Wiper issue

[PatrickMTL]

Alright, this one is a little weird, so here it is in point form:

-Wipers run any time the ignition is on, and the relay makes a screeching sound non-stop.

-Installed new relay courteousy of Zen Wrench, problem solved, wipers perform perfectly.

-Relocated battery to trunk using the TEP kit.

-Wipers turn on, but continue to run after switch is turned off. Turn off ignition, wipers stop. Turn on ignition, wipers park themselves.

-Switch functionality has been verified with a multimeter.

-Motor has been opened, contacts(3) are intact, cleaned and re-greased the mechanism.

-I'm stumped. Please help me regain sanity.

[Guest Anonymous]

Oh Boy You just found one of the biggest stumpifyers in o2 wrenchin, I can tell u the problem but it took me a week to figure it our, maybe you have a bigger German part of your brain? Inside the motor their are contacts, these get gummed and fuddled up, dis motor and start cleanin, dont try to figure out thinkin or it will take a month, if nothin is found to be broke they will work again, just dont give up and repeat process til u hit it right

[PatrickMTL]

I edited my post-I did open the motor and inspect the contacts. The odd thing is that the motor parks itself, but only if current is interrupted. I am baffled.

[PatrickMTL]

I have since posting this message disconnected the running motor, with the switch in the "off" position, ignition "on", from the plug. It stops, duh, but continues running when I plug it back in. If I turn the ignition off then on, it parks itself and stops. Could the relay be faulty and locking itself in the "on" position until the ignition current to the relay is disrupted? Hey Mike in Beavercreek, what's your professional opinion?

[c.d.iesel]

1) the TEP batt relocate had nothing to do with the wiper ailment

2) replace the relay with one from BMW /Hella

[wegweiser]

Hey CD! I sold him that used relay last month! You're making me look bad! *jerk!*

Seriously Patrick - if it's junk, I'll take care of ya'. You know it.

[PatrickMTL]

Hey CD! I sold him that used relay last month! You're making me look bad! *jerk!*

Seriously Patrick - if it's junk, I'll take care of ya'. You know it.

NO WORRIES Paul, I'll figure it out. It is perplexing because I'm pretty confident the relay is good. I'll get a chance to look at it later tonight.

[Guest Anonymous]

Dimes to doughnuts its in the motor, identical ailment had me huntin for a week. As I recall the roundie wiper motor always had juice in it, the contacts in motor actualy stop the current to run wiper motor. Good luck and want to hear the outcome, havin flashbacks.............

Dave Miller

[PatrickMTL]

I've already had the wiper motor open, all the contacts are fine. Plus, when I interrupt the signal either by unplugging the relay, or the ignition, the motor parks itself and stops. Since posting I've pulled the cover off of the relay to watch it in operation; the relay seems to stay in the closed position until I either turn the ignition off or unplug the relay. My judgement is the relay sticking closed. Any opposition or suggestions on how I can test the relays operation? I'll work on getting a new relay tomorrow and post my findings.

[bnam]

There are some relays that are closed when off vs open when off. Perhaps you have the wrong type

[Kpeters]

I'm having the exact same problem with the E21 with the previous relay the wipers would only work on low speed or high if placed on interval the wipers would stop. (Usually under a pretty bad storm).

Replaced the relay with a "good" used one and it started working good then I noticed it the intervals got faster and suddenly it started skipping interval and went to low. They won't shut down either until I stop the car and then put ignition on and they will park.

My money is on the relay but please do let me know what it is in your car maybe it'll shed some light on my problem too!

BTW if you end up needing a new relay or motor let me know I can fix you up.

[PatrickMTL]

Tapping the relay with the wipers running, but the switch in the off position parks and stops the wipers. It's the relay. Any objections to this diagnosis?

[TobyB]

Could the relay be faulty and locking itself in the "on" position until the ignition current to the relay is disrupted?

yeah, it's latching somehow. Here's where your brain might start hurting-

if the motor's backfeeding current into the relay coil, it'll hold the relay on.

The park 'window' on the wiper motor is quite short- and the contact to 'park' actually grounds the motor rather than just unhooking it.

If it's NOT grounding the motor, the motor coasts right through the

'park' window and keeps going.

Just think 'back EMF' and you'll be fine!

(sorry...)

heh

hth

t

[PatrickMTL]

Could the relay be faulty and locking itself in the "on" position until the ignition current to the relay is disrupted?

yeah, it's latching somehow. Here's where your brain might start hurting-

if the motor's backfeeding current into the relay coil, it'll hold the relay on.

The park 'window' on the wiper motor is quite short- and the contact to 'park' actually grounds the motor rather than just unhooking it.

If it's NOT grounding the motor, the motor coasts right through the

'park' window and keeps going.

Just think 'back EMF' and you'll be fine!

(sorry...)

heh

hth

t

My brain is already hurting...

When I think EMF, all I come up with is "Unbelievable", it's a catchy tune, but that 90's jam hasn't helped me understand what you're hinting at. ?

If I were to tell you that unplugging the motor, while it's running with the switch in the off position, then plugging it back in and that the motor continues to run, does that mean anything to you?

[dbmw2002]

Welkcome to Berlin, it only gets better, the motor contacts are fine, auto stop contacts need lovin, dont give up.