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

Close, 87a is the N/C terminal which means the relay would turn your fan off when energized. You need to use 87 (N/O) to supply power when energized. An easy way to remember this is that relays with dual outputs (say for a pair of driving lights) have 2x 87 terminals and no 87a.

Ok this confused me a little. what did I get wrong? 87a is wired to the N/C terminal on the relay and 87 to the (n/o) or am I reading this wrong?

30 to battery or F141
87a to N/C on timer
86 ??
85 to ground
87 is wired to N/O on timer

(i know this is wrong but i'm scratching my head here lol)

edit:

or is it the same:

30 to battery or F141
87a to fan motor wire
86 to N/O on timer
85 to ground


but 87 is wired to something to supply power? wired to what? maybe it would help if we put the numbers on the relay in the diagram that way others will know how to wire it up as well.
 
Last edited:
30 to battery or F141 (always hot - if direct from battery needs a 40A fuse)
87 is to fan power wire
86 to N/O on timer
85 to ground

86 supplies the power to close the switch and that current passes from the timer to ground through the relay. That switch in the relay take the power from the battery to the fan power input.

86 is like your finger on the light switch that lets the switch turn on the light with power from 30. It makes contact from 30 to 87.
 
30 to battery or F141 (always hot - if direct from battery needs a 40A fuse)
87 is to fan power wire
86 to N/O on timer
85 to ground

86 supplies the power to close the switch and that current passes from the timer to ground through the relay. That switch in the relay take the power from the battery to the fan power input.

86 is like your finger on the light switch that lets the switch turn on the light with power from 30. It makes contact from 30 to 87.

Alright so nothing is wired to 87a. Got it. :thumbup:

Tomorrow is supposed to be 60 and sunny so i'll get started on this and see if I can blow up the jeep. :)
 
Alright so nothing is wired to 87a. Got it. :thumbup:

Tomorrow is supposed to be 60 and sunny so i'll get started on this and see if I can blow up the jeep. :)

Have fun! Keep in mind though that my question about what the trigger actually controls has yet to be answered. I don't own a timer so I have no way of testing it myself. There is still the possibility that my diagram may need a slight modification on the timer's trigger input. The rest of it will all be the same, I just don't want you to get upset after spending all that time wiring if it turns out your fan runs continuously. It will be a relatively easy fix, it just sucks to have to rewire stuff you just wired...
 
Have fun! Keep in mind though that my question about what the trigger actually controls has yet to be answered. I don't own a timer so I have no way of testing it myself. There is still the possibility that my diagram may need a slight modification on the timer's trigger input. The rest of it will all be the same, I just don't want you to get upset after spending all that time wiring if it turns out your fan runs continuously. It will be a relatively easy fix, it just sucks to have to rewire stuff you just wired...

So if i get this wired up and the fan runs all the time then we go to plan B?

What's plan B?
 
Plan B is to hook the timer up to a momentary switch. The thing I don't like about Plan B is that when you shut down the engine, you'd have to activate the momentary switch to start the fan, it won't be automatic. Keeping my fingers crossed that Plan A works correctly.
 
Plan B is to hook the timer up to a momentary switch. The thing I don't like about Plan B is that when you shut down the engine, you'd have to activate the momentary switch to start the fan, it won't be automatic. Keeping my fingers crossed that Plan A works correctly.

That's not much to ask for IMO. I'd take flipping a switch over a misfire anyday lol. I bought a switch from advance and i happened to pick the wrong one, which is a momentary switch. I didn't want one of those so I popped out the spring inside the switch and now it's a regular switch. I'll put the spring back in and use it if this calls for plan B.
 
Gonna have a slight delay on wiring this up. I was at 8 different stores and no one carried a 40 amp fuse holder. Everyone has 40 amp fuses but no fuse holders. They only go up to 30 amp. What the.....


So i have to order the 40 amp fuse holder online and wait for that to get here before I can do anything.


Unless.....and 30 amp fuse is ok?
 
Gonna have a slight delay on wiring this up. I was at 8 different stores and no one carried a 40 amp fuse holder. Everyone has 40 amp fuses but no fuse holders. They only go up to 30 amp. What the.....


So i have to order the 40 amp fuse holder online and wait for that to get here before I can do anything.


