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UltraMount pump motor

Discussion in 'Western Plows Discussion' started by MarkEagleUSA, Dec 30, 2012.

  1. MarkEagleUSA

    MarkEagleUSA Senior Member
    Messages: 321

    My pump motor seems to be drawing more and more power when in use. I recently replaced my alternator with a high-output unit and did the "big 3" battery wiring upgrade but the pump still really dims the lights. A recent fluid flush and fill had no positive impact either, so I'm guessing the motor is old and tired.

    Can the brushes be replaced on these units? If so, does anyone know a part number and/or source for them? Or, would I be better off just getting a new pump motor?
     
  2. 1olddogtwo

    1olddogtwo PlowSite Fanatic
    Messages: 11,523

    Replace it, the old one will probably fall apart when you take it off
     
  3. mishnick

    mishnick 2000 Club Member
    Messages: 2,243

    Bad brushes would result in a lower current draw, not higher. I would just replace the motor as a unit. If the brushes are toast then the commutator will need machining too. It's just not worth it.
     
  4. MarkEagleUSA

    MarkEagleUSA Senior Member
    Messages: 321

    What would cause higher current draw then?
     
  5. Chiputz

    Chiputz Senior Member
    Messages: 165

    Bad/ corroded connections will cause higher than normal amperage draws. If the bearings in the motor are worn, the armature in the motor can contact the fields in the motor and short out the motor. You're probably better off replacing the motor instead of rebuilding it.
     
  6. mishnick

    mishnick 2000 Club Member
    Messages: 2,243

    I agree with the bearings being seized drawing more power and also agree with the armature rubbing on the pole shoes shorting out and drawing more power but "bad corroded connections?" Corrosion causes resistance and increasing resistance causes a reduction in current flow in a non-inductive DC system. This is a common misconseption. Basic Ohm's law, increase the reisistance in a fixed DC voltage system and current drops. If this were true we would be in trouble because the infinat resistance across an open switch would cause an infinate increase in current flow. Increased resistance may cause an increase in heat at that point but not current flow.
     
  7. mishnick

    mishnick 2000 Club Member
    Messages: 2,243

    As mentioned above, bad bearings, or any other extra load on the motor, will prevent it from getting up to operating speed, which in turn will allow starting current (high draw) to continue flowing. Also any sort of short circuit in the motor like armature or field coil windings that are worn through, touching copper to copper allowing the current to bypass some of the windings. Another thing could be a stiff pump.

    Are you sure that the current is actually high? Dimming lights can be caused by high motor draw but is more often caused my a bad connection at the battery. Your plow motor draws more than the alternator puts out so if the battery is not well connected to the vehicle ground, and / or the main positive bus is not well connected to the positive post then the plow will pull the vehicle voltage down faster than the battery can fill it in.
     
  8. MarkEagleUSA

    MarkEagleUSA Senior Member
    Messages: 321

    I can't be sure it's a high current draw because I have no way to test it here at home, but that's my best guess.

    The battery connections were all taken off and cleaned when I put the new alternator in at the end of the summer. The alternator is a new 200-amp unit rated for 105-amps at idle RPM. In addition, I did the "big 3" upgrade. Used a 4 guage wire with a 250-amp fuse between the alternator output stud and battery positive. The grounds are 2 gauge from battery to engine, engine to frame, and engine to firewall ground lug.

    When I serviced the pump unit last month I removed and cleaned the two cable connections on the motor as well as cleaning the plow plugs at the grill. I used dialectric grease on all the connections too.

    With the new alternator, the voltmeter guage stays at 14 volts. The only time it drops is with the heater on high, headlights and brake lights on, and even at that it only drops to 12 volts. When I use the plow, the volts drop immediately down to 10 or so whether or not anything else is on. It will return to 14 volts within 2 or 3 seconds of releasing the plow control. I also had the 2-yr old battery tested when I did the alternator and it was ok.

    This is the 3rd winter I've had the plow. The first season we had a ton of snow and I used the plow a bunch. Last year I only plowed twice (small accumulations; not much time) so it wasn't really a problem, but both winters were with the old 100-amp factory alternator which is what prompted me to upgrade to the high-output model. The battery cabling was changed before last winter. Saturday we had 10" of snow and this voltage/current problem was as bad as it was 2 seasons ago which is why my first thought was a problem with the pump motor (high draw = electrical).

    I think I'll just order a new motor for it. If it doesn't rectify the problem I'll start looking at the pump. The plow is from around 2005 (the blade has the Western 50th Anniversary sticker on it) so I'm sure things are getting a little tired. I was just hoping to narrow the problem down so that the parts I decide to replace first solve the majority of the problem.
     
  9. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,966

    With the new alternator, the voltmeter guage stays at 14 volts. The only time it drops is with the heater on high, headlights and brake lights on, and even at that it only drops to 12 volts. When I use the plow, the volts drop immediately down to 10 or so whether or not anything else is on. It will return to 14 volts within 2 or 3 seconds of releasing the plow control. I also had the 2-yr old battery tested when I did the alternator and it was ok.

    somethings wrong if it drops to 12 with heater, lights, and bk lights. thats not alot of draw, if your saying your alt is rated at 105 at idle. id try that again with the factory alt installed.
     
  10. mishnick

    mishnick 2000 Club Member
    Messages: 2,243

    You sound like you are quite competent with the electrical stuff. You would be well served by investing in a clamp-on amp meter. But for now you could do some I R drop tests with your voltmeter. Take your volt meter and set it to a very low range like 2V or 12V and then connect it between battery + and the + terminal of the plow motor. Read the value while loading the plow motor. Do the same on the negative side between battery neg and the neg terminal on the motor. If you find a reading of more than 1/2 a volt then you know you have a bad connection in that curcuit. Think of it like standing on a garden hose. When water (current) is flowing if there is a restriction there will be a pressure drop between the two ends of the hose. If there is no restriction the pressure will be vertually the same.

    You say you put new output cables between the alternator output and battery positive right? And put a fuse in there? Why the fuse? Normally there is a fusable link but not a replaceable fuse. I would be checking for voltage drop across that fuse device.

    Dilectric grease.... I trust you didn't put this grease "in" the connection but just on it after it was connected. If you put it under the connection it will create resistance and voltage drop.

    Also consider the pullies / ratio running your alternator. The alternator may be designed to put out X amps at idle but it will also require a minimum RPM to get that. Your alt. pully may be too small for this depending on your belt setup and engine idle speed.
     
    Last edited: Jan 1, 2013
  11. MarkEagleUSA

    MarkEagleUSA Senior Member
    Messages: 321

    I went out and checked... apparently I was misreading the guage. At idle, the voltmeter reads 14.5 (max output of the alt). With everything on at idle, it drops to about 13-13.5. The weird thing is it doesn't drop until the I hit the brakes. That additional draw causes the drop. When using the plow, the drop is to between 10-12 volts.

    With the original alt the voltage would drop down between 11 and 12 (even after the "big 3" upgrade). That's what prompted me to go with the high-output unit.

    I keep meaning to buy one but never do.

    Everyone that sells high-output alternators recommends leaving the original charging wire (with the fusable link) in addition to adding the 4 guage wire with high-amp fuse. My alt is rated for 200 amps which is why I chose 250. The fuse and holder both have gold-plated contacts and I have triple-checked all the connections.

    Today I took all my battery and ground connections on both the truck and plow apart, cleaned them again, and reassembled everything just to be sure I hadn't missed something. There's still no noticeable improvement when operating the plow.

    The whole point of dielectric grease is that it doesn't impede current flow. I have always coated everything before assembly. It's the same principle as telling everyone to use the grease on the plow plugs.

    My alt is rated for 105-amps at 600 RPM and has a smaller pulley than the factory one.
     
  12. MarkEagleUSA

    MarkEagleUSA Senior Member
    Messages: 321

    I broke down and ordered a clamp-on AC/DC meter. It should be here Thursday so I'm going to wait to see what the amperage draw is before doing anything else.
     
  13. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,966

    Good deal. Test..don't guess. Everything you've done so far is for the better. So just to reask. What's the volts operating the plow..up and side side. And where are you testing it at
     
  14. MarkEagleUSA

    MarkEagleUSA Senior Member
    Messages: 321

    Watching the voltmeter in the dash, the plow brings it down to 10-12. Seems closer to 10 going up and left/right while pushing, closer to 12 left or right with blade up. I know this isn't close to scientific but the dimming of the lights is dramatic.
     
  15. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,966

    its a gm,,,,my old truck was a gmc and it had the gauge in the dash as yours does....it was off. i put in a digital gauge and that was the one i went by
    i can understand the dimming of the lights being worse going up,,,left and right your gunna see a little bit, but not close to the up dimming

    just a quick thought,,,,what kinda solenoid are you running for the plow??? and try the volt drop at that as well
     
  16. MarkEagleUSA

    MarkEagleUSA Senior Member
    Messages: 321

    It's the old-style Western solenoid. I do have a new new-style one in the garage.
     
  17. mishnick

    mishnick 2000 Club Member
    Messages: 2,243

    "The whole point of dielectric grease is that it doesn't impede current flow" Hmmm, not quite the way I would put it.... Try putting the two leads from your ohm meter in some dilectric grease. It's not a conductor ..... so putting it between your connections is not how it is meant to be used. Metal conductors should be clean when connected and then coated with dilectric compound afterward to seal them and prevent oxidization. Not that I expect this will be your problem because if this is the case it would cause a restriction to current flow, not overlaoding....
     
  18. MarkEagleUSA

    MarkEagleUSA Senior Member
    Messages: 321

    Finally had some time to test the current draw this morning. The motor is drawing between 100 and 125 amps at the initial press of the RAISE button and then settles at between 20 and 40 until full stroke is reached. With the blade raised, LEFT and RIGHT start between 80-100 amps and settle between 10-20 while the button is held. I tested at the motor and on the IN side of the solenoid and the readings are similar.

    I can't find any real reference to what these numbers should be but they don't seem to be abnormally high. What should my next step be?
     
  19. mishnick

    mishnick 2000 Club Member
    Messages: 2,243

    The current draw you describe is perfectly normal. High to overcome initial resistance and then drops to maintain motion. Not problem there. I would be going with voltage drop tests. Since the lights dimming seems to be the focus of your complaint I would begin testing there. Just measure the difference between the pos. terminal of the battery and the most pos. point of the headlights which would be the plug at the back of the bulb. The difference in voltage at those two points would idealy be 0 but if you get more than one volt you have a bad connection somewhere. The trick will be narrowing it down. Using the voltmeter again move one of the leads closer to the other along the path of power. At one point the voltage drop will dissapear and then you know you just past the bad connection.
     
  20. hoot

    hoot Senior Member
    from SE Pa.
    Messages: 156

    Might want to drop the reserviour and make sure the screen and return filters are clean and in place. Just a thought and easy to do.