winterbeater
NAXJA Forum User
- Location
- Royal Oak, Michigan
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 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: