Greetings,
My wiper is possessed. The control does absolutely nothing. When the engine runs, the wiper turns on all by itself, and then stops straight up and down. Fiddling with the control does not make it stop or start.
Where should I start looking for this repair?
Previous owner cut the hose for the wash fluid. No clue why.

 

Maybe a bad switchpack, or connection issues at the motor end? Stopping straight up and down sounds like a power fault. If it's always stopping in the same spot, the system may be turning itself on and trying to "return" to home position, but the wiper could be centered incorrectly. If it sometimes stops in the correct home position, there is probably a bad connection somewhere. The wiper arm just clamps down, so it's easy to clamp it down at the wrong angle.

figure 14.1 here http://jagrepair.com/images/AutoRepa.../jagxj1998.pdf

 

There's a fault with the motor connection, water ingress. If you remove the centre piece of engine cover you can eyeball the power wires going into the motor itself.

A blast of WD40 could get it back in the room, but that's temporary.

They're bonded in with a silicone type glue, sometimes they can be repaired by removing the old sealant and cutting back oxidized wire ends then resealing with a high quality waterproof sealant (fish tank stuff is good).

 

Sooooo.... tested out the easy fix of repositioning the arm on the bolt.
Definitely not the problem hahaha
Moving on to the more complicated power issue. Thank you for your assistance!

 

I see the part you're showing me, but not understanding what I should be putting wd-40 on.

 

It seems like you're saying the problem is where those 4 wires are glued in on top there?

 

Yes, press down/wiggle the wiring to see if you can get a reaction. You can also check the wiring by the wiring diagrams located in the forum stickies.
Then check the switchpack at the steering column as their solder points can break and will need a resolder if it isn't the wiring going into the motor itself. It looks like your car has a replacement wiper motor fitted with the yellow writing on it, so a possible attempt at a fix? This could point to a fault at the other end (wiper stalk wiring). You'll need to search the forum for steering wheel removal to get at the part.
Hope this helps!

 

It is very possible they replaced that motor, I have no access to the prior owner's repairs, unfortunately.
I'll check the wiring and the steering column. I fiddled with this and loaded it with wd40 yesterday and could see the wiring under the goo and everything looked ok.. nothing broken, burnt, or corroded that I could spot. So, moving on!
You have been very helpful, thank you very much!

 

I had this happen once on a customers 98' XJ8. I'm pretty sure it turned out to be the BPM (Body Processor Midule). When I get a chance later today, I'll do some more digging in our wiring schematic.

 

Interesting... I can replace that easily. And for $100... is there a way to test it to see if that's the issue (barring actually buying the replacement and swapping it out to see if it stops lol)?

 

When you move the wiper switch, the input from the switch goes to the BPM. The BPM sends power to the wiper 'on/off' relay and the 'slow/fast' relay which are both located right next to the ABS module. I'd swap those relays first and see if they behave differently first before buying a BPM. I'd also check all your ground studs while your there.

 

I swapped the 2 relays and it did behave slightly differently, only it still seems to be confused as to where "home" is, because it still stops upright, or now at different spots, but still not where it should.

Also, when I turn the wiper off after any length of time it being on, it continues to run for about 15 seconds... is that normal?

 

The crazy thing even runs after the key has been removed! It won't start, but it will.finish it's 15 second cycle.

 

If the key was in your hand and its still running, it's a bad BPM.

 

Well thank God I don't have to take the steering column apart hahaha I'll happily pay $100 to not have to do that

 

Do you think the bad BPM would cause the temperature control sensor to fail?

 

For which system? Climate control or engine management?

 

Engine management, but never mind that question, I finally found a nifty booklet I downloaded that gives a run down of the bpm functions. Very interesting stuff. If the nearest jag dealer wasn't 2.5 hours away, I'd just check and see if they could reprogram it.

As far as the temp issue, I believe the engine coolant temp. Sensor is bad, the fans never kick on, and it seems the final possible reason after other troubleshooting. I wasn't sure what all the bpm did, so that's why I had asked that.

 

The very end of the link I posted gives a detailed rundown of what data is transferred around in the CAN and SCP networks, what modules sends/receives what data, and so on.

Your fans should also kick onto high when the aircon compressor is clutched on - if you have AC turned on and the fans never run, there could be something else going on aside from the temp sensor. Likely the motors are burned out or wiring or fan relays. The fan panel is easy to take out, and you can just feed the motors 12v and see if they run. If not, get working fans.

 

Thank you for that, I had no idea the fans worked in conjunction with the a/c. Just tested and the fans do come on when a/c is turned on. So that's good! Especially since I already ordered the sensor lol