Help with fan issue (1 Viewer)

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Guys,

Having some issues with my fan.

74 w 350 is the vehicle. I haven't owned it long so I am still learning about it as I go.

It has an aftermarket fan (not sure what it came off)



that has an on/off toggle switch on the dash. Not exactly sure why it wasn't wired to ignition, but anyway.

Noticed tonight that I couldn't hear the fan running . Thankfully I was only driving 5 minutes away so no big deal. Got home to take a look.

Please excuse my lack of knowlege here.

I am getting power to the on/off switch so know it is working.
I am getting power to the hot wire running to fan (12v)
I have a good ground.

There are 4 prongs on fan, not sure what all 4 are for.



From what I can see, only 2 wires were running to the fan - power and ground. For all I know there was another that came loose, although I couldn't see any.

I systematically tried the hot on each of the 4 prongs while grounding the other wire. The fan did not start on any prong.

My questions:

Does this mean the fan is bad?
Are there any other tests I can run before replacing fan?
Should there be more than a power and a ground running to fan?
Do these vehicles have any type of fan relay?

Thanks for any advice you can offer. Regards,

Jonny
 
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if you bypass the relay there should be only two wires going to the fan one hot one groung thats all you need to test it . i can see the wires on the bottom of the shroud. there should be 2 powers going to the relay when its on. maybe the relay is bad check with the 2 wires first
 
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if you bypass the relay there should be only two wires going to the fan one hot one groung thats all you need to test it . i can see the wires on the bottom of the shroud. there should be 2 powers going to the relay when its on. maybe the relay is bad check with the 2 wires first
Excuse my ignorance, but where is the fan relay? I am used to modern cars...

So by putting the 2 wires directly on the fan as I did earlier, than in essence would bypass the relay? Being that didn't help, then it would indicate the fan is bad?

Thanks,
Jonny
 
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if you hooked them up to the thing on the side i would bypass that and find the wires that come off the fan motor itself and check that way. if thats what you did then i would think its safe to say the fan is no good
 
Joined
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Enola, PA.
 
 
A typical wiring diagram is here http://www.rondavisradiators.com/Spal fan wiring instructions.pdf

Your fan "should" be running off a thermostatically controlled relay....if your radiator isn't up to temp the fan will not come on. The switch on the dash "should" be a kill switch for water crossings, etc. Like Ken suggested, jump straight from the battery to the hot lead on the fan itself to test it.
I run a SPAL wired as above with a 195 sensor. On cold days (like today) it may not come on at all.
Your fan may be functioning correctly....you just didn't get hot enough for it to kick in.
 
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if you hooked them up to the thing on the side i would bypass that and find the wires that come off the fan motor itself and check that way. if thats what you did then i would think its safe to say the fan is no good
Thank you. I didn't bypass the thing on the side, but will try that this evening.

A typical wiring diagram is here http://www.rondavisradiators.com/Spal fan wiring instructions.pdf

Your fan "should" be running off a thermostatically controlled relay....if your radiator isn't up to temp the fan will not come on. The switch on the dash "should" be a kill switch for water crossings, etc. Like Ken suggested, jump straight from the battery to the hot lead on the fan itself to test it.
I run a SPAL wired as above with a 195 sensor. On cold days (like today) it may not come on at all.
Your fan may be functioning correctly....you just didn't get hot enough for it to kick in.
Unfortunately, the fan is directly wired in, and not wired to a thermostatically controlled relay. When I hit the on/off toggle, it turns on, regardless of the engine temps.

I guess I need to find the wires running off the fan itself and do as you suggested. Thanks again guys,
Jonny
 
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Joined
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well maybe the thing on the side of the shroud is the relay. the relay can be anywhere. i see on the top picture there wires lying in the bottom of the shroud are those wires going to the fan motor. if so then jump those to see if the motor works at all. there should be 2 wires one ground one hot just jump from battery. i bet the relay is the thing on the side.
655bf6b9.jpg
 

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