92 XJ Jeep cooling fan fan relay issue

[XJRex1]

8/13/15Ok -thank you to all who responded-BUT-nice way puttin it- I'm frustrated at least---swapped relays-reinstalled old fan temp sensor-NO CHANGE-still throws in Code 35- just not gettin it -dont know if fan will come on at 220-230 range (cant get her to go much past 210) BUT fan DOES come on with a/c - there's a fox in the hen house somewhere - - HELP
8/10/15
Yeah I’m in trouble - Help Please, if ya have a minute.*have a 1992 XJ 4.0 - cooling fan had locked up - installed new fan - it wouldn't come on with a/c or at 220-230 degrees - checked Codes got 55 - replaced Coolant Temp Sensor at Thermostat - fan stil didn't come on - after that the Code came up 35 - checked relay - it was good but 20 amp fuse before it had blown - replaced 20 amp fuse - fan came on with a/c BUT getting Code 35 - have 4 Ar272 3087 Relays all test good - stil Codes 35 - not sure how fix this & get back to Code 55 as should be. Have disconnected battery more than once to reset computer.
Thank you , Rex : [email protected] 614-306-0871

[NW99XJ]

Sometimes relays can test fine on a bench (out of the vehicle) but then IN the vehicle, there may be a voltage/ground/continuity issue that causes the relay to not function properly.
I know in the late models, that merely disconnecting the battery wont reset the computer.
There is a procedure, and I believe it;='s the same for the older models.

Disconnect the positive battery terminal.
(leaving the ground/negative side hooked up)
Take the battery cable from the positive side, and hold it to a good ground for several seconds. Ensure that its a bare metal surface, free of paint, grease, and dirt. What this does is completes the circuit, causing a short... the remaining voltage in the system bleeds out, not having any other voltage to feed the short.
Once this is done, leave the cable disconnected, and head inside the jeep.
With the positive still disconnected, turn the key all the way on, (not to start tho)
then cycle the headlights. What we have done is turn virtually every circuit in the Jeep to "on" and cycling the largest amp draw in the system will ensure there is ZERO residual voltage left in the system, completely wiping the memory clean.
You may now hook up the battery. (would be a good time to do some battery maintenance if you have a need for it)
The Jeep will default to a pre-set map for the operating parameters, which may provide less than desirable performance, until all the sensors have read enough information to re-write the map program. In some cases, this could be up to 50 heat cycles, but I have never seen it take that long.

I would also try playing musical chairs with the relays, swap them around in different configurations, see if that does anything.

Worst case scenario you may have to wire this one up yourself.
Wouldn't be too hard...you'd prob have to buy an aftermarket fan controller like this one from Amazon for under $40, but wiring it in is fairly simple.
Amazon.com: Derale 16738 180 Degree Farenheit Single Stage Electric Fan Controller: Automotive@@AMEPARAM@@http://ecx.images-amazon.com/images/I/51X4yxBLTZL.@@AMEPARAM@@51X4yxBLTZL

http://ecx.images-amazon.com/images/I/71iOgipn8IL._SL1500_.jpg

Hope this helps. Good luck,

[XJRex1]

thank you-have tried swappin Relays-I checked them post by post and switch resistance -but could be somethin hinkey yet - thought to GUESS again (ha ha!) AND buy a new Relay-IF no change- will do what you advise unless you think it necessary to do before blow $$ on a fresh Relay (?)

[NW99XJ]

Troubleshooting a problem before you throw money at it is always good practice.... that being said... sometimes you have to buy a part to find out if the one in the rig is bad or not.

[4.3LXJ]

On that code, what the PCM senses is the flow of current through the coil in the relay. It does not sense the current going to the fan. I suspect you have a wiring issue or even a computer issue causing the code. Also, get that code erased at an Autozone store for free.