Hi everybody Bill here have an electrical problem that is really driving me crazy!! Ok I have a 99 cherokee sport picked it up last week ran well looks good but gauges did not work , no interior lights and no dash gauges no power locks and cel light on of course .. By some miracle I was able to find a broken wire by the blower motor in the engine compartment in the smaller harness that looks like it might going through the firewall and to the interior fuse box, it was a pink wire, I repaired it ,soldered and shrink wrapped that gave me back the dash gauges and the interior lights. I then went and checked all grounds found the one by the dipstick broken right at the eyelet I cut it back and repaired that , next the power locks it was the switch on the pass. side was disconnected because when plugged in it would just trigger the locks on its own., took switch apart cleaned it with contact cleaner and emery cloth works perfect.. Now with a cold engine I insert key in ign and turn to the run position right before starter engages and you can hear the a/c clutch jumping in and out switch is off and the fan starts to run?? I have checked every fuse and relay at least 5 times both with a volt meter and removed and visually inspected inside fuse box and pdc box outside on fender wall.. and they are all good Oh I can get the jeep started but not without pressing the fuel pedal..and it runs well once started, but no fan even after 20 min and reaches temp to turn fan on . I have also unplugged every connection ,cleaned it ,greased it with dialectric grease and replugged it.. I also took the tcm and pcm out of my son`s jeep also a 99 and still same thing!! I searched the forum and can not find any any similar problems?? Really need help with this one we have seven of these cherokes and while I am pretty familiar with them this one has me stumped.. Hate to throw in the towel but don`t know how much more I can do??(I am old lol) I also changed the ign switch.. My small actron scanner is not allowing me to read codes is keeps saying com failure the one time i did get it to read it was p1694 communication malfunction.. Sorry to run on just trying to give as much information as possiable.. Oh Dinner for the guy/gal who figures it out lol Thanks Bill

 

Oh boy I was really hoping somebody could figure it out I forgot to mention I did change the ign switch but I am pretty sure they can only go in one way?? Nobody want`s a free dinner? lol!! Thanks in advance Bill

 

Okay......... one at a time here. coolant temp sensor/switch may be bad? Start problem could be a bad wire or relay not sending signal unless under load? Bad ground(s)?

 

Thanks for the reply I checked every ground the only one that had a break was by the dipstick I repaired it and took every one off fenders and block by coil and rear of engine from headbolt to truck cleaned and checked them all seemed good.. Sensor have to check I did switch it out with a know working one same thing?/. Bill

 

See here:
https://www.cherokeeforum.com/f2/rep...94-code-97095/

and here:
https://www.cherokeeforum.com/f2/nee...gnosing-37389/

Agreed on checking the temp sensor. The secondary fan won't come on until you hit 212 or somewhere in that neighborhood, how hot is the coolant getting?

Is your defroster or AC on by chance? If so, try setting it to off and see if the clutch and fan still cycle.

 

Thanks Radi, no the defroster is not on and the a/c is off also, I can only get the fan to operate by jumping the switch on top of the dryer?? or if you turn ign to the run position before the start or crank position., then it works fine I have checked the fan it spin`s freely .The temp gauge is sitting directly at 210 right at the line.. I felt the fan should go on as it does in the other jeeps ?? , and can not seem to get it to go higher ?? I went on your recomended sights and I am going to have to try and see if I can figure out how to check the wires from the pcm to the tcm? for communication , I am really just a hobbist semi retired guy doing this for my son , daughter, nieces and nephews, , so not really versed on it (wiring) Back to the drawing board !! Have to try to teach myself how to trace wiring other than a visual inspection..

 

check your battery I had a bad one and caused all kind of problems.... Mine had a bad ground inside the battery..... also check the fuse box a little bit of a pain to get out but check it out by take the back off and see if any water/moister got in it

 

Not sure about where you live but if someone treated the wiring like a tractor and not a car, you may have some splicing to undo or reroute.

 

Thanks Guy`s I checked the battery it is good, the fuse box is a good idea, harness looks pretty virgin except for that one broken wire does not appear that anybody ever tampered with it?? ,never did remove as fuse box but first time for everything I guess .,Oh I live in Long Island New York., Sort of taking a break another nephew just returned from afganastan, (spell check lol) thank God although combat wounded ,purple heart bunch of other medals he is good so we have been partying and hopefully going to take him to Atlantic city . My other nephew his brother returned from three tours in Iraq fortunetly also in good shape now in the nypd academy also had big party`s for him , so what you do for one you must do for the other lol ,( I built jeeps for each of them also) I just want to party , celebrate, dinners etc... also and of course show my respect and happy they are home safe.. I am very proud of their sacrifices and them also in keeping our great country safe and protected !! .. So as much as I would love to solve jeep problems this is more important to me .. I will get back to it next week.. but thanks for your reply`s will check back Thanks again, Bill or seven..

 

Welcome home.

I did my time over there, USN, Desert storm and desert shield 92 to 96.

 

Tell them for me: Welcome Home, and Thank You For Your Service.

Ken, Vietnam, Class of '67.

 

Hi guys Bill here again back from our little get away ., First I would like to thank the fellow vets who sent good wishes to my nephews , Thank you for your service also... and your thoughts are appreciated and forwarded .. we had a lot of fun and hopefully they can adjust to civilian life .. (good Luck).. Anyway was back on the jeep a friend came over with his snap on scanner and a good jeep mechanic unfortunetly he could not make heads or tails of it either?? We went over the entire harness again checked every connection and ground all was good?? checked the white /bk stripe wire and the violet /brown wire between the pcm and tcm with his fluke meter and got a 04 ohms between the two, which according to code p 1694 that means no break in wire and was finally able to get it to communicate no codes found but relays still clicking and fan going on with key in run position but not running.. We did find that the alternator is putting out high volts at idle it is putting out +16 volts?? very high and then sometimes it will drop to nothing checked with two volt meters and dash gauge pretty much all the same.. My buddies theory is that the alternator is bad and is putting out way to much voltage and possiaebly fried the pcm??.. He is a good mechanic does it full time but is not 100% sure I figured I would throw it out their and see if anybody else can shed some light before I start throwing more money in it ?? We did disconnect the power and smaller plug to alternator with the same results.., Any advice is greatly appreciated and Thanks again to all the vets for your service..

 

The voltage regulator is in the PCM. I'd start by bench testing the alternator and getting that squared away. If the problem persists after that you might have to look at the PCM.

 

X2, also the high voltage can cook off the battery so you may want to have it once overed as well.

 

Thanks for your reply I went out and picked up an alternator same thing so pretty sure it is not that I guess it is in the pcm?? the voltage is very erractic and runs high almost 17 volts on idle , when you load it up (lights, heater, ) it will really drop enough so the check gauges light will come on..and reads about 9 I hope I did not burn up this one?? any more thoughts love to hear them Thanks again Bill