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

winterbeater

NAXJA Forum User
OK. Long story (12 pages with 180 posts), short. Mudeprived started a thread for “misfiring, where to buy injectors”. http://www.naxja.org/forum/showthread.php?t=1009745. It has now evolved into a thread on “how to hook a timer up to the efan”. He has a 2001, auto, 4.0, 4WD. :speepin:

I figured we should start a new thread on this after we apparently went the wrong way on the wiring set-up. Joe Peters gave us a link to the wiring for the timer.
http://www.at-fairfax.com/P1786-ELK-960.htm

On the 2001 XJ (as many may already know), the efan is powered by a relay that is fed by a 40A fuse. That fuse is always hot to the relay. The relay is activated by the PDC completing ground for the relay activation circuit. That side is only hot when the key is in RUN or ACC.

I thought from previous threads that you just needed to splice into the ground side of that circuit after the relay with a switch or timer switch to activate the fan. It seems obvious to me that won’t work because the power feed is off when the key is off.

The best way I can see to do it is to run a relay parallel to the factory relay, which would be activated by the timer for the length of time you wanted. The relay in the timer itself is rated for 7 amps @ 30 volts, IIRC, that would be the same as 17.5 @ 12 volts. Not enough for the efan on the 40 amp fuse.

I’ve tried searching this myself without much success. I know this has been done before. There has also been advice on needing a diode to stop the CEL light. This made sense to me if you could activate the factory relay with a switch, but that seems impossible, as there is no current to the activation side of the relay with the key off.

Any other ideas on this? :huh:
 
I can think of a couple ways depending on how that module works. Any design would have to use a 5-pin relay that switched between power inputs based on presence of ignition power. IE, if ignition power is hot then the selector relay is active on one input that draws from another ignition source, but when ignition power is off the relay switches to the other input which would have the timer and a battery power source.

If that module allows for something like "run for 60 seconds after input power disappears" then nothing else is needed--just watch for power to the fan, and if ignition power dies switch over to battery power under timer control.

An aftermarket temperature switch would probably be simpler, since you can make the switch run all the time, and then the timer just needs to maintain power for ~60 seconds and can cut off (rather than switch between the power supplies). This won't work with ECM controlled fan because the ECM switch disappears when ignition power goes off. You could probably use the headlight delay timer the same way, since it is designed to operate with constant battery power feeding the headlights. So just setup the fan delay timer the same way, using a headlight timer, or using the module, whichever works.
 
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If you look at the very nice wiring diagram fyrfytr1717 has included, you can see that the trigger side of the relay is powered only in RUN/START key position. You can turn the fan on manually while the Jeep is running. We want to kick it on after the Jeep is turned off to cool of the engine bay/fuel rail/fuel injectors for better hot restart.

That is an excellent write up for what he is doing, but I don't think it works for us.
 
I looked at the FSM notes for the headlight delay module, and it seems pretty straightforward. Basically if ignition power is turned off first, followed by headlight power turned off, then a timer is started. I imagine that there are a couple of relays inside the module, with the output power coming from the headlight switch and battery hot, and then feeding into headlight relays in the PDC. Here's a picture of one I found for sale.

a20791612610c5b1077c6f_m.JPG


I imagine this could be setup the same way with an aftermarket fan switch that was wired to battery hot.
 
Has anyone though of using a thermistor in place of this timer thing.

Basicly, a thermistor is just a bi-metal sensor that will go to gound when a certain ambient temp is exceeded. It would supply the ground for the relay and turn it'self on/off only when set temp is exceeded. So the faan would only run after x temp is exceeded after shutoff. Would also turn it'self back on if temp was again exceeded.

Volkswagons use this exact system to run the electric fan after shutoff in Jetta's and Golfs after '92.

Just an idea.
 
I have used a fan timer for over a year and a half with no problems
http://www.flickr.com/photos/lwade/sets/72157617434915718/
Before I installed the timer, I had previously added a switch, an inline 30-amp fuse and a 5-pin Bosch-type 40-amp relay wired to allow manual activation of the electric fan, when the ignition was on.

When the timer was added, I used the same fan relay, adding a couple of diodes to prevent any back feeding of power into the ignition circuit.

The diodes are located in the added fan relay's trigger wires, coming from the fan switch and timer.

If you zoom in on the photo in the link below, you can see the timer's
6 terminals.
http://www.at-fairfax.com/P1786-ELK-960.htm


The timer's "+" terminal feeds off a fused, always hot connection.

