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How can I hook up an efan timer on a 2001?

Dimmer on a 97+ is solid orange. I know you're the electrical guru here, but would hooking the light up between the fan's 12V+ power line and the dimmer's variable + power line really work? Don't you need a ground? Do you hook it up to the fan's - wire? Or would the difference in voltage between the two power wires cause the light to illuminate? I have so much to learn about electricity.... :confused:
The dimmer circuit is a wacky one... it ranges from 12 to 0 volts. The higher the voltage gets, the lower the lights are supposed to go (at least on a 96-, I'm almost certain it's the same 97+ but I left my 97 FSM at work.) So connecting the bulb from the +12 on the fan to the dimmer circuit results in it grounding through the dimmer circuit. You can view the dimmer circuit as a ground that just happens to get lousier and lousier the dimmer the lights are supposed to be.

The only bad thing that could happen is if the fan is off and the lights are fully dimmed, which would put 12 volts on the dimmer line and backfeed through the bulb to the fan if you don't put in a diode between the "fan on" indicator and the dimmer line, with the cathode connected to the dimmer line.
 
The dimmer circuit is a wacky one... it ranges from 12 to 0 volts. The higher the voltage gets, the lower the lights are supposed to go (at least on a 96-, I'm almost certain it's the same 97+ but I left my 97 FSM at work.) So connecting the bulb from the +12 on the fan to the dimmer circuit results in it grounding through the dimmer circuit. You can view the dimmer circuit as a ground that just happens to get lousier and lousier the dimmer the lights are supposed to be.

Interesting, learned something new here. I'm going to have to experiment and see if I can get my winch power indicator light to work like this. It's pretty darn bright at night.
 
Well if I'm gonna wire this up I might as well get it all done at once so I'll add a light to it.

i don't use my AC or heat/defrost so the fan usually has a layer of dust on it lol. Light won't be on much really. I just want to make sure it's not on all the time, like a malfunction with the timer or something.

You're going the opposite way that I would. I'd be hooking up the relay first and make it works when the trigger is activated. Then I would add the timer in. Then I would add the light.

If you get this whole thing in and it doesn't work the first time (estimate 60% likelihood) due to a bad connections, mis-chosen wire, whatever, then you have to start from the beginning troubleshooting.

Go step by step and make sure that each stage works. Plus, you get a little thrill when each step actually works.
 
Alright I hooked it all up and tested it. When I first connected the battery the fan turned on.......for 30 seconds. :guitar: That got me excited cuz it's actually working LOL. i started it and shut it down....and it stayed on for another 30 seconds again. Sweet!

But the fan runs continuously when the motor is running so what do I gotta do to keep the fan from running while the jeep is running?
 
I changed JP4 to "B" and tried it. When I initially hooked up the battery, the fan ran for 30 seconds and shut off. When I started the jeep, the fan ran for 30 seconds and shut off. When I shut down the jeep, the fan doesn't run. Weird.
 
I also pulled the oem fan relay while the jeep was running and the fan stayed on. Dunno if that means anything........

This is the relay I'm using:

http://shop.advanceautoparts.com/we...uct_Relay-BWD_3993310-P_1010_R|GRPRELAAMS____

Here are some pix of the setup. Let me know if you see anything wrong.......

(this is gonna be covered with a big wire loom)
DSCF7127.jpg


down under the snorkel and hidden..

DSCF7129.jpg


another loom with 6 wires skippin across the engine bay....

DSCF7128.jpg


The web of wires that I need to fix up and make look a little more neater...

DSCF7130.jpg

DSCF7131.jpg


circuit breaker as close to the battery as I could get it. The fuse before it is for my aftermarket heater
DSCF7132.jpg


where i'm gonna mount the timer after everything is fixed..
DSCF7134.jpg


Tappin into the fuses. Gotta love those fuse taps..
DSCF7135.jpg


That's about it. I want to fix up all those red wires going to the relay on the firewall cuz it looks a little out of place. Any tips on how to fix that up are welcome. :)
 
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Your wiring looks pretty good. I'm impressed. Now to get it all working like you want. I would go in little steps. Seems like it runs all the time basically.

If you disconnect the wire from the relay to the timer, does it turn off? Then you hook it back up to the timer and the fan runs?
 
Your wiring looks pretty good. I'm impressed. Now to get it all working like you want. I would go in little steps. Seems like it runs all the time basically.

