wiper electrical problem

[ray and pat]

I,m a bit new to this amazing forum and community of knowledge and I,ve done a search of all related posts but still havent been able to fix my problem .I have a 1990 crewcab diesel 1.9 tdi m(done by the previous owner) and its a great drive.

I have already checked and cleaned the earth connections under the dash and steering wheel bottom, and the fuses and the connections to the wiper switch, and replaced the relay number 19 to no avail , and all seem to be ok. But the wipers still wont self park - I have to turn them off with the wiper switch when they reach their bottom position. also the interval wipe just does one interval wipe and then reverts to continuous wiping.

Anyone got any ideas what else I can check please. I,m hoping it isnt the wiper motor but running out of things to check.

[bigherb]

Have you checked fuse 17 has power to it.

[ray and pat]

yes I checked both fuse 11 and fuse 17, both have power and are ok. Thats why I seem to be running out of things to check

[bigherb]

Have you got power at the wiper motor with the ignition switched on (Black/Grey wire)

[ray and pat]

yes,checked with voltmeter and definetely got power on black/grey wire.I thought it was going to be an earth problem but checked just about everything and still cant find it

[Oldiebut goodie]

I once had the same non-parking on an old Volvo - there was a diode that had blown inside the wiper motor casing.(not much help I know, as you would still need to get the motor out)

[Grun]

ray and pat,
Before taking the dash out to get at the wiper motor, it would be worth checking that the limit switch is working.

From Haynes wiring diagram........ with ignition on, if you select the wiper switch to the stop position with the blades around mid travel, then there should be battery voltage at connection 53a on the wiper switch. (Green wire)

Circuit is from fuse 17 throught the (closed) limit switch contacts.
If no volts, either limit switch or wiring to/from are defective.

If you have +ve at 53a it should appear at 53b (Green/Grey wire) on wiper switch (with switch in off position), if not, wiper switch contacts/connections suspect.

Never had the wiper motor out so don't know if limit switch is adjustable / repairable.
Intermittant wiper operation is dependant on limit switch operation.

Mike

[ray and pat]

thanks for that. checked again with voltmeter with wipers in mid position and wiper switch off. nothing on the green wire either at the switch end or back of relay/fuse box connection, or at wiper motor connection. But I discovered that that green wire becomes live when the switch is in the interval wipe position only . now I,m even more baffled.
I also have green/yellow wire live with wipers in fast wipe position.
green/black live wth normal wipe and interval wipe.
and of course gray/black live with ignition on.This is the same even if I disconnect the connector from the wiper motor. I,m beginning to wonder if the wiper relay I changed was faulty. I shall go to try to get another one tomorrow and try that just in case.

[bigherb]

If you want to eliminate the relay, remove the relay and bridge acrross with a piece of wire where pins 53S and 53M fit in the relay holder.

[ray and pat]

just a quick update. many thanks for all advice. after eliminating everything else it turned out to be the wiper motor (limiter switch) so I ordered a new wiper motor off ebay and fitted it last weekend- must admit to cheating a bit because didnt fancy taking whole dasboard out, and as I have one of those dash tidys I cut a hole under it just big enough to get better acces to wiper motor. still a bit cramped for space but managed it and now all working fine, and hole in dashboard is completely covered over by dash tidy!