Unless.....and 30 amp fuse is ok?

Yeah, 30A stuff seems to be the norm. Even my Blue Sea Systems fuse box (Rated for 120A total) is only rated at 30A per circuit. Could you use 30A? Honestly, I don't know. I don't know what the power draw is when the fan starts up. I do know the factory protects it with a 40A and seeing as the factory undersizes things whenever possible, I imagine 40A is the proper fuse to use. I'm sure there are folks out there that have used a 30A fuse in this application. Maybe they could provide some insight?

You can still wire a majority of this up today. The fuse should be located as close to the battery as possible. Wire everything else up and run your power wire just short of the battery. When the fuse holder shows up, put it in place and you're good to go. Might as well take advantage of the good weather... :sunshine:
 
Yeah, 30A stuff seems to be the norm. Even my Blue Sea Systems fuse box (Rated for 120A total) is only rated at 30A per circuit. Could you use 30A? Honestly, I don't know. I don't know what the power draw is when the fan starts up. I do know the factory protects it with a 40A and seeing as the factory undersizes things whenever possible, I imagine 40A is the proper fuse to use. I'm sure there are folks out there that have used a 30A fuse in this application. Maybe they could provide some insight?

You can still wire a majority of this up today. The fuse should be located as close to the battery as possible. Wire everything else up and run your power wire just short of the battery. When the fuse holder shows up, put it in place and you're good to go. Might as well take advantage of the good weather... :sunshine:

yeah I'm gonna.

i got a 40 amp circuit breaker from advance and I ordered that 40 amp 8g maxi fuse holder on amazon. So whenever the fuse holder gets here, I'll swap it in place of the circuit breaker. Sound good?
 
An automotive or marine style circuit breaker should be just fine. You could probably even use it instead of the fuse if you wanted... I went with a circuit breaker to protect my aftermarket fuse box.
 
Should be as easy as changing Trigger Mode (Jumper 4) from "B" to "A" so the relay is triggered when power is removed from the trigger terminal. I'm assuming when you say yours is triggered with a 12V "pulse" that you are using a momentary switch to trigger it? If so, the timer should function just the same for you even after switching the jumper. The only difference will be that instead of the delay starting when you push your switch, it will start when you release your switch.

Additionally, if you're already wired up this way, you are set up to answer my other question about whether the trigger controls both the relay and the timer, or just the timer. When you get a chance, switch your Jumper over to "A". Then try holding down your momentary switch and check to see whether or not this immediately starts the fan. Doing this would simulate turning on your ignition using my wiring diagram.

If the fan doesn't come on until you release the momentary switch, my wiring diagram should work as intended. If the fan comes on while you're still holding it down, my diagram needs the trigger reworked to keep the fan from running continuously while the ignition is on.

Mine is wired, as you guessed, with a momentary push-button provide a ‘pulse’ of 12-volt + power.
I tried your suggestion last night to switch the jumper JP4 from 'B' to 'A'.
Unexpectedly, it changed nothing; the fan still starts as soon as the button is pushed. I was surprised, so I tried exchanging jumpers, thinking the JP4 jumper was defective. Also tried switching the Relay Begin and End jumper with no luck.
Maybe my timer if defective, I hope yours works the way you think it should. Time will tell.

The fan relay is wired with 10-gauge wire with an in-line fuse holding a 30-amp ATC/ATO fuse. It has never blown the 30-amp fuse.
BTW, 10-gauge is supposed to be rated for a maximum of 30-amp without significant voltage drop.

Let us know if you figure out how to make the timer turn on when the ignition is turned off. I would still prefer it was wired that way. I would install a three-position toggle switch with the following features

1. Allow the use of the timer,
2. Manually over-ride the timer and run the fan constantly and
3. An 'off' position to limit the electric fan operation to its normal, ECM computer control.
 
Let us know if you figure out how to make the timer turn on when the ignition is turned off. I would still prefer it was wired that way. I would install a three-position toggle switch with the following features
1. Allow the use of the timer,
2. Manually over-ride the timer and run the fan constantly and
3. An 'off' position to limit the electric fan operation to its normal, ECM computer control.
Ask and ye shall receive:

Use an on-off-on type SPDT switch.
Switch in the up position (toggle pointing down) = continuous fan operation
Switch in the center position = OEM operation
Switch in the down position (toggle pointing up) = timer operation

I'm not sure if the diagram has been updated/changed since fyrfytr posted it on page 1, but if it has, I did not add those updates and they still need to be added.
 
