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Old 05-30-2007, 10:08 PM
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Electric fans not fanning when switched on

I'm in process of a V8 s10 swap, and installed two electric radiator fans from a '97 (or close) Caddy Seville. I tested the fans to make sure they worked before I put em in- but after finishing all my wiring/grounding, I can't get em to run.

I used relays from a Crown vic- One relay per fan. I have the relay coil + ran to a fuse box "ign" socket (16 ga, each relay separately w/ inline fuse), 12v power to relay from the terminal block (10ga and fuse linked), relay coil ground to a switch in the cab, and power from relay(10 ga) ran to fans (which are grounded).

Both coil ground wires are ran through a sorta small switch- Could I not be getting enough ground to complete the circuit to close in the relay? Is the single spade terminal (per relay) stuck in the "ign" socket good for my 12v switched source? My relays came from the Crown Vic's fuel pump and something else- if they're too small would that prevent the fans from running?
I have the original relays from the Caddy (didn't use em b/c of special dang terminal ends that I couldn't get b/c nobody seems to stock em)

Sorry for the long post- I'd appreciate any advice

Nooj

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Old 05-31-2007, 06:16 AM
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The switches should be providing a good referance to ground. Do you have a digital volt ohm meter to check the circuit with? Since you are using used components (relays) I would suspect these first. You have confirmed the fans are working, so look at the relays. Make sure you have voltage, confirm it's there.

Vince
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Old 05-31-2007, 07:43 AM
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fans not running

sorry,iposted my original reply to the wrong thread"ignition help"Confirm power from your ign term.Confirm power from your power block to your relay. Check resistance across your relay coil.Check continuity across your relay contacts. It is doubtful that your switch is to small to run your relay at least for a short time.However the switch could be bad. Check it.Run jumpers to a known GOOD ground , atleast until you get it working properly.Electrical gremlins are usually ground related.
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Old 05-31-2007, 11:32 AM
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look at these PAGE & be sure you have them wired correctly...joe
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Old 05-31-2007, 11:57 AM
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Doc here,

Are you using a thermo switch for automatic switching predicated on engine temps? Or are you using manual switching?

You relays , IF you are using Bosch type (industry standards) should be wired as follows:
  • Terminal #85 = 12 volts , switched , fused, Power.

  • Terminal #86 = switched ground or thermo switch.

  • Terminal #87 = 10 gauge wire to fuse link or maxi fuse , to battery power.

  • Terminal #30 = 10 gauge wire to the fan motor (S).

  • Terminal 87a = is not used in this application.

If your relays are other than Bosch type, I suggest going to the auto parts store and picking up a couple..the pin-out will be on the bottom.

The #85 and 86 terminals are coil power & Ground.

The #30 Terminal is the center wiper or movable contact.

The 87 terminal is normally open terminal.

the 87a =Terminal is normally closed terminal.

Doc :pimp
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Old 05-31-2007, 09:42 PM
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Hey guys- thanks for all the input!! I finally got it working

Apparently my "quick splice" on the switch wasn't grounding well (had to burnish some paint off my ground connection as well)- so I used a crimp splice on it. That was problem #1.

And I figured out that I had the power and ground wires reversed on one of the fans (blowin the wrong way, lol). One was white, and one was black- I figured the black was the ground... but I guess I had it backwards.
But both fans come on with the flip of a switch now And they blow hard enough to knock the hat off your head! These fans are great- enough air flow that you can feel the air being pulled through the radiator from a couple of feet in front of the truck- and that's without a shroud.

Thanks for all your help, fellas! I appreciate the info on wiring the relays, Doc. I may end up going to two relays per fan in the near future- just for good measure

Nooj
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Old 06-01-2007, 02:13 AM
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Doc here,

KEWL!

good to hear it is working..

keep us updated.

Doc
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