The activation button feeds power from the "+" terminal to the "trigger" terminal, starting the timing cycle.
The same always-hot power supply also feeds the "common" terminal. The "NO" terminal (normally open) feeds the added fan relay's coil.
The timer can be activated at any time with the ignition on or off.
Wish I had a program to draw the schematic; it's really simple.
 
If you look at the very nice wiring diagram fyrfytr1717 has included, you can see that the trigger side of the relay is powered only in RUN/START key position. You can turn the fan on manually while the Jeep is running. We want to kick it on after the Jeep is turned off to cool of the engine bay/fuel rail/fuel injectors for better hot restart.

That is an excellent write up for what he is doing, but I don't think it works for us.

Yeah, no timer on mine and it only works with the ignition in Run/Start. (No heat soak issues on my '99) The Jeep doesn't have to be running, but the key has to be left in the ON/RUN position. It would work, but you wouldn't want to turn it on and walk away.

Seems to me this should be easy to wire up so long as that timer can be triggered by power being taken away from it. You'd wire up a separate power supply to the fan (through a relay) and have that relay activated by the timer. Any given ignition switched 12V+ of your choice could be hooked up to the trigger terminal on the timer. The removal of this ignition switched 12V+ would be your "trigger" any time the ignition switch was turned off.
 
OK, here we go. I'm about 99% sure this is going to work correctly. I've taken info from all three of the threads and combined them to come up with the following wiring diagram. Now that I know we are in fact using the ELK-960 Delay Timer Module, I have something to work off of. This is essentially what the ELK tech guy told you (muddeprived) to do, with the addition of a relay to handle the power draw of the Radiator Fan. This is based off the wiring diagram from the FSM so part of the factory circuit is omitted. Hopefully it is big enough for you to make out.

AuxFanDelayTimerWiring.jpg


Basically, we are creating a second fan control circuit using a New Relay. I'd recommend installing the relay in the engine compartment to cut down on the length of the heavier gauge power wire. The rest of the wiring can all be done with small gauge wire as the power draw of the relay coil and the timer module are very low.

One side of the New Relay gets tied to the battery using large gauge wire (the factory uses 12g, I'd recommend 10g). The other side gets tapped into the positive lead on the Radiator Fan, again using large gauge wire. If you tap into BATT F141 as shown in my diagram, you can leave out the fuse. If you connect directly to the battery, install an in-line 40amp fuse.

One side of the New Relay coil gets connected to a convenient ground. The other side gets connected to the Normally Open (N/O) terminal on the Delay Timer. If you are installing the Delay Timer in the passenger compartment, this wire will have to run from inside the vehicle, through the firewall, and out to the New Relay in the engine compartment.

The Positive (+) terminal on the Delay Timer gets tapped into a Constant 12V+ source. There are a few to choose from in the passenger compartment and all of them should already be fused by the factory system.

The Negative (-) terminal on the Delay Timer gets connected to a convenient Ground.

The Trigger (TGR) terminal gets tapped into an Ignition Switched 12V+ source. Doesn't matter what it is really, so long as it is hot when the ignition is on and dead when the ignition is off. Again, this should already be fused by the factory system.

The Common (COM) terminal simply gets jumped over to the Positive (+) terminal. This is where the Delay Timer's built in relay gets the power to send out through the N/O terminal.

That's it for the wiring. An easy place to access both a constant 12V+ and an ignition switched 12V+ would be at the switch panel below the HVAC controls. Red w/ Light Blue tracer on the back of the Power Outlet is constant. Solid Red on the back of the Cigar Lighter is ignition switched (technically Cigar Lighter Relay switched). The positive wire on the Radiator Fan should be a Light Blue 12g wire. The BATT F141 wire is Light Green w/ Red tracer 12g wire but can only be found within the PDC housing. These colors are all based on my '99 FSM, but I believe they are the same '97-'01.

As for the Delay Timer's jumper settings:
Jumper 1 gets set to "MIN" so you can run the fan for more than 60 seconds.
Jumper 2 gets set to "1-SHOT" so it doesn't continue to cycle on and off after the delay is over.
Jumper 3 gets set to "BEGIN" so the built-in relay turns ON when triggered.
Trigger Mode (Jumper 4) gets set to "A" so the relay is triggered when power is removed from the trigger terminal.
Trigger Polarity (Jumper 5) gets set to "+" as we are using an ignition switched 12V+ source as the trigger.
R3 gets set to the desired number of minutes (1-60) you want the fan to run.

