Author Topic: ELECTRIC FAN RELAY WIRING  (Read 7043 times)

Offline okuma

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ELECTRIC FAN RELAY WIRING
« on: September 09, 2007, 11:51:22 am »
I INSTALLED AN ELECTRIC FAN TO MY GMC', MY QUESTION IS DOES ANYONE HAVE A DIAGRAM OR CAN YOU  PLEASE TELL ME HOW TO WIRE UP A RELAY FOR THE ELECTRIC FANS?
THE LOWER I GO,..... THE MORE SHE LIKES IT!

Offline CruzinHigh

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Re: ELECTRIC FAN RELAY WIRING
« Reply #1 on: September 09, 2007, 12:44:17 pm »
Yep, we can help you out.

Do you already have the relay or do you need to go buy one?

Depends on how many wire relay you'll be running, but the basic principle is the same.

You'll have a high current side of the relay that will supply the fan with power.  That side you'll want to take power from a good stable source, preferably as close to the battery as you can get.  I would fuse the lead from the relay with a 20A fuse minimum depending on the size of your fan.

The switched side of relay is low current.  How you choose to wire this up depends.  If you want it to be switched from a toggle, just wire the 12v from the switch to the relay, and then tie a ground feed to the other end of the circuit through the low current side of the relay.   If you use a fan switch then the voltage will go through the relay first (constant 12v) and then the fan switch will ground it when the temp reaches the specified setting.

This is just a start, hopefully it is a bit of help.  It will probably require more feedback when you give some more details of your plan.


Mike Carter
1986 Chevy K-10 4x4

8" lift project on the way soon!

Offline okuma

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Re: ELECTRIC FAN RELAY WIRING
« Reply #2 on: September 09, 2007, 06:55:24 pm »
I USED a single E-FAN from a lincoln town car. This fan fits exactly on the radiator with the lincoln fan shroud in its place.. will cover the whole radiator. the fan only has 2 wires (pos. & negative). when connected directly to the battery it makes a big bright spark from the amp draw from the battery.....I don't know the cfm on it but it sure does blow lots of air onto the engine.... What cfm should this fan be?
THE LOWER I GO,..... THE MORE SHE LIKES IT!

Offline VileZambonie

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Re: ELECTRIC FAN RELAY WIRING
« Reply #3 on: September 09, 2007, 07:38:00 pm »
here's a simple fan ckt I quickly drew with paint...

« Last Edit: September 15, 2007, 03:31:36 pm by VileZambonie »
,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline okuma

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Re: ELECTRIC FAN RELAY WIRING
« Reply #4 on: September 09, 2007, 08:40:13 pm »
THANX VILLE ,  to what does the center connection on a 30A relay connect to? this is my fan set-up from a lincoln town...... does anyone know how much cfms is this fan?   thanx everyone for ur help!
THE LOWER I GO,..... THE MORE SHE LIKES IT!

Offline VileZambonie

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Re: ELECTRIC FAN RELAY WIRING
« Reply #5 on: September 10, 2007, 08:28:26 am »

You only need to use the 4 cavities shown. I labeled them like most bosch relays are layed out. Just run the high current through the heave gauge cabling. You can use regular 18-20 gauge wire on the temp switch side of the circuit. What year did you pull the fan off of?
,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline okuma

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Re: ELECTRIC FAN RELAY WIRING
« Reply #6 on: September 15, 2007, 02:16:52 pm »
sorry ville my computer shotdownfor a while >:(.... anyways the fan is from a 92-93-94-95-96-97 styled lincoln towns car.... crown victoria and grand marquis are the exact same e-fans....
THE LOWER I GO,..... THE MORE SHE LIKES IT!