Rear wiper won't shut off

Tiny
RUBANTIN
  • 1998 CHRYSLER TOWN AND COUNTRY
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 292,000 MILES

My rear wiper runs continually. Our liftgate has some body damage recently so I picked up a used voyager liftgate and guess what? The wiper still runs continually. What do I need to check? Also the dash lights for the wiper do not turn on. Could be related

Do you
have the same problem?
Yes
No
Sunday, February 27th, 2011 AT 6:31 PM

27 Replies

Tiny
CARADIODOC
  • EXPERT
  • 28,550 POSTS

There are two insanely unreliable computers involved in running the rear wiper. The HVAC controller with the control switches sends a coded signal to the Body Computer which has a very high failure rate. Start by replacing the Body Computer as a test. You might want to leave that to a professional as it is very difficult to remove. It's plugged in and bolted in front of the brake pedal.

Was this
answer
helpful?
Yes
No
Sunday, February 27th, 2011 AT 6:38 PM
Tiny
RUBANTIN
  • MEMBER

One more bit of info. The problem was intermittent at first. It would turn on by itself for periods of time. Longer and longer over weeks. Then it just stays on.

Was this
answer
helpful?
Yes
No
Sunday, February 27th, 2011 AT 7:11 PM
Tiny
RUBANTIN
  • MEMBER

Sorry gave you some bad initial info. The button lights do turn on and off but it has no effect on the wiper. Still does not shut off.

Was this
answer
helpful?
Yes
No
Sunday, February 27th, 2011 AT 9:19 PM
Tiny
CARADIODOC
  • EXPERT
  • 28,550 POSTS

I'd still suspect the Body Computer based it its history of causing problems with the front wipers. I'm sure the rear wiper circuitry will be the same.

Was this
answer
helpful?
Yes
No
Sunday, February 27th, 2011 AT 9:26 PM
Tiny
RUBANTIN
  • MEMBER

Ok. Just found a good used one on ebay for $59. Will give it a try.

Was this
answer
helpful?
Yes
No
Sunday, February 27th, 2011 AT 10:58 PM
Tiny
RUBANTIN
  • MEMBER

Any advice on making the replacement easier?

Was this
answer
helpful?
Yes
No
Sunday, February 27th, 2011 AT 10:59 PM
Tiny
CARADIODOC
  • EXPERT
  • 28,550 POSTS

There's three 5/16" or 10 mm bolts holding it in. I can't remember if there is also some type of latch, but the module will pull straight down. The hardest part is reaching up there to find those bolts. Use the replacement module to look at the locations of the bolt holes.

Was this
answer
helpful?
Yes
No
Monday, February 28th, 2011 AT 7:07 AM
Tiny
RUBANTIN
  • MEMBER

OK got a used BCM, put it in and the van starts and stalls. I saw where I might have to do a relearn or reprogram?

Was this
answer
helpful?
Yes
No
Sunday, March 13th, 2011 AT 9:21 PM
Tiny
CARADIODOC
  • EXPERT
  • 28,550 POSTS

Does your van have the factory-installed anti-theft system? I don't recall if this applies to the minivans but the Intrepids can use any Body Computer or Engine Computer from any car if it has factory anti-theft. If it does not have that system, you MUST install a used Engine or Body Computer from a car that also did not have anti-theft. If either computer has that upgrade programming it will teach it to the other one when the ignition switch is turned on. At that point both computers will require a "disarm" signal before they will work. That signal is never coming if the car doesn't have the anti-theft system. That upgrade programming can not be undone so both computers will have to be replaced at the same time before the engine will start. Again, I don't know if that applies to the minivans but it's a big source of frustration for Intrepid and older Neon owners. If you DO have the factory anti-theft system you might just have to relearn "minimum throttle" before the Engine Computer will know when it must be in control of idle speed. Before that is relearned you will not get the nice idle flare-up to 1500 rpm for a couple of seconds when you start the engine and it might only stay running if you hold the gas pedal down 1/4". That relearn procedure should only be necessary if the battery was disconnected or run dead. To relearn minimum throttle, drive at highway speed with the engine warmed up, then coast for at least seven seconds without touching the brake or gas pedals. The only minivan Body Computers I ever replaced were at the dealership with new computers. I didn't have to be concerned with the anti-theft systems because the module would work right out of the box on vans without it, and if it needed to be programmed for anti-theft, that happened automatically from the Engine Computer when the ignition switch was turned on for the first time.

Was this
answer
helpful?
Yes
No
Sunday, March 13th, 2011 AT 9:49 PM
Tiny
RUBANTIN
  • MEMBER

I just checked with the one I bought it from. My van has anti-theft and this one came from a van without it. So, I am sending it back for another one.

Thanks, will update when I get the right one.