If you disconnect the wire from the relay to the timer, does it turn off? Then you hook it back up to the timer and the fan runs?


Thank you. I wired up a few rockcrawlin RC's before so I have a little experience in that but understanding how all that stuff works is not my strong suit (but i'm improving!).

I started the jeep and disconnected terminal 86 and the fan shut off. I reconnected it and the fan started up again.

AuxFanDelayTimerWiring1.jpg
 
Next diagnostic test.............What happens if you have the TIMER TRG disconnected? Does it still keep running? Does it just run for a short time and then stop?

I started it up and the fan was running so I disconnected the trigger and the fan shut off. It took like 3-5 seconds for the fan to come to a complete stop. Does this tell ya anything?


While the trigger wire was disconnected, I tapped the trigger wire to the trigger terminal and the timer LED light popped on and fan stayed on for 10 seconds (with trigger wire disconnected still). I tapped the terminal again and same thing, 10 second fan. (i have the timer set for 10 seconds). So basically when the trigger wire contacts the trigger terminal it starts the timer whether it stays connected or not.
 
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So here's the problem... you just confirmed it before lazyxj had a chance to get back to me on his switch. The original idea was to make it so that the timer was triggered when the ignition was shut off. Setting Jumper 4 to A told the timer to start when (ignition switched) voltage was removed from the trigger. The problem is, regardless of the setting of Jumper 4, the built in relay was being activated (thus turning on the fan) as soon as the trigger wire received power from the ignition. As I mentioned earlier in the thread, the info provided by ELK wasn't very clear on whether the trigger activated just the timer, or both the relay and timer.

What is happening is that when you turn on the ignition, the relay is being activated by the application of 12V+ at the trigger terminal. It stays on because Mode A is waiting for this voltage to disappear before starting the timer. As soon as the ignition is turned off, the timer is triggered and the built-in relay shuts off when the countdown is over.

The easy solution is to attach the trigger wire to a momentary switched 12V+ source. When you want the fan to run a timed cycle, you hit the momentary switch and the fan runs for however long you set the timer for. (You just proved this works when you were tapping the trigger terminal with the trigger wire.) The only problem with this is that the fan does not turn on automatically as was originally desired.

I guess the next question is how badly do you want it to run automatically? It would involve including another relay in the circuit. It could be placed right next to the timer as all the necessary wires would be available there. I'm at work so I can't draw it out right now, but here's how it would go:

"Plan C"

The current trigger wire would be disconnected from the timer and re-connected to terminal 86 on this additional relay.
Terminal 85 would be connected to ground.
Terminal 30 would be connected to your constant 12V+ source.
Terminal 87a (N/C) would be connected to the trigger terminal on the timer.
Trigger Mode (Jumper 4) would be switched to Mode B.

Here's how it would work:

When you turn your ignition on, this additional relay would take power away from the trigger terminal on the timer. This would prevent the built-in relay from turning on. The fan would run only when the PCM told it to.

When you turn the ignition off, this additional relay would apply power to the trigger terminal. With J4 set to B, this application of power would trigger the relay to turn on and start the timer. The timer would do it's countdown and shut off the built-in relay when it hit zero. The trigger would still have 12V+ on it, but the timer would prevent the relay from staying on.

There may be a cleaner way, but if there is I can't think of it right now. I don't particularly like the complexity of having 3 relays in the system, but it's the only way I can see it working automatically.
 
Ok thanks for getting back to me with some great info. I actually understand what you are saying. I don't mind running a momentary switch to the trigger and just activate it when I turn off the jeep. The e-fan is barely ever running under normal driving conditions cuz the temp never reaches the set temp for the e-fan to kick on so it's basically "useless" at this point in time. I also never touch the AC or heater either so those never trigger the fan on. So if I hook up a switch, I just push it when I turn off the jeep (when I feel it's needed) and fan kicks on. My question is how do I wire up a switch? Do I just put the switch inline with the trigger wire? i don't know how many terminals the the switches have. Do i have to run one terminal to ground or just one end of the trigger wire on one terminal and the other end on the other terminal?

One last question, do i need to use 12g wire for the 2nd relay or can I just use the 16g all around? (i ran out of 12g so i'll buy more if needed)

I understand plan C just fine, no diagram needed for that. I want to try the switch first and see how that works so let me know how to wire that up and i'll give it a try.






