4.5 electric fan conversion

[berfinroy]

I can now report favorably on the electric fan conversion on my 73 109 4.5. Although the temperature will rise higher in traffic than with the huge stock viscous fan, it does not get anywhere near the red danger zone even with the air on in traffic. And it returns to around 180 degrees on the highway (Note: tested in CT at around 90+ degrees; can't say about AZ @100 or so).

Parts are about $220 incl. shipping as follows:

1) From A1 Electric:
i) Spal 16" medium profile pull style fan, #3010516.
ii) Fan relay and wiring harness, #FRH.
iii) 4 .75" mounting brackets #30130011.

2) From Stieger Performance:
i) 3/8" threaded temperature sensor adaptor for 1 1/2" ID hose-in natural aluminum (cheapest).

3) From Rodney Dickman (Fiero parts!):
i) 210 on 200 off high temperature thermo switch.

I tried a variety of lower temperature on/off switches, and they are just not suitable. The 210/200 works best primarily because it goes off when you get out off traffic like it should while the shut-off temperature of the others is just too low--the fan unnecessarily stays on much of the time.

Don't buy the rubber fan gasket from A1; the fan will not clear the water pump pulley. To snug the fan up to the radiator after installation with the A1 mounting brackets, use a couple of generic plastic pin mounts from NAPA that can be threaded through the radiator and condenser cores. Discard the stock fan shroud and attach the Spal fan brackets to the 4 points that held it on.

Of course the temperature sensor body has to be grounded with a seperate wire since the Stieger adaptor is placed midway in the upper radiator hose. Locate the adaptor so that the temperature sensor is underneath.

Being a bit obsessive as I am, I included a manual under dash turn on switch, but it really isn't necessary--the correct temperature switch does its job well.

I have observed a material improvement in performance--and presumably economy as well, although I haven't measured that.

[Mike D]

And another option is covered here:
Fan Clutch question

I run my three W114's using the electric fan only and that's here in Tucson. I haven't converted my W126 (mainly 'cause it isn't running at the moment).

I prefer the adjustable thermostat but our man from the Phillipines found a sensor from a Japanese import which activates at 50C or so. I think 50C is a bit cool but there's probably a 70C one out there.

[GaryF]

Just curious, did either of you upgrade your battery or alternator as well?

[Mike D]

Nope but I always use the heavy duty batteries in all my cars. Its almost a requirement out here in the desert.

My wife's 250C is Megasquirted as well and even with the extra draw for the electric pump, ECM and injectors' relays there never has been a problem. If you can believe the Megatune's gauge then it runs at 13.9V daytime when the fan kicks on and 13.1V at night with the lights on.

[berfinroy]

I have not found it necessary to upgrade the alternator or battery. With the setup I described, it really is an intermittent "traffic" fan, and I don't use it as a commuter vehicle.

[Takernz_30]

Originally Posted by Mike D

And another option is covered here:
Fan Clutch question

I run my three W114's using the electric fan only and that's here in Tucson. I haven't converted my W126 (mainly 'cause it isn't running at the moment).

I prefer the adjustable thermostat but our man from the Phillipines found a sensor from a Japanese import which activates at 50C or so. I think 50C is a bit cool but there's probably a 70C one out there.

I used a temperature switch from Suzuki MiniVan, I placed it at the cylinder head where the heater connection used to be, the switch triggers at 60C off at 50C too low and used that in low fan speed, If I turn AC on or coolant temp. at 85C, the fan will spin faster, pretty much similar set-up for 260E,300E W124.