Was this
answer
helpful?
Yes
No
Sunday, March 13th, 2011 AT 10:11 PM
Tiny
CARADIODOC
  • EXPERT
  • 28,550 POSTS

Nope, you have that backwards. No need to send it back. Since your van has anti-theft, that module will work just fine. Because you already installed it in your van, it has self-programmed itself to only work with vans with anti-theft. It learned that programming from your Engine Computer when you turned on the ignition switch. It won't work in any vans without anti-theft now.

Was this
answer
helpful?
Yes
No
Sunday, March 13th, 2011 AT 10:25 PM
Tiny
RUBANTIN
  • MEMBER

Then why is it stalling? It starts then stalls. In fact after doing that a few times then it would not even turn over. Like the starter had been disconnected.

Was this
answer
helpful?
Yes
No
Sunday, March 13th, 2011 AT 10:37 PM
Tiny
RUBANTIN
  • MEMBER

BTW. I reinstalled the old BCM and it runs fine.

Was this
answer
helpful?
Yes
No
Sunday, March 13th, 2011 AT 10:38 PM
Tiny
CARADIODOC
  • EXPERT
  • 28,550 POSTS

Oops. I have to modify my story. I only have a '97 service manual but I'm pretty sure the system is the same for '98. According to the manual, you must open the hood, then unlock the lift gate with the key. That will initialize the anti-theft system in the Body Computer and should allow the engine to start. Only the lights will flash. There won't be any horn when the anti-theft system is triggered until the engine has been started 20 times. I like this procedure better because it means you don't have to worry about where the used computer came from. Hope that works.

Was this
answer
helpful?
Yes
No
Sunday, March 13th, 2011 AT 10:38 PM
Tiny
RUBANTIN
  • MEMBER

Lol. How ironic. I just replaced the liftgate and do not have a key for it.

Was this
answer
helpful?
Yes
No
Sunday, March 13th, 2011 AT 10:54 PM
Tiny
CARADIODOC
  • EXPERT
  • 28,550 POSTS

I assume it's going to have to have the switch inside. If it doesn't, there might be a pair of wires in the harness that can be connected to a switch that can be operated manually.

Was this
answer
helpful?
Yes
No
Sunday, March 13th, 2011 AT 11:50 PM
Tiny
RUBANTIN
  • MEMBER

Will do thanks

Was this
answer
helpful?
Yes
No
Sunday, March 13th, 2011 AT 11:51 PM
Tiny
RUBANTIN
  • MEMBER

Uh oh. The new liftgate does not have the wire and switch going to the lock. I assume that this is part of the security system. Is there a set of connectors in the liftgate harness plug I can short to fool it?

Is the switch essential for the security system to function or does it only prevent detection of liftgate tampering?

Was this
answer
helpful?
Yes
No
Monday, March 21st, 2011 AT 8:09 PM
Tiny
CARADIODOC
  • EXPERT
  • 28,550 POSTS

Do I understand that you can turn the lift gate lock cylinder both ways for "unlock" and "lock"? On my old stuff I can only turn it clockwise to pop the latch. The wire you want is a 20 gauge white / red in the left connector. It needs to be momentarily grounded, but it's not that simple. There are two resistors inside the missing switch. The Body Computer sends a voltage out on that wire, and that voltage will change depending on the value of the resistor that is switched into the circuit. Typically they will send 12 volts out there, but it could also be 5 volts. It's irrelevant to the story but if we use 12 volts for the description, there are four possible conditions. Full 12 volts will be seen on that wire most of the time. If you ground it, there will be 0 volts. When you turn the switch to "lock", one resistor will be switched in and there may be 8 volts on that wire. In the "unlock" position a different resistor is switched in and there might be 4 volts seen on that wire. The 4 and 8 volts are interpreted by the Body Computer as the "arm" and "disarm" signals. There's a 99 percent chance grounding that wire would not cause any damage but most likely that will not initialize the anti-theft system either. You need to ground one end of a resistor, then momentarily touch that white / red wire to the other end of that resistor. The problem is they don't say what the values of the resistors are. There is a separate diagnostic manual for the anti-theft system that would have those values listed in the switch testing section. Is there any chance you still have the old lift gate? If you do you could read the resistor values with an ohm meter, then you would know the value of the resistor to use. From my limited experience with cruise control circuits, 560 ohms, 2200 ohms, (2.2k), 10,000 ohms, (10k), and 18k are typical values. That's how the computer can tell the difference between four different switches when only one wire goes to the switch assembly.

Was this
answer
helpful?
Yes
No
Monday, March 21st, 2011 AT 9:27 PM
Tiny
RUBANTIN
  • MEMBER

Ok. I do have the rotary switch on my old door. Can I wire it in even if it is just temporary?

Was this
answer
helpful?
Yes
No
Tuesday, March 22nd, 2011 AT 12:19 AM

Please login or register to post a reply.

Recommended Guides