The ELK-960 information also mentions that it automatically runs through a cycle when first powered up. I don't know for sure whether this means when the (+) terminal is first connected, or each time the (TGR) terminal is supplied with power. If it's the latter, be aware that your fan will run for the set amount of time each time you turn on your ignition. Hopefully this is not the case.

Well that about wraps it up. Hopefully this is fairly easy to understand and my diagram is at least somewhat legible at that size. Please post your results if you wire it up using the above instructions. I have no plans to use this mod myself as I have no heat soak issues, but would like to know for sure that this works correctly. Thanks! :wave1:
 
Reading through the ELK-960 materials again, I can't tell for sure whether the trigger (removal of the 12+ on the TGR terminal) activates the relay and starts the timer, or whether is just starts the timer. If it only affects the timer, this could cause the fan to run continuously, shutting off only at the set amount of time after you turn off the ignition. Can someone that owns one of these timers test this for me? I believe there is an LED on the board that indicates relay status.
 
Nice work, it looks like it should work fine.
A couple of suggestions.
The timer is not needed in cold weather so consider adding a switch in the constant 12-volt '+' wire going to the timer to shut it off when it is not wanted.
A manual over-ride switch is a good addition for off-roading. Combining the timer and manual over-ride, using the same relay, is where I found that a diode was needed to keep the timer from back-feeding the ignition circuit (which blew the 5-amp inline fuse installed in the constant '+'wire going to the timer). A diode was also needed in the wire coming from the trigger button to the timer.

I think I will try wiring the trigger using the switched 12-volt power, the way you did, and also add an on/off-switch.
For six months of the year, vapor locking is not a problem.
In the warm months, it’s always a problem so having the fan automatically come on every time the engine is turned off is good.
 
Reading through the ELK-960 materials again, I can't tell for sure whether the trigger (removal of the 12+ on the TGR terminal) activates the relay and starts the timer, or whether is just starts the timer. If it only affects the timer, this could cause the fan to run continuously, shutting off only at the set amount of time after you turn off the ignition. Can someone that owns one of these timers test this for me? I believe there is an LED on the board that indicates relay status.

Mine is triggered by energizing the relay's trigger with a positive 12-volt pulse. I do not have the timer's instructions on hand, what dip switch(s) needs to be changed to allow the removing of 12-volt power to trigger the timer.
I can give it a try, maybe, in the next couple of days if time permits.
 
OK, here we go. I'm about 99% sure this is going to work correctly. I've taken info from all three of the threads and combined them to come up with the following wiring diagram. Now that I know we are in fact using the ELK-960 Delay Timer Module, I have something to work off of. This is essentially what the ELK tech guy told you (muddeprived) to do, with the addition of a relay to handle the power draw of the Radiator Fan. This is based off the wiring diagram from the FSM so part of the factory circuit is omitted. Hopefully it is big enough for you to make out.

AuxFanDelayTimerWiring.jpg


Basically, we are creating a second fan control circuit using a New Relay. I'd recommend installing the relay in the engine compartment to cut down on the length of the heavier gauge power wire. The rest of the wiring can all be done with small gauge wire as the power draw of the relay coil and the timer module are very low.

One side of the New Relay gets tied to the battery using large gauge wire (the factory uses 12g, I'd recommend 10g). The other side gets tapped into the positive lead on the Radiator Fan, again using large gauge wire. If you tap into BATT F141 as shown in my diagram, you can leave out the fuse. If you connect directly to the battery, install an in-line 40amp fuse.

Can I use 12g instead of 10g? The timer ports for the wire ends are very small and 10g doesn't fit in it. How do I access Batt F141 that's inside the PDC?

One side of the New Relay coil gets connected to a convenient ground. The other side gets connected to the Normally Open (N/O) terminal on the Delay Timer. If you are installing the Delay Timer in the passenger compartment, this wire will have to run from inside the vehicle, through the firewall, and out to the New Relay in the engine compartment.

Is this right on the relay?

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

The Positive (+) terminal on the Delay Timer gets tapped into a Constant 12V+ source. There are a few to choose from in the passenger compartment and all of them should already be fused by the factory system.

The Negative (-) terminal on the Delay Timer gets connected to a convenient Ground.

The Trigger (TGR) terminal gets tapped into an Ignition Switched 12V+ source. Doesn't matter what it is really, so long as it is hot when the ignition is on and dead when the ignition is off. Again, this should already be fused by the factory system.

