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Make electric fan an on/off switch?

seanile

Member
Joined
Feb 20, 2019
Location
Boston
Give electric fan a manual on/off switch? (no a/c)

soooo i'm going to be doing the a/c delete on my '92 240 (see sig for specs), while i also have in my possession a new electric cooling fan that will obviously be rendered useless following the delete.

my [dumb] question is if it would be viable to finagle a manual power switch, perhaps via the a/c button, to turn on the electric cooling fan at will on the stupid hot days. would this overwhelm the alternator? i am not super knowledgeable with circuitry but have some friends who are and would help me if i enlisted them, but i wanted to run it by you all as a feasibility study first.

or should i just sell the fan and move on with life.

thoughts? questions? eye rolls?
 
Those fans are not really meant to be run all the time. Kind of like an E-Fan setup. I wouldn't bother. The question that remains... isn't it wicked hawt in Boston in the summer? AC Delete... you sure?
 
totally fair. i wasn't considering it as an all the time thing but just a useful extra tool to keep it cool in stop-and-go on the interstates. could always just pour my iced dunkies over the engine if i'm desperate.
i've never been one to use my a/c anyway, i'm more of a drop the windows and turn up the stereo kinda guy.
 
In that case it's a waste of time as the car has lots of headroom in terms of cooling capacity.
 
If you go to Speedway Motors, or JEGS or ..... you can find electric fan controllers. If your radiator tank does not have a fitting for an RTD some of these controllers come with a little rubber seal that fits in under the top rad hose and allows you to slip an RTD in to measure the coolant entrance temperature to the rad. The controllers have an adjustable temperature setting for turning the fan on.

Generally simple installation even for the electrically challenged.
 
What is wrong with you guys? It can't run all the time? Says who? If you aren't interested in his idea, stay out. One person added anything constructive.
I have done this, as an over-ride for a temp switch. Lots of people have done a manual switch. And if that fan is there, I guarantee it was built to withstand a switch sticking on and it running constantly.

OP, some systems have a switch in the lower hose area to tell a fan when the radiator is not removing enough heat. So there's another way to do it. I have even used a headlight switch (or maybe an old pull-switch for wipers) to turn on low and high, using a resistor for low. You can do anything you want.
 
If you go to Speedway Motors, or JEGS or ..... you can find electric fan controllers. If your radiator tank does not have a fitting for an RTD some of these controllers come with a little rubber seal that fits in under the top rad hose and allows you to slip an RTD in to measure the coolant entrance temperature to the rad. The controllers have an adjustable temperature setting for turning the fan on.

Generally simple installation even for the electrically challenged.
that does sound reasonably doable option to have, thanks. i've got nissens 3 row i'm planning on installing this coming spring. haven't looked closely at it and it's packed away at the moment so i'm not sure what fittings it has available.

I have done this, as an over-ride for a temp switch. Lots of people have done a manual switch. And if that fan is there, I guarantee it was built to withstand a switch sticking on and it running constantly.

OP, some systems have a switch in the lower hose area to tell a fan when the radiator is not removing enough heat. So there's another way to do it. I have even used a headlight switch (or maybe an old pull-switch for wipers) to turn on low and high, using a resistor for low. You can do anything you want.
excellent, that's exactly what i was looking for. i appreciate your input.
 
Ok to be a little more constructive. Here's a way to use an 850 E-Fan relay to turn on a fan. No switch necessary if you just use a relay, turns on and off with the car. Temp switch only turns fan on at whatever temp your switch is rated. Get one of these:

39Lgwwom.jpg


Wire it in like so...

g0BdcWjl.jpg


I don't really know the particulars on the AC fan but here's a thread that addresses it.

Questions? PM me anytime.
 
C'mon, kid, don't waste your Dunks like that. I'll meet you in the pahkin lot at Kelly's Roast Beef over in f*hkin' Saugus there and we'll take care of it.

In all seriousness yeah, you could use that switch. I would wire it to a relay, not so that it carried all the current through the switch. I'm sure it's not rated for that.
 
thanks everyone, very helpful. this gives me a lot to work with.
carver, i'll likely shoot you a note in the spring when i get into installing the new radiator, appreciate the offer.

dammit i haven't been to kelly's in too long, thanks for the reminder to get my ass back over there shoestring
 
C'mon, kid, don't waste your Dunks like that. I'll meet you in the pahkin lot at Kelly's Roast Beef over in f*hkin' Saugus there and we'll take care of it.

In all seriousness yeah, you could use that switch. I would wire it to a relay, not so that it carried all the current through the switch. I'm sure it's not rated for that.
I think he's all set, then. Are we all set? I'm all set.
Watch out for that one guy, though. He's storrowed again.
 
I had it hooked up to switch the ground on position 85 on the above diagram. 86 had power from another relay that turns on with the key. I used an all blue a/c switch and grounded one side of the switch to the steel frame.
 
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