easy to take apart. Do you think I'd be safer with Nylock nuts than lock washers? Or should I really use loctite and avoid locking washer/nylock setups?

ALSO! I cannot decide on how I want to actuate this fan.. What I really would like to do is use an inline tee in the lower radiator hose with, say, a 185* switch. I don't like the idea of radiator probes albeit people have used them successfully, and if I could go with a tee instead I'd love to do that. Any input is appreciated!

[volvator245]

Used the setup with the BMW double temp switch in the upper rad hose & very happy with that. Occasionally starts on low speed in traffic jams, never heard the high speed (but it works ).

[tomasss]

Same here on my '88 760 w.B280F, BMW double switch in the upper hose, dual speed efan from 960, relay module from 960, works like a charm.
By the way the viscous clutch was partially stuck and over-cooling the engine, with the efan it is able to fully warm now

[84B23F]

Originally Posted by tomasss

BMW double switch in the upper hose, dual speed efan from 960, relay module from 960, works like a charm.

Is there a FREE WHEELING DIODE is that setup?

FREE WHEELING DIODE -Since the motor is an inductive load and an inductor is an energy storage device, when the contacts of the relay open, the energy that is stored in the motor has no place to go. The voltage increases (negatively) and a spark is created across the relay contacts, greatly reducing the contact service life. If a diode is placed (reverse biased) across the motor, it will not conduct in normal operation but will conduct when the relay contacts are opened, thereby suppressing the spark. The current is said to freewheel through the diode and the motor after the supply current from the battery is interrupted. This voltage spike can get unbelievably high, hundreds of volts for a 12V system. Use a 1N5404 which is rated at 3A, 400PIV.

[tomasss]

Originally Posted by 84B23F

Is there a FREE WHEELING DIODE is that setup?

No idea...the fan and the relay is the OEM configuration as used in all stock 960's, so I guess this potential issue has been taken into account from the factory...

[84B23F]

Originally Posted by tomasss

No idea.....

Well, you got a cathode-ray oscilloscope, or maybe a digital storage oscilloscope? Check it out

[Graveyard]

Originally Posted by tomasss

No idea...the fan and the relay is the OEM configuration as used in all stock 960's, so I guess this potential issue has been taken into account from the factory...

..........Which doesn't happen as often as we'd like. That much I got. This thread has been a tutorial of sorts for me. Thanks for all the contributions here.

[Wilford Brimley]

I'm doing this right now.....just not sure what relay to get

[DMFWallace]

So I want to put in a switch in the dash for high speed fan to cool it off before I park or whenever.. but I don't really understand much about circuits and I'm wondering if by chance the thermal switch in the lower hose engaged the low speed circuit while I had the high speed switch on if it would create any issues. Anyone have some insight on how to do this?