Hey guys. I was thinking of adding a fan light on the dash so I know when the fan is running. Is wiring it up as simple as wiring one end of the light to the fan power wire and the other to a ground?
 
Mine is wired, as you guessed, with a momentary push-button provide a ‘pulse’ of 12-volt + power.
I tried your suggestion last night to switch the jumper JP4 from 'B' to 'A'.
Unexpectedly, it changed nothing; the fan still starts as soon as the button is pushed. I was surprised, so I tried exchanging jumpers, thinking the JP4 jumper was defective. Also tried switching the Relay Begin and End jumper with no luck.
Maybe my timer if defective, I hope yours works the way you think it should. Time will tell.

Well, if you're wired up the way I think you are, this is bad news for using the removal of ignition power as the timer starter without having the fan run continuously. If the fan starts running immediately upon pushing and holding the button, this means the trigger kicks the relay on.

Given the above information, switching JP4 from B to A would only have been noticeable if you had your stopwatch out. On B, the timer should have started as soon as you pushed your momentary switch. On A, the timer should have started as soon as you released the switch. Probably only a few seconds difference unless you were holding that switch down for a long time.

Switching BEGIN and END on the other hand should have been noticeable. According the ELK's info, BEGIN turns the relay on when triggered and off when the timer expires. END turns the relay off when triggered and back on when the timer expires. I'm not sure what to tell you if that jumper didn't change anything. :confused:

Now just to clarify since I don't know exactly how your push-button switch works, does it remain closed as long as you hold it in the down position (like honking your horn), or does it momentarily close on the way down and then automatically open itself (like a BBQ igniter)? If it's BBQ igniter style, what I wrote above is incorrect and there is still hope of this working as is...

Oh, and if not, I think there may be a Plan C for ignition operation. I think it involves using the ignition to activate a N/C relay which in turn provides the trigger to the timer. I'm going to have to think about it for a bit...
 
Hey guys. I was thinking of adding a fan light on the dash so I know when the fan is running. Is wiring it up as simple as wiring one end of the light to the fan power wire and the other to a ground?

Getting a little ahead of ourselves, aren't we? Or is your timer working now? :spin1:

I believe you are on the right track. You could even attach the 12V+ side to pin 87 on the new relay if that is more convenient. Attatching it to the N/O ouput on the timer would let you know only when the timer was activating the fan. Before you jump on the dash light idea however, let me remind you of one thing... Your radiator fan continuously cycles on and off whenever you are running the A/C or defroster. Not bad during the day, but annoying at night if it is in your line of sight.
 
X2 on that. If you want to make it dim along with the rest of the dash lights, I believe you could wire the bulb from the fan power line to the dimmer line that feeds all the other dash lights - you'll want to place a diode in line with it, with the cathode (striped end) toward the dimmer line, to keep the dimmer line from backfeeding the e-fan and probably blowing the fuse. I'll see if I can find a color code for the dimmer wire on 97+, I want to say it's red with a black stripe but I'm not sure.
 
X2 on that. If you want to make it dim along with the rest of the dash lights, I believe you could wire the bulb from the fan power line to the dimmer line that feeds all the other dash lights - you'll want to place a diode in line with it, with the cathode (striped end) toward the dimmer line, to keep the dimmer line from backfeeding the e-fan and probably blowing the fuse. I'll see if I can find a color code for the dimmer wire on 97+, I want to say it's red with a black stripe but I'm not sure.

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:
 
Getting a little ahead of ourselves, aren't we? Or is your timer working now? :spin1:

I believe you are on the right track. You could even attach the 12V+ side to pin 87 on the new relay if that is more convenient. Attatching it to the N/O ouput on the timer would let you know only when the timer was activating the fan. Before you jump on the dash light idea however, let me remind you of one thing... Your radiator fan continuously cycles on and off whenever you are running the A/C or defroster. Not bad during the day, but annoying at night if it is in your line of sight.

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.
 
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