The Common (COM) terminal simply gets jumped over to the Positive (+) terminal. This is where the Delay Timer's built in relay gets the power to send out through the N/O terminal.

That's it for the wiring. An easy place to access both a constant 12V+ and an ignition switched 12V+ would be at the switch panel below the HVAC controls. Red w/ Light Blue tracer on the back of the Power Outlet is constant. Solid Red on the back of the Cigar Lighter is ignition switched (technically Cigar Lighter Relay switched). The positive wire on the Radiator Fan should be a Light Blue 12g wire. The BATT F141 wire is Light Green w/ Red tracer 12g wire but can only be found within the PDC housing. These colors are all based on my '99 FSM, but I believe they are the same '97-'01.

As for the Delay Timer's jumper settings:
Jumper 1 gets set to "MIN" so you can run the fan for more than 60 seconds.
Jumper 2 gets set to "1-SHOT" so it doesn't continue to cycle on and off after the delay is over.
Jumper 3 gets set to "BEGIN" so the built-in relay turns ON when triggered.
Trigger Mode (Jumper 4) gets set to "A" so the relay is triggered when power is removed from the trigger terminal.
Trigger Polarity (Jumper 5) gets set to "+" as we are using an ignition switched 12V+ source as the trigger.
R3 gets set to the desired number of minutes (1-60) you want the fan to run.

The ELK-960 information also mentions that it automatically runs through a cycle when first powered up. I don't know for sure whether this means when the (+) terminal is first connected, or each time the (TGR) terminal is supplied with power. If it's the latter, be aware that your fan will run for the set amount of time each time you turn on your ignition. Hopefully this is not the case.

If it is the latter, it doesn't seem to be a big issue to me. One or two minutes on start up wouldn't harm much.

Well that about wraps it up. Hopefully this is fairly easy to understand and my diagram is at least somewhat legible at that size. Please post your results if you wire it up using the above instructions. I have no plans to use this mod myself as I have no heat soak issues, but would like to know for sure that this works correctly. Thanks! :wave1:

Thanks for everything man. That was perfect for my noobish arse lol. Let me know about the questions above and then I'll get started on this as soon as it stops raining.

:yelclap:
 
Thanks fyrfytr1717. I was going to try to draw it up like that, but didn't do it yet. Very clear instructions.

I was thinking of just adding a pushbutton to the consol to activate the timer instead of having it kick on every time. The trigger can be set either to fire when power is removed OR introduced. You could also kick it on while driving. I suppose that would get us back into adding a diode.
 
Thanks fyrfytr1717. I was going to try to draw it up like that, but didn't do it yet. Very clear instructions.

I was thinking of just adding a pushbutton to the consol to activate the timer instead of having it kick on every time. The trigger can be set either to fire when power is removed OR introduced. You could also kick it on while driving. I suppose that would get us back into adding a diode.


How would you wire up a switch or push button with this setup?
 
Can I use 12g instead of 10g? The timer ports for the wire ends are very small and 10g doesn't fit in it.

12g should probably be fine, that's what the factory uses. Just keep the wiring run as short as possible.

How do I access Batt F141 that's inside the PDC?

Not very easily, you'd have to actually open up the PDC housing which involves a whole bunch of frustrating snaps and clips. If I were doing this, I'd probably just do the inline fuse thing. A small ATC fuse holder is cheap and easy to stash somewhere. Most auto parts places only have ATC fuses up to 30A, but Radio Shack usually has 40A in stock. A larger Maxi fuse would probably be ideal, but the holders are a little more expensive.

Is this right on the relay?

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

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.

Here is my favorite relay info site: http://www.bcae1.com/relays.htm

If it is the latter, it doesn't seem to be a big issue to me. One or two minutes on start up wouldn't harm much.

Yeah, probably true, just thought it might be annoying and would cause your engine to warm up slower.

Thanks for everything man. That was perfect for my noobish arse lol. Let me know about the questions above and then I'll get started on this as soon as it stops raining.

:yelclap:

No problem, I actually enjoy trying to figure this stuff out and then making it as easy to understand as possible.
 
Mine is triggered by energizing the relay's trigger with a positive 12-volt pulse. I do not have the timer's instructions on hand, what dip switch(s) needs to be changed to allow the removing of 12-volt power to trigger the timer.
I can give it a try, maybe, in the next couple of days if time permits.

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.
 
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