Results 1 to 17 of 17

Thread: washer pump electrical issue

  1. #1
    Join Date
    Oct 2014
    Location
    San diego
    Posts
    29
    My Cars
    1995 325i

    washer pump electrical issue

    So I replaced my washer pump. Using a tester light the connector to the pump shows current on both the negative and positive side. This is with the washer switch activated. Is this normal? I am not an electrical wizard but isn't the negative side supposed to not light up with the tester. I am thinking an exposed wire but peeling the tape back all the way to the corner of the engine by the headlamp I see no damaged wiring. Fuses are good. Is there another relay or fuse besides the engine bay fuse box? 1995 bmw 325i.

  2. #2
    Join Date
    Jun 2010
    Location
    NY
    Posts
    9,079
    My Cars
    1997 328i
    The same amount of current that flows through the positive will flow through the negative when the pump is activated.
    Attn. NEWBIES: Use the search feature, 98% has already been discussed.
    Click the search button, select "search single content type", select the "e36 sub forum" specifically, try the "search titles" then try the "search entire posts".

  3. #3
    Join Date
    Jun 2010
    Location
    NY
    Posts
    9,079
    My Cars
    1997 328i
    The squirters are working? There are tons of vids on YouTube that can teach all the basics, voltage, current, resistance etc.
    Attn. NEWBIES: Use the search feature, 98% has already been discussed.
    Click the search button, select "search single content type", select the "e36 sub forum" specifically, try the "search titles" then try the "search entire posts".

  4. #4
    Join Date
    Oct 2014
    Location
    San diego
    Posts
    29
    My Cars
    1995 325i
    The pump is new. The squirters are clear. The wipers work. Fuses are good. No sound from the pump when the the switch is activated.
    Coud it be the switch itself even though the wipers work?

  5. #5
    Join Date
    Oct 2014
    Location
    San diego
    Posts
    29
    My Cars
    1995 325i
    Also no tester light activation on negative side.

  6. #6
    Join Date
    Oct 2020
    Location
    Manitoba, Canada
    Posts
    742
    My Cars
    e36
    No idea what you're doing, but what you're supposed to do is: take off electrical connector of the pump, put your test light on one wire connector, one should be negative and therefore not light up, because no voltage is there, then there's the positive one, and that one shouldn't light up without the switch activated, but should with the switch activated. If it does, you know switch and fuses are good, if it doesn't, you know something is wrong with wiring, fuses or switch. Then you should put 12V directly from a battery to the pump and see if it moves, to be sure it's not faulty out of the box. My tool tells me if negative or ground is present, if yours doesn't then you technically can't diagnose a bad wire with this method, for that you'd need an Ohm-Meter to check if the connection from connector to ground is good.

    You could also take a 12V bulb and connect it to the connector and see if it lights up when activating the switch.

    That should give you an idea what's wrong.
    Last edited by importbanana; 12-09-2020 at 11:18 PM.

  7. #7
    Join Date
    Oct 2014
    Location
    San diego
    Posts
    29
    My Cars
    1995 325i
    Tested with car on, switch activated, battery with 12 volts, pump is new and tested and fuses are good.
    Voltmeter shows 1.2 volts.
    Besides the fuses is there a relay involved?

  8. #8
    Join Date
    Oct 2020
    Location
    Manitoba, Canada
    Posts
    742
    My Cars
    e36
    read the electrical schematics to answer that

    What do you mean 1.2V? Is that with the connector on the pump? That's not a useful measurement. I ask because you mention new pump, which doesn't have anything to do with the Voltage measurement for now. In case you did you measured the voltage drop the pump caused. If it was the voltage coming to the connector with the connector off the pump you should look at the electrical schematics to see what to check next.
    Last edited by importbanana; 12-13-2020 at 02:38 AM.

  9. #9
    Join Date
    Oct 2014
    Location
    San diego
    Posts
    29
    My Cars
    1995 325i
    bmw wire.jpgbmw wire 2.jpg Wired at the harness near the fuse box with the switch activated. Same reading at the connector.

  10. #10
    Join Date
    Oct 2020
    Location
    Manitoba, Canada
    Posts
    742
    My Cars
    e36
    it's bad to damage your harness like that.

    i think you're doing the wrong measurements, therefore the values you've measured won't bring you any further

  11. #11
    Join Date
    Oct 2014
    Location
    San diego
    Posts
    29
    My Cars
    1995 325i
    I was trying to determine if the wiring was bad. I assumed the problem is closer to the fuse box or maybe even the switch even though the wipers work. I am baffled and don't know what to do next. Is there a ground wire I cannot find that needs looking at?

  12. #12
    Join Date
    Jul 2010
    Location
    Murrieta, CA
    Posts
    9,528
    My Cars
    '94 325iC, '08 328i, E93
    Unplug the pump.

    Connect your red meter lead to the positive wire (not brown) and the black lead to to a bolt on the engine or chassis, and try the sprayer switch. If volts, the circuit is good and the pump is bad. If no volts, the circuit is bad, likely the switch itself.

