a couple questions on auxiliary fan wiring and sensor

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mark99

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a couple questions on auxiliary fan wiring and sensor

Don L told me later cars had a temperature sensor in the radio
I will have the shop that is rebuilding mine add a fitting, he said it is no problem
Could someone explain where that fitting should be located? a couple photos and dimensions?

Second, how do I wire it in so that the aux fan comes on with the AC and with a temperature input?
I assume there is an electrical component I need to source
(and that keeps the fan from inoculating on and off?)

Thanks
 
Don probably said in the radiator not the radio.
There is the aluminum radiator that Don created for the E9 and includes the temp sensor setup.
With the original radiator I think it would be triggered by dual temp sensors on the engine side of the cooling system.

mark99 said:
a couple questions on auxiliary fan wiring and sensor

Don L told me later cars had a temperature sensor in the radio
I will have the shop that is rebuilding mine add a fitting, he said it is no problem
Could someone explain where that fitting should be located? a couple photos and dimensions?

Second, how do I wire it in so that the aux fan comes on with the AC and with a temperature input?
I assume there is an electrical component I need to source
(and that keeps the fan from inoculating on and off?)

Thanks
Click to expand...
 
radio, that's funny
I talked to Don about the alum radiators but none ready at this time or I would have gotten one
He said, hope I don't misquote too badly, early cars, switched on by AC only, later sensor in radiator

so still looking for location and wiring / components

Thanks
 
I posted the diagram recently with the diode

radiator: recore or new aluminum

Before you sell your Walloth rad better check to see what it costs to recore these radiators! In WI I don’t think the extra sensor to trigger the electric fan is needed and I don’t have that here in CA.
e9coupe.com e9coupe.com
 
Here is the wiring diagram for initiating the aux fan (3) with the a/c temp switch (5). If you car came with a/c, this should be how your car is wired.

The diagram Chris posted is an add on to this circuitry that uses the temp sensor as an alternative method of initiating the aux fan when the a/c is not operating.

9D81D5A2-B2D0-436F-902C-3BC8CEC215C4.jpeg
 
Using a Spal fan and was strongly considering wiring it so it would also come on with H2O temp
 
Chris, Where did your diagram come from? It appears to be 74 and later without the bypass relay in the 73 and earlier coupes with the four pin fan switch.
 
Chris - I actually grabbed this off the forum a while back; not sure of the source. (You perhaps?)

I posted that because of Mark's reference to "later cars" at the beginning of this thread. Here is the material I have for a 72:

Wiring 1.jpg
Wiring 2.jpg
 
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