Engine Effective duel E-fan sequence

[BeaverMeat]

Going with a Contour V6 fan assembly on the Volstang (‘81 Volvo 244 with a 5.0L/T-5)... fits the Volvo diesel rad perfectly-ish.

I’m going with two temp ranges for the fan kick-in. 97-92*c (207-197*f) and 102-97*c (215-207*f)

That should be about right for a 5.0L with a 195*f t-stat to stay with-in the 200-210*f operating range.

What is the most effective fan sequence?

Run the driver side fan at 207* at low speed only with the pass side fan at 215* at high speed only?

Or

Run both driver and pass side fans at low speed at 207* then kick-in high speed at 215*?

OR

Run the driver side fan in a duel speed sequence of 207 low and 215 high. The pass side fan will be a high speed only kick in at 215?

Thanks in advance.

 

[7991LXnSHO]

Following for dual temp ideas. I like your brainstorming.

First, I’d stop the duel. If they shoot or cut each other with rapiers, it will not end well.
(Isn’t auto-correct fun? )

 

[KRUISR]

I run the Contour fans just like they do in the Contours. Both fans on for low and both on for high. I have a fan control switch basically the same as you are listing. Here is how I did it (and done on Contours - except the relays are trigger by ECU with Contour).

I detailed my install here...

Electrical - Contour Fan Install with OEM controller

So first off, this may have been done before but my install is a bit different than all I have read in the past. If nothing else it is a different way to hook up the system. I used as much of the Contour electrical system as I could and then simply connected my controller. Oh ya, this is a...

www.stangnet.com

I have been running this way for over 4 years now with no issues.

 

[KRUISR]

This is how the factory wiring harness is connected to fans and what feeds are...

 

[BeaverMeat]

Awesome! Thanks!

I hope my fans come with some sort of wires. There isn’t too many of these around anymore (In Canada) and took what I coildMight have to ad hoc it.

I’m hoping to use a Volvo 7/9 series fan relay if I can find one. What else would work? I know I’ll have to use two sets of switches.

 

[KRUISR]

I used a sensor/switch from a 99-01 Audi/VW 1.8L Turbo. Can find them in Beetles, Golf, Jetta, A4 and others.

Some have used a sensor from a BMW (not sure of year).



I pulled the sensor and pigtail from the wreckers and have used that. It is a large thread though. Off the top of my head it is M22x1.5 i believe. I used an Axle nut from a Contour and welded it to a 4" piece of 1-1/2 pipe and installed in lower rad hose.

 

[BeaverMeat]

I’m going to use two different sensors. A 97-92* from a Toyota in the t-stat housing for the low speed and a 102-97* in the radiator for the high wired into a Volvo relay.

I’m hoping there won’t be any gap in the sequence. Starting to second guess my set-up. I guess I’ll have to try it out and see what happens.

 

[KRUISR]

Two sensors is not a problem, just trying to locate both in the system. I would actually recommend installing them in reverse. Put the low speed sensor (Toyota one you mentioned) in the rad and the higher one in the T-stat housing (assuming these are the only locations you have).

Here's why... putting low speed in discharge side of rad will only turn them on when coolant temp gets up to the set point. If installed in the t-stat housing you could be turning on the fans just because the t-stat opened (as you temp range is close to OEM t-stat temp - actually the temp you should have the engine at for best efficiency). The fan will then run unnecessarily, just because engine is up to temp - not the coolant.

Higher range sensor in t-stat makes for some insurance, because engine will need to be at 102*C is 215*F to kick on high which is a good thing.

If looking for a way to install low temp sensor in lower rad hose, try one of these off eBay...



If you were planning on installing in t-stat due to size, the hole provided here may be the correct size already. Get the 40mm version. Then simply cut the lower rad hose and install with the clamps. In my opinion this is the absolute best location for a temp sensor to control e-fans.

I have taken one of these and modified it to fit my larger diameter sensor above. Mine uses a M22x1.5 thread and with some mods will just fit. If the Toyota sensor fits, that's even better.

If you get one of these, you can still put the high speed in the rad (another good choice).

 

[BeaverMeat]

Two sensors is not a problem, just trying to locate both in the system. I would actually recommend installing them in reverse. Put the low speed sensor (Toyota one you mentioned) in the rad and the higher one in the T-stat housing (assuming these are the only locations you have).

Here's why... putting low speed in discharge side of rad will only turn them on when coolant temp gets up to the set point. If installed in the t-stat housing you could be turning on the fans just because the t-stat opened (as you temp range is close to OEM t-stat temp - actually the temp you should have the engine at for best efficiency). The fan will then run unnecessarily, just because engine is up to temp - not the coolant.

Higher range sensor in t-stat makes for some insurance, because engine will need to be at 102*C is 215*F to kick on high which is a good thing.

If looking for a way to install low temp sensor in lower rad hose, try one of these off eBay...



If you were planning on installing in t-stat due to size, the hole provided here may be the correct size already. Get the 40mm version. Then simply cut the lower rad hose and install with the clamps. In my opinion this is the absolute best location for a temp sensor to control e-fans.

I have taken one of these and modified it to fit my larger diameter sensor above. Mine uses a M22x1.5 thread and with some mods will just fit. If the Toyota sensor fits, that's even better.

If you get one of these, you can still put the high speed in the rad (another good choice).

yup... you were correct. The sensor picks up the heat from the block and the fans stay on for a long time because of heat soak, etc.

I guess I have two options. Set it up in reverse (finding a plug style sensor in the 207-197 range is difficult) or increase the temp range on the t-stat housing sensor.

 

[KRUISR]

Can you post a pic of where in rad your sensor goes? Also any part numbers or descriptions of the sensors you are thinking (or did use)? Thread sizes for the sensors?

 

[KRUISR]

finding a plug style sensor in the 207-197 range is difficult

Depends on what one you had in mind already. The Audi one I used is dual range, low speed kicks on at 95 C, off at 82C (approx. 195/183). High speed comes on at 102C, off at 92C (approx 212/190). But to be honest, high has NEVER come on.

If you can mount the Toyota low speed sensor in the rad (or near it - lower rad hose), I would just put high speed on a toggle for back up (not worry about an automatic triggering).

 

[BeaverMeat]

This is the rad switch (can’t figure out how to post pics yet)

Thermostatic Fan Switch 740 940 1992-1994 REGINA

>Volvo 3547932 9135545 dr 4dr 5dr 700 740 900 940 fan rwd 1992 1993 1994 aw70 aw71 door b230f sedan volvo wagon 113172 regina switch 9135545 genuine nonturbo thermostatic

www.ipdusa.com

T-stat switch (M12x1.25 on an 3/8 adaptor in the housing):

DRiV | Quality Auto Parts

Count on DRiV for auto parts that deliver the quality, safety and performance you demand.

drivcat.com

 

[JD1964]

Here's and alternative fan control idea. I've got this on my Contour fans on my 92 LX. Love it and would do it again, no complaints whatsoever, (except maybe a tad pricey, and takes a while to acquire since the dude makes to order)

s50 s70

 

[BeaverMeat]

Yeah... too much for my blood. Wanting to go analog with off-the-shelf parts. May have to get a heat laser to find the the exact temperature of the t-stat housing Vs the rad.

or order up some new sensors. I have to get the plug style from Europe.