    The wire that isn't the power wire is ground, and is brown. This wire should be a direct short to ground without regard to the switch. It's not out of the question that a brand new motor from the part store is defective, and odds suggest that it's not new at all, it's rebuilt (which increases the odds that it's defective).

  13. #13
    Join Date
    Oct 2014
    Location
    San diego
    Posts
    29
    My Cars
    1995 325i
    bmw ground.jpgOkay! I have voltage through to the connector. Plug it in and no pump action. Connecting the pump to the battery and the pump works. What next?

  14. #14
    Join Date
    Jul 2010
    Location
    Murrieta, CA
    Posts
    9,528
    My Cars
    '94 325iC, '08 328i, E93
    The washer motor circuit includes the switch, the washer pump and the washer module.

    It appears that the pump works via a switched ground, not a constant ground. In a typical automotive circuit, loads are grounded all of the time, and the power is switched to turn the load on or off. Using this typical circuit construction, we (I) gave incomplete information earlier. When you stated that you hardwired the pump directly to the battery and got it to work, I pulled out the schematic to confirm what you did and what I told you to do. It seems I made an error that needs to be clarified. Let's begin anew...

    The motor (pump) has 12v on it on the VIO/BLK wire that comes from F44, 15A that also goes to the module. This line comes from the fuse, and its hot in ON, RUN, and START. The line splits and goes to the pump and to the washer module, Pin 8. This means that the power to the pump is always hot, and a ground is needed to make it turn on.

    The ground path goes from the chassis, to the wiper switch then to the washer module, where the washer module uses a combination of wires to produce the wiper speeds. We are going to ignore the wiper motor and focus on the washer pump. Generally speaking, BRN wires are tied directly to the chassis, and BRN wires with a stripe, BRN/VIO, BRN/YEL, and so on, are grounds that are switched by a module somewhere.

    There is a constant ground (BRN) wire on Pin 1 of the wiper switch. The wiper switch then passes a ground to the washer module that in turn provides a ground to the washer pump. The wiper switch has a BRN wire on Pin 1 that is grounded, when the washer is selected by the switch, the ground from Pin 1 passes to Pin 5 (BRN/VIO) that goes to the washer module Pin 11, and out to the washer pump at Pin 10, also BRN/VIO that goes to the washer pump, Pin 2.

    The washer module is also called the Wiper/Washer Module. You have either a failed module or a bad washer switch. The failure in the module will be a transistor or solder joint, that sort of thing, and the wiper/washer switch will have a burnt or dirty contact.

    To test the switch, unplug it and connect your meter to Pins 1 & 5 and set the scale to Ohms. Operate the switch to make the pump turn on, the meter should go from open to short (infinity to zero or some very small number like that). Pins 1 & 5 of the wiper switch will both be populated by BRN/VIO wires on the switch side of the connector.

    - - - Updated - - -

    Also, you are operating with less than 11 volts, this means you might need jumper cables or a battery charger to start your car.

  15. #15
    Join Date
    Oct 2014
    Location
    San diego
    Posts
    29
    My Cars
    1995 325i
    Whew!
    OK, so when we are talking about the switch we're talking about the Wiper washer switch on the Steering wheel?
    Where is the wiper washer module? Will keep an eye on it and recharge later.
    The battery on the car at off shows 12 V. It did struggle to start.

  16. #16
    Join Date
    Jul 2010
    Location
    Murrieta, CA
    Posts
    9,528
    My Cars
    '94 325iC, '08 328i, E93
    Quote Originally Posted by Abelsaiz View Post
    Whew!
    OK, so when we are talking about the switch we're talking about the Wiper washer switch on the Steering wheel?
    Where is the wiper washer module? Will keep an eye on it and recharge later.
    The battery on the car at off shows 12 V. It did struggle to start.


    Yes, the stalk on the steering column.
    it looks like the wiper/washer module is located on the firewall behind the glove compartment.

  17. #17
    Join Date
    Oct 2014
    Location
    San diego
    Posts
    29
    My Cars
    1995 325i
    Thanks. Will check tomorrow.

Similar Threads

  1. Fuel pump electrical issues
    By Brob in forum 1975 - 1983 (E21)
    Replies: 9
    Last Post: 11-16-2022, 03:40 AM
  2. Aux. Coolant Pump Electrical Issues
    By anavabi in forum 1999+ X5, X6 (E53, E70, E71, F15, F16, G05, G06)
    Replies: 0
    Last Post: 01-19-2020, 03:08 AM
  3. Secondary Air Pump Electrical issue
    By Louisrocco in forum 1999 - 2006 (E46)
    Replies: 2
    Last Post: 08-28-2016, 09:35 AM
  4. Windshield Washer Pump / CPO issue
    By SCsailor in forum 2004-2010 (E60,E61)
    Replies: 2
    Last Post: 12-04-2013, 12:48 PM
  5. washer pump/jet issue
    By n2w in forum 1999 - 2006 (E46)
    Replies: 7
    Last Post: 06-11-2013, 07:07 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •