Electric Cooling Fans?
Electric Cooling Fans?
Any advice on how to trigger the fan...and what temp range?
I usually, in my Volvos, use a SAAB fan switch...it splices into the lower radiator hose. Temp ranges are just higher than the t-stat...
I'm new to Diesels so I don't know if there is anything majorly different about the cooling system...it's temp ranges or where to get my temp reading from, to trigger fan.
In case you're wondering, the plan is to ditch the fan behind the radiator, to make room for a heat exchanger, so I can use a air/water intercooler.
Mylesofsmyles
02-16-2015, 01:59 PM #1I'd like to fit an electric cooling fan to my '82 300D Turbo. Goal is to remove the AC fan, behind the radiator, and use a 2-speed e-fan, in place of the mechanical unit. I have all the pieces, from a Volvo V70...it should work nicely.
Any advice on how to trigger the fan...and what temp range?
I usually, in my Volvos, use a SAAB fan switch...it splices into the lower radiator hose. Temp ranges are just higher than the t-stat...
I'm new to Diesels so I don't know if there is anything majorly different about the cooling system...it's temp ranges or where to get my temp reading from, to trigger fan.
In case you're wondering, the plan is to ditch the fan behind the radiator, to make room for a heat exchanger, so I can use a air/water intercooler.
The BMW switches are on the passenger side of the radiator near the top. Here are specs
BMW Temp Switches part #’s
BMW 61311378078 190o/210o
BMW 61318361787 176o/190o
Let me know if you need a wiring diagram.
Bob
charliebob
02-16-2015, 06:01 PM #2I use a BMW two-speed temp switch in the OM617 T-stat housing, with a volvo two-speed relay and a t'bird two speed fan. This is a fairly common combination with hot rodders.
The BMW switches are on the passenger side of the radiator near the top. Here are specs
BMW Temp Switches part #’s
BMW 61311378078 190o/210o
BMW 61318361787 176o/190o
Let me know if you need a wiring diagram.
Bob
I could use a wiring diagram for the A/C circuitry
Mylesofsmyles
02-16-2015, 06:47 PM #3Where in the Tstat housing did you put it? I'm new to these cars...is there a threaded bung there already, or did you get creative?
I could use a wiring diagram for the A/C circuitry
Let me know if the pic does not show (I am having trouble with this site in both Safari and Firefox)
Note that the relay is continuous duty, which is different from the typical relay.
There are 2 temp sensors in the t-stat housing. If you delete EGR, one is not needed. The BMW temp switch will screw right in. 14mm I think. There is also a spot (dimple) on the housing (the outer part you remove to replace the thermostat) where you can drill and tap for the BMW switch as well.
The Taurus/T'Bird fan shroud is almost exactly the same size as the W126 radiator, and that fan flows much more than most aftermarket electric fans.
I'll get pics of the t-stat housing tomorrow.
Bob
![[Image: Fanwiring.jpg]](http://i832.photobucket.com/albums/zz249/charliebob13/Fanwiring.jpg)
charliebob
02-16-2015, 07:14 PM #4Here is a wiring diagram I patched together. The blue rectangle, "cooling fan" is just a 40 amp fuse.
Let me know if the pic does not show (I am having trouble with this site in both Safari and Firefox)
Note that the relay is continuous duty, which is different from the typical relay.
There are 2 temp sensors in the t-stat housing. If you delete EGR, one is not needed. The BMW temp switch will screw right in. 14mm I think. There is also a spot (dimple) on the housing (the outer part you remove to replace the thermostat) where you can drill and tap for the BMW switch as well.
The Taurus/T'Bird fan shroud is almost exactly the same size as the W126 radiator, and that fan flows much more than most aftermarket electric fans.
I'll get pics of the t-stat housing tomorrow.
Bob
I am in the process of deleting EGR, in the midst of my project, so if I identify which temp switch is used for that, I can use this BMW switch...or something similar...
Why not run the wiring like Volvo did...with the constant 12v to relay, with fusible link, right to batt? Yes the fan will run after key-off, but only for a few seconds, as it lowers temps to satisfactory.
I'm going to wire it as I've done on my other cars....just as Volvo did....I see though, that you're using the BMW switch to trigger both the low and hi settings on the fan....
My plan, again, as Volvo did it....use a coolant temp switch for the low setting...most used function. High speed setting is triggered by AC system, to supplement the fan that was behind grill. That's really what I need a wiring diagram for....to figure out where to get my signal for AC system
Mylesofsmyles
02-16-2015, 08:52 PM #5Bob thanks!
I am in the process of deleting EGR, in the midst of my project, so if I identify which temp switch is used for that, I can use this BMW switch...or something similar...
Why not run the wiring like Volvo did...with the constant 12v to relay, with fusible link, right to batt? Yes the fan will run after key-off, but only for a few seconds, as it lowers temps to satisfactory.
I'm going to wire it as I've done on my other cars....just as Volvo did....I see though, that you're using the BMW switch to trigger both the low and hi settings on the fan....
