Rods2ndxj

I have recently acquired a 2000 XJ, have to get it emission checked and check engine light is on. It will not pass with the light on. I used a code scanner and the message says P1491 - Radiator fan relay control circuit. I can reset the codes, but the check engine light comes right back on at next start. I assume the auxilary fan was plugged into the wiring loom somewhere, but is now bypassed. The fan is now wired to a different relay (says Ford on it) atttached to the inside of the passenger fender under the hood, with wiring ran thru the firewall to the inside and has a switch attached to manually turn it off and on.

My question is, where was the fan originally plugged in and can it be jumper-ed or something to get rid of the code and keep the check engine light off?

fb97xj1

Do you get the light with the relay removed?

Rods2ndxj

I don't know if the relay is still installed. I've seen different posts of it being on the left or right inner fender. Do you know definitively where it is on the 2000 Cherokee Sport?

fb97xj1

Should be listed on the inside of the PDC cover. I forgot, there is a fuse too.

Attachment 303281

Rods2ndxj

Thanks fb97xj1 for the tip. In that box under the hood, there is a socket for the cooling fan relay (closest to the firewall). The relay that was added (attached to the passenger fender) is the same relay that fit in the socket that was in the fuse block under the hood. I plugged it in there, cleared the code and the check engine light stayed off. So I think I'll just get another relay to leave plugged in the fuse box.

Can you think of any reason not to plug in the relay in the fuse box and have the other one plugged in, both at the same time? It looks like the added relay and switch are directly wired off the battery, but plugged into a fuse in the box on the inside. I'll post a couple of pics.

Rods2ndxj

Fan, grounded to body, red wire goes over to relay.

Yellow wire on left is red wire coming from the fan. The red wire here goes to the positive terminal on the battery. The yellow wire at the top of this picture goes to thru the firewall to the fuse box on the inside and to the rocker switch.

I pulled the relay out of the socket attached to the fender and plugged it into the fuse box socket under the hood (at the top of this pic).

Red wire here, connected to the fuse block where there is no fuse, is the wire coming from the relay attached to the fender under the hood.

freegdr

Other relays there because there a issue with that circuit .

Rods2ndxj

freegdr, so they should be on two different circuits, correct?

Would it hurt to have both relays plugged in? The check engine light comes on if there is not one plugged into the socket in the PDC.

Rods2ndxj

So another dilema...because I didn't have another relay for both sockets (PDC & added fan relay circuit) the auxilary fan was not running and it overheated. Check engine light did stay cleared with relay installed in PDC socket and passed emission inspection. Bought new relay and installed it, but now AC clutch will not kick on. Tried adding freon with one of the diy cans from O'Reilly, determined it had more than enough pressure but no cold air.

Any thoughts where to start troubleshooting this one?

scorpion66772

Behind the fuse box you have been dealing with under the hood you have your AC accumulator with a grey plug with 2 wires coming out of it.. Put a jumper wire in between those 2 wires and then see if the ac fan comes on when the ac is on..

Rods2ndxj

It's the clutch on the compressor that is not coming on.

scorpion66772

The ac system works on a series circuit, like old school christmas lights where if one goes out they all go out. You mentioned he wired into the ac fan. If the wire was cut and by the look of the pic it is, then NOTHING will work the factory wire will be coming out from under you air filter.. Try to rewire that first .. It has to detect the accumulator, then detect the fan, then the compressor.. you cant just rewire the fan and expect it to work.. I only go into the ac system info because it is also you hi-temp fan.. It will kick on when the engine gets too hot to cool it back down.

Rods2ndxj

Thanks for the info, scorpion66772. My previous XJ was an '89 limited. There was a thermostat switch in the radiator that controlled the aux. fan. When it went out, I just hotwired it to run all the time. Apparently the AC was not dependent on it running and was controlled only by radiator water temp. Sounds like I have a lot more troubleshooting to do. Haven't had time to get to it just yet, but I'll post back when I do. Thanks again!

Rods2ndxj

I wired the aux fan back into the factory plug with jumper wires. At this point the compressor clutch would come on for just a few seconds then go off. So I connected one of those diy refrig cans and got enough freon in it for the clutch to stay on for about a min or more and continued to dump the rest of the freon in the system. But then the clutch kicked off and it quit blowing cold air. The pressure on the diy gauge got to about 70-100psi so I tried bleeding it off of the high side. The pressure would climb back up after I bled some off. I got the rest of the freon into the system with the end pressure at about 50psi. The ac compressor clutch never came back on and tghe ac did not blow cold air anymore. The aux fan never came on so when temp gauge on the dash got slightly above 210, I plugged the added relat back in so I could turn on the aux fan so it wouldn't overheat. Thoughts?

Rods2ndxj

FYI: I jumpered the accumulator connector and the compressor clutch runs. Still with the aux fan connected to factory plug under air cleaner box.

Bad accumulator? Replace it?