So here's the problem... you just confirmed it before lazyxj had a chance to get back to me on his switch. The original idea was to make it so that the timer was triggered when the ignition was shut off. Setting Jumper 4 to A told the timer to start when (ignition switched) voltage was removed from the trigger. The problem is, regardless of the setting of Jumper 4, the built in relay was being activated (thus turning on the fan) as soon as the trigger wire received power from the ignition. As I mentioned earlier in the thread, the info provided by ELK wasn't very clear on whether the trigger activated just the timer, or both the relay and timer.

What is happening is that when you turn on the ignition, the relay is being activated by the application of 12V+ at the trigger terminal. It stays on because Mode A is waiting for this voltage to disappear before starting the timer. As soon as the ignition is turned off, the timer is triggered and the built-in relay shuts off when the countdown is over.

The easy solution is to attach the trigger wire to a momentary switched 12V+ source. When you want the fan to run a timed cycle, you hit the momentary switch and the fan runs for however long you set the timer for. (You just proved this works when you were tapping the trigger terminal with the trigger wire.) The only problem with this is that the fan does not turn on automatically as was originally desired.

I guess the next question is how badly do you want it to run automatically? It would involve including another relay in the circuit. It could be placed right next to the timer as all the necessary wires would be available there. I'm at work so I can't draw it out right now, but here's how it would go:

"Plan C"

The current trigger wire would be disconnected from the timer and re-connected to terminal 86 on this additional relay.
Terminal 85 would be connected to ground.
Terminal 30 would be connected to your constant 12V+ source.
Terminal 87a (N/C) would be connected to the trigger terminal on the timer.
Trigger Mode (Jumper 4) would be switched to Mode B.

Here's how it would work:

When you turn your ignition on, this additional relay would take power away from the trigger terminal on the timer. This would prevent the built-in relay from turning on. The fan would run only when the PCM told it to.

When you turn the ignition off, this additional relay would apply power to the trigger terminal. With J4 set to B, this application of power would trigger the relay to turn on and start the timer. The timer would do it's countdown and shut off the built-in relay when it hit zero. The trigger would still have 12V+ on it, but the timer would prevent the relay from staying on.

There may be a cleaner way, but if there is I can't think of it right now. I don't particularly like the complexity of having 3 relays in the system, but it's the only way I can see it working automatically.
 
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By the way, my fan is very loud. It runs like a little lawnmower motor. :laugh2: I was thinking of replacing it with an aftermarket e-fan that runs quieter. Any recommendations? (it's loud enough that it feels like the jeep is actually running when the ignition is off LOL)
 
I played around with a swtich. I wired it up inline with the trigger wire. There is only two terminals on the momemtary switch so I just cut the trigger wire and put the switch in the middle and connected the two ends. I can switch on the fan as I please when the jeep is running but it doesn't work when the jeep is off, which defeats the purpose of it. Did I wire up the switch wrong?
 
Now that we see exactly how the timer works, all you need to do is put a momentary switch in. Personally, I think a push button would be the coolest. You couldn't break it off. If it seems to be getting hot when driving rough terrain or towing (or whatever), you just hit the button and the fan will kick on for your preset time. Or you can just hit the button when it's a little warm and you stop. Light wire is fine for any of the timer/relay activation. You only needed heavy wire going to the fan motor itself.

Seems like you've got it now. I think a lot of people will be bookmarking this thread.

Thanks to fyrfytr1717 for leading us through this. party1:


Whoops, I see from you latest post that I started the party too early.

Your timer trigger wire is always hot isn't it. 12V even with key off?
 
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Thinking about it now, that is what is wrong. We were trying to make key off trigger the timer. Now we have changed to plan B or C. With a momentary switch, we want to be hot all the time. It still should be fused, so a good source would be the power outlet plug in the dash.
 
Thinking about it now, that is what is wrong. We were trying to make key off trigger the timer. Now we have changed to plan B or C. With a momentary switch, we want to be hot all the time. It still should be fused, so a good source would be the power outlet plug in the dash.

Ok so If I understand you correctly, right now I have the trigger set on an ignition switched 12v fuse (fuse tap). This is why it's not working. I need to scratch that wire and instead wire it up to a constant 12v fuse and put the switch inline with that. Right?

I have the Postive and Com terminal wired to a constant 12v fuse as well. I leave this alone right? It doesn't matter if the trigger, positive, and com terminals are all wired to constant 12v?
 
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