My plan, again, as Volvo did it....use a coolant temp switch for the low setting...most used function. High speed setting is triggered by AC system, to supplement the fan that was behind grill. That's really what I need a wiring diagram for....to figure out where to get my signal for AC system
![[Image: IMG_1316.jpg]](http://i832.photobucket.com/albums/zz249/charliebob13/IMG_1316.jpg)
charliebob
02-17-2015, 01:57 PM #6Here is a pic of the t'stat with the BMW temp switch replacing the EGR sensor. Out near the neck of the outlet you can see a dimple cast into the housing. It can be bored out and threaded for another thermo sensor/switch.
Now, I've got to figure out the AC trigger
Mylesofsmyles
02-17-2015, 02:11 PM #7Cool...I've got it from here then, for the low-speed, coolant temp trigger...
Now, I've got to figure out the AC trigger
Have you checked air flow of the volvo fans compared to the taurus/t'bird/lincoln fan? The volvo fans may be enough, but I suspect that they flow considerably less that the ford fans. Nevertheless the volvo fans may be sufficient.
charliebob
02-17-2015, 02:22 PM #8I have yet to install AC, but my plan is to simply let the two-speed fan be triggered by temp, and not wire the AC into the fan circuit.
Have you checked air flow of the volvo fans compared to the taurus/t'bird/lincoln fan? The volvo fans may be enough, but I suspect that they flow considerably less that the ford fans. Nevertheless the volvo fans may be sufficient.
When I was learning how to wire them in my Volvos, I learned that there were switches in the AC system...one of which is used to trigger the high-speed setting. Could one use a temp sensor, certainly. That said, the A/C system is designed with a pressure switch, to trigger the A/C fan. I'd like to minimize modifications, and keep that working as it was designed....just change which fan it triggers.
Mylesofsmyles
02-17-2015, 02:48 PM #9I have not...however, they've stood up to the abuse to all my Volvo 240 projects, ranging from a mildly pepped up 2.1L NA motor...and two twin cam, turbo motors between 330-400hp. I'm pretty darn confident the Volvo fan is plenty heavy duty.
When I was learning how to wire them in my Volvos, I learned that there were switches in the AC system...one of which is used to trigger the high-speed setting. Could one use a temp sensor, certainly. That said, the A/C system is designed with a pressure switch, to trigger the A/C fan. I'd like to minimize modifications, and keep that working as it was designed....just change which fan it triggers.
Mylesofsmyles
02-17-2015, 02:54 PM #10I will need to find another shroud however....I don't like the V70 shroud....the 960 shroud is a lot easier to work with. When I trim it down, it should fit over the Benz radiator perfectly. Lol, famous last words.
![[Image: 208104.png]](http://badges.fuelly.com/images/sig-us/208104.png)
Clearance looks to be no issue
Mylesofsmyles
02-17-2015, 04:43 PM #12It's a lot better fit with a 960 shroud...
Clearance looks to be no issue
![[Image: fan%20schematic.jpg]](http://s1250.photobucket.com/user/Mercedes_Power/media/fan%20schematic.jpg.html)
Granted, I also ripped the A/C condenser out so no added heat from A/C and better flow through radiator because the condenser is gone. If she starts to get warm in traffic, then I just switch on the condenser fan in front of the radiator to blow through it, and or hit the heater.
1982 300D Turbo ... 3,6xxlbs, No fan, No AC, Hood Stack, No ALDA, No rear bumper and stuffed front, A/W Intercooled, Injectors by Greezer and HUGE Pre-Chambers with help from OM616 & Simpler=Better, Fuel Cranked up, 60 Trim Compressor wheel, EGT, EMP, Boost 50" Rigid Radius bar on roof Aux tank for a total of 48 Gal Of Diesel! Odyssey PC-1750 Battery in trunk, 27"x8.5"/R14 Maxxis BigHorn Mud Terrains, In June '14 issue of Off Road Mag
AX15 Jeep Trans swap in progress....
Captain America
03-05-2015, 01:07 AM #14I don't have a fan of any type on engine side of radiator. The 617 Simply doesn't need one in California. My temps run just a tick above 80 all day everyday.
Granted, I also ripped the A/C condenser out so no added heat from A/C and better flow through radiator because the condenser is gone. If she starts to get warm in traffic, then I just switch on the condenser fan in front of the radiator to blow through it, and or hit the heater.
1982 300D Turbo ... 3,6xxlbs, No fan, No AC, Hood Stack, No ALDA, No rear bumper and stuffed front, A/W Intercooled, Injectors by Greezer and HUGE Pre-Chambers with help from OM616 & Simpler=Better, Fuel Cranked up, 60 Trim Compressor wheel, EGT, EMP, Boost 50" Rigid Radius bar on roof Aux tank for a total of 48 Gal Of Diesel! Odyssey PC-1750 Battery in trunk, 27"x8.5"/R14 Maxxis BigHorn Mud Terrains, In June '14 issue of Off Road Mag
AX15 Jeep Trans swap in progress....
Mylesofsmyles
03-05-2015, 01:09 AM #15I'm just going to stick with the clutch fan, on this car after all
W124 om606 HX40 finished and it's a beauty 450bhp/456ft-lbs
maxypriest
03-05-2015, 05:19 AM #16i'm planning to fit some slim line electric units behind my rad, i have axed the old mech one.
W124 om606 HX40 finished and it's a beauty 450bhp/456ft-lbs
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