Wiring problem

phat46 · May 28, 2007, 02:54:23 PM

Today I was adding a relay to my electric fan, but I can't get it to work properly. Once i start the fan with the switch it won't shut off using the switch, I have to turn the key off and let the fan stop before it will stay off. Sounds like it's back feeding, but how and where? I got frustrated and left it alone. I hate wiring...while i was installing the relay I managed to unwire all the lights.... :evil:

enjenjo · May 28, 2007, 03:08:46 PM

It sounds like the fan is backfeeding the control circuit. you can isolate the power to the fan from the control circuit to fix it.

phat46 · May 28, 2007, 05:41:32 PM

Quote from: "enjenjo"It sounds like the fan is backfeeding the control circuit. you can isolate the power to the fan from the control circuit to fix it.

That's what I was thinking too Frank. The power to the fan is from a different cicuit than the power to the switch, is that what you mean by isolating the power to the fan?

enjenjo · May 28, 2007, 06:33:06 PM

You sure you don't have a locking relay? How many terminals on the relay? What terminals are you using for the fan? I was assuming you are using a 5 terminal accessory relay.

EMSjunkie · May 28, 2007, 08:04:25 PM

Don't mean to hi-jack the thread, but does anybody have a wiring diagram for a relay?

I need to wire a realy into the secondary fan for the Mrs. S-10.
I have a relay,, just can't remember which numbered post does what :?

any help will be appreciated

Vance

phat46 · May 28, 2007, 08:36:59 PM

Quote from: "enjenjo"You sure you don't have a locking relay? How many terminals on the relay? What terminals are you using for the fan? I was assuming you are using a 5 terminal accessory relay.

I don't believe it locks on normally, when i was testing it off the car it would click closed and open as i applied/removed power to the switch terminals. I had it connected to a light and it funtioned as I thought it should.
It has four terminals on it. 87 and 30 to the fan, 85 positive from switch, 86 to ground.

phat46 · May 28, 2007, 08:38:26 PM

Quote from: "EMSjunkie"Don't mean to hi-jack the thread, but does anybody have a wiring diagram for a relay?

I need to wire a realy into the secondary fan for the Mrs. S-10.
I have a relay,, just can't remember which numbered post does what :?

any help will be appreciated

Vance

Vance, the relay i have has a diagram printed on the side of it, but as you see it didn't help me much..... :oops:

enjenjo · May 28, 2007, 10:41:44 PM

Try it this way. put power on the 30 terminal for the fan, out 87 to the fan. Control power to 85, 86 to the switch, and then to ground. That should solve your problem.

Pep · May 28, 2007, 11:12:51 PM

Is the engine running when you turn on the fan?....will make the diagnosis a bit easier.

Dave · May 29, 2007, 06:56:21 AM

Locking relay? never see one :?: :?: :?: I can make em lock though but it requires a stop and a start switch and a couple extra wires..
Dave

phat46 · May 29, 2007, 03:46:49 PM

Quote from: "enjenjo"Try it this way. put power on the 30 terminal for the fan, out 87 to the fan. Control power to 85, 86 to the switch, and then to ground. That should solve your problem.

O.K. Frank, i'll try it first chance i get and let ya know what happened.

phat46 · May 29, 2007, 03:47:59 PM

Quote from: "Pep"Is the engine running when you turn on the fan?....will make the diagnosis a bit easier.

No, engine not started, key in "run' position.

Pep · May 29, 2007, 08:06:09 PM

OK...after drawing up a little diagram, I think the only way the relay could stay on is if the switch has a slight resistive short across the terminals. Maybe an internal light that supposed to illuminate when the switch is in the on position. The relay will only require a few milli amps to hold on, so any trickle through the switch would do it. Try pulling a wire off the switch when the fan is running and see if it stops. If it does, then my theory is correct.

EMSjunkie · May 29, 2007, 08:54:51 PM

Quote from: "phat46"
Quote from: "EMSjunkie"Don't mean to hi-jack the thread, but does anybody have a wiring diagram for a relay?

I need to wire a realy into the secondary fan for the Mrs. S-10.
I have a relay,, just can't remember which numbered post does what :?

any help will be appreciated

Vance
Vance, the relay i have has a diagram printed on the side of it, but as you see it didn't help me much..... :oops:

Mine too

I guess I don't unnerstand Chinese pictures :oops:

Vance

EMSjunkie · May 29, 2007, 09:01:16 PM

Quote from: "enjenjo"Try it this way. put power on the 30 terminal for the fan, out 87 to the fan. Control power to 85, 86 to the switch, and then to ground. That should solve your problem.

Lemme get this right, before I apply power

Terminal # 30 = input from fan controller
Terminal # 87 = output power to fan
Terminal # 85 = 12V power in from ign. switch
Terminal # 86 = chassis ground

What does #87a do?

I wanna make sure before I turn the key, and the smoke comes outta my new Spal PWM fan control unit.

I'm not sure how much it would cost to have new smoke put back in it, but I bet it ain't cheap

Vance