'91 Windshield Washer pump does not stop - The Unofficial BMW M5 Messageboard (m5board.com)

CWY_M5 · 8th July 2008, 04:27

So I have been reading on the archive, but can't seem to find this same issue.

Also, I don't think '91 (09/90 build date) has intensive washer system, could be wrong.

In any case, my issue is - I can use the windshield washer spray no issue, how ever, when I use it, I can't "shut" off the water spray after I let go the lever. The ONLY way to stop it is by shutting the car down....

Any idea what could be causing this?? relay? which relay is it?

my AC also doesn't work, could it be related relays / fuses?

I checked all fuses, from the fuse compartment - anyone I have missed?

Thanks in advance.

Chino

E34_nut · 8th July 2008, 18:09

Hi Chino

The Washer Pump Relay is K5. I think this is the most likely problem. The relay contacts are pitted and stick once the relay has been energised. Try giving the relay a light tap with the handle of a soft screwdriver to see if it releases. If the tap works, the relay is almost certainly faulty.

The relay is contolled by the "General Module" located under the rear seat on the LH Side in the rear power distribution box.

When you turn on the washer, pin 6 on the General Module should go to 0V. When you turn the washers off, this pin show go to +5 or +12 Volts. If this pin stays at 0V after you turn the washer switch off, then the washer switch is probably faulty. I think this is unlikely.
The wire is coloured Brown & Violet.
You may be able to check this wire in connector X295 Pin 4. X295 is a BLACK 8 pin connector. It is located below the LH side of the dash, left of the steering column.
There are 2 BLACK 8 connectors in this area, so make sure you identify the Brown & Violet wire. X295 should be the lower of the 2 black connectors.

When the washer pump is running and switched on, Pin 10 on the Washer Pump Relay should be at 0V.
You can also check this at Pin 4 of Connector X13 or pin 22 of the General Module. X13 is a WHITE 21 pin connector, below the LH side of the dash below the drivers foot rest.
This pin should be at +12V when the Pump is NOT running.
If this pin is at 12V when you turn the ignition switch on, goes to 0V when you turn the washer switch on and stays at 0V when you turn the washer switch off, you should get professional help, because I suspect that will mean the "General Module" could be faulty.

Let me know how you go.

Chino, it's time for you to hunt down an ETM (Electronic Troubleshooting Manual) on the web.

It has all this info in it and will save you heaps of time. More than happy to help you interpret the contents if you find it a bit difficult.

Reg.

E34_nut · 8th July 2008, 18:37

Check fuses
F9 Compressor Clutch, Auxiliary Water Pump
F19 Blower Fan
F20 Heater Water Valves & Cabin Air Temp Sensor Fan & Climate Regulation Controlller
F25 Auxiliary Fan
F27 Climate Regulation Controlller
F29 Compressor Control Relay & Auxiliary Water Pump Relay & Auxiliary Fan Relay

Check Relays for contact corrosion
K4 Blower Relay
K8 Auxiliary Water Pump Relay
K19 Compressor Control Relay
K21 Auxiliary Fan Relay
K22 High Speed Fan Relay

Reg.
K86 (inside LH Kick Panel) Full Load Relay

CWY_M5 · 9th July 2008, 07:04

E34 Nut - THANK YOU.
I started looking into relays, and I fixed two things at once... well, sorta.

I don't know how you identify the K relays, all mu fuses were fine, I've checked. I still don't know how to check for relays, and your K4, K8, must designate a location which I still don't know what's what.. BUT, here's the good news.

1. I found out in the fuse box, there were two small relays on the left (in the bently 610-1, relay 5 and 6 were swapped. 5 was ac compressor control, 6 was washer pump relay. I m oved the relay from 6 to 5, and washer pump works fine now, and I now hear AC kicking in when I press the button.

Now, AC still doesn't cool, but that I believe is a different story.

You wouldn't happen to know what to look for next, would you? My mechanic converted the fitting to R134, and supposedly filled the system or checked with good pressure... now what?

but in any case, I'm ONE step closer in working out all the electrical bugs.. :-)

Archive reading time.

E34_nut · 9th July 2008, 17:21

Hi Chino.

Great news about the washer pump.

To identify the various relays, just use the descriptions in my post to find the equivalent positions in the Bentley diagram.
K4 in my post is the Blower Relay, the Blower Realy is in Position 4 in the Bentley Manual.

K21 (Normal Speed Relay) & K22 (High Speed Relay) are on page 610-3, Fig. 7 of the Bentley Manual.

Check page 640-8 "CAUTION" in the Bentley Manual.
I am sure that a mate of mine had a similar problem after changing from R-12 to R-134a in his late '90 M5. I think his diagnosis was a damaged expansion valve. It is possible that the R-134a corroded the expansion valve and it failed. I can't be absolutely sure about this because he is away at the moment.

IF I'M RIGHT, YOU SHOULD IMMEDIATELY GET TO AN AC SPECIALIST WHO KNOWS BMs AND GET IT CHECKED. I BELIEVE THIS CAN CAUSE PRETTY SERIOUS PROBLEMS IF THIS VALVE DOES NOT WORK PROPERLY.

Regards,

Reg.

unesential · 9th July 2008, 17:52

if compressor is short cycling then you have lost the charge. This is not unusual as many times a shop does not replace all hoses and other assorted items for a proper conversion. R 134 will escape escape from the system. Also if the system had a leak prior to conversion was the leak repaired?