Manager Forum

The wipers fail to operate, so here's what we did:

1. Tested the motor - it works fine.
2. Tested the switch - it works fine.
3. Tested the lines for power from the motor to the relays & from the relays, through the
firewall, and inside the vehicle to the switch - looks good.

Then we were stumped!

I read that it may be the BCM, but before I ordered one in, I asked my tech to verify power to and through that unit. He claims that our scanner can't communicate with the BCM, and that there is no power coming out.

If that is so - wouldn't there be more things not working besides the wipers?

Any advice before we try to get a replacement BCM for our customer?

DARRAH

they have an issue loosing ground. run a new ground wire from the BODY of the motor to ground. don't be fooled by the test light test when testing for a ground . the light will pull a .003 load to light where the motor can take 20 amps to work. woah, talk about repetitive.............

We're checking on the ground issue - but I have another related question:
Does anyone REALLY know whether the BCM needs to be reprogrammed? I'm being told by some that if I replace it for my customer, I HAVE to get one that has the same number on it, some are saying that even then, it will have to be re-flashed, and others are saying that the number doesn't matter BECAUSE it needs to be re-flashed anyway. The dealer says to forget all that, and just replace it with a new one for about $800....plus the reprogramming fee?

DARRAH

I always go o.e. with the reprogram

HOW WOULD YOU WIRE A TOGGLE SWITCH IN TO RUN WIPERS DIRECTLY W A DOUBLE TROW SWITCH PLEASE EXPLAIN PERCISELY

DARRAH wrote:HOW WOULD YOU WIRE A TOGGLE SWITCH IN TO RUN WIPERS DIRECTLY W A DOUBLE TROW SWITCH PLEASE EXPLAIN PERCISELY

Maybe its just me but I wouldnt.

DARRAH wrote:HOW WOULD YOU WIRE A TOGGLE SWITCH IN TO RUN WIPERS DIRECTLY W A DOUBLE TROW SWITCH PLEASE EXPLAIN PERCISELY

This would be risky move in todays world, not to mention it is not a good way to fix things. That said, if the money issue will completely stop the repair from happening, you could run from a fused power source and wire up the motor like you did to test it and install a switch in the circuit.

The toggle switch was the customer's inquiry...we told him the same thing in regards to it being a problematic solution at best.

We found a salvage BCM that came from the identical year/model vehicle with the identical options...same number on the casing for the unit, even.

Plugged it in, and still no wipers.

I'm starting to think we need a fresh set of eyes on it - testing all the lines again, ...not sure what else it could be!

Panicked,

DARRAH

The BCMs are so problematic that it would not be unreasonable to say the replacement is dfeffective. To check for sure, unplug wiper switch and check the DkGrn/Yel or DkGrn/Red (could be either color) for 5v with ign on and wiper switch unpluged. If not 5v then make sure wire is intact and not shorted to the BCM. This is the common problem on these vans. If no volts and wire good, BCM is bad. Hope this helps, I know what it is like to replace a part and have the dsame problem, it can really make you doubt your diag abilities. Hang in there, you'll get er done!!

i know you say that everything checks out and it still doesn't work. well something must be out of whack. the flow of diagnostics is fairly easy. there are two relays involved. wiper on relay next to fuses 23-24, power high low relay next to fuses 25-26. see if they are clicking on when commanded. if not you have a bad switch or bcm. bcm's will and can cause a big array of issues. on occasion techs will over think the issue. just follow the simple diagnostic flow and go from there. yes to the re-burn question. another thing is that a good scanner will get into the bcm function and you can see if the module is commanding wiper operation. used bcm's may or may not function. personally i won't use used p or bcm's. it always adds to the chase. you want to replace a questionable part with a good one. although i've had the pleasure of replacing modules with oem remans and have them be defective.........................

Well....here's the confirmed fix:

Replaced the BCM (Wasn't communicating with scanner)
Replaced the REMAN Wiper Motor for faulty park switch
Replaced the switch in the column due to component failure.

After adjusting the stroke, the wipers work fine...customer was even pleased as he was reminded that the power locks are supposed to engage at 15 mph...a sound he hadn't heard for more than a year...

Thanks for all your help!

DARRAH

Thanks for posting the fix, I am glad you got this one fixed, now you should have a customer for life. Give yourself the Hero cookie for the day.

Can't be eating Hero Cookies...all too often, I end up eating Crow, and it fills me up...

Ok - This one has me stumped (again). I've attached this to the old post, because it's the same vehicle...

Customer returned to state that periodically, when they go out into their driveway and open the driver's door...the wipers come on.
If I didn't see it myself, I would have thought the customer was nuts. It's only intermittantly...but sure enough, we recreated the symptom several times.

Any idea how this might happen. I mean, the ignition is off, for Pete's sake!

Anymore thoughts?

btw - They have worked fine since our "fix" the last time it was in, until the last few days.

Thanks,
DARRAH

My dodge pick up will honk the horn at times when I open the door. No alarm or keyless entry on this vehicle. I live with it but can't splain it Lucy.

BCM?

There's a TSB for an updated multifunction switch on these for erratic wiper operation when you don't even have the wipers on. I'm guessing some stray voltage is tricking the bcm into thinking there was a wiper on command.

08-31-98a

a suggestion here, keep customer in the loop as far as all the posted quirks with these mini vans. they're a wild little group here. they should be a cast member of the "ghost whisperer". i agree with ric as far as the switch goes. even though the key is off when you open the door the interior light will come on and if the switch is faulty it will allow an impulse to pass through to the bcm and wham, wipers come on.