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Bad Controller?

Discussion in 'Fisher Engineering Discussion' started by dirtymartini, Feb 9, 2014.

  1. dirtymartini

    dirtymartini Member
    Messages: 63

    Still working out bugs with my MM2 SD plow. I'm thinking maybe this is why the truck was traded in:dizzy:

    The newest problem is losing power to my joystick controller in the cab. Sometimes it happens when I hit a bump, sometimes the red power light on the joystick just starts flickering and I lose all control function.

    I have gone through and checked connections and all seems to be clean and tight. Looking at the schematic power for the controller comes from a switched accessory lead at the fuseblock, into isolation module plug 1 terminal C, goes back out on terminal D to the joystick plug terminal 1 under the dash. I can't see anything else (other than loose ground which I checked) that would cause the Joystick to lose 12V DC. I would like to check terminal one for 12V DC when it happens to try and isolate the Joystick controller but by the time I get my meter the power returns:gunsfiring:

    I have heard these controllers have been an issue...anyone else had these issues?
     
  2. chevyzrule810

    chevyzrule810 PlowSite.com Addict
    Messages: 1,238

    Can you swap controllers with someone and see if it is the controller?
     
  3. dirtymartini

    dirtymartini Member
    Messages: 63

    I wish I could...I don't know of anyone close by who has one. I wonder how sensitive the controller is to voltage drop? I noticed when raising the plow my voltmeter on the dash drops from 14+ down to around 10. I looked at the battery and it's only a 550 CCA.
     
  4. Antlerart06

    Antlerart06 PlowSite Veteran
    Messages: 3,437

    Not sure this will help on one trucks would same thing and the wire that runs to the fuse box wasn't making good connection all the time Everytime truck hit a pot hole the controller would shut off
     
  5. chevyzrule810

    chevyzrule810 PlowSite.com Addict
    Messages: 1,238

    What about bringing it to a dealer?
     
  6. dirtymartini

    dirtymartini Member
    Messages: 63

    I will check the fuse box wire again....It looked like a solid connection but my eyes aren't as good as they used to be!
     
  7. dirtymartini

    dirtymartini Member
    Messages: 63

    I'll do that when I run out of ideas or things to check. I am trying to eliminate the simple stuff first.
     
  8. Clint S

    Clint S Senior Member
    Messages: 280

    So I just had an issue with my stick losing power and the connection at the battery to the solenoid if bad will also kill power to the stick. Check those too as well as 12v at the small terminal on the solenoid.
     
  9. dirtymartini

    dirtymartini Member
    Messages: 63

    I figured for the $20 the solenoid cost I might as well go ahead and replace it.

    I thought that fixed the problem but today when I went out to plow I had problems again...losing power to the joystick controller. I checked all my connections and they looked good. While doing that I noticed I had no plow lights or truck lights (2004 Silverado) with the light switch in auto. I switched the light switch to manual on and power returned to the controller??? Since the lights in the truck work fine when the plow is not on could it be something in the Isolation Module???
     
  10. dirtymartini

    dirtymartini Member
    Messages: 63

    Update

    OK, here's something new...I discovered that since I have been running the light switch in my truck in the manual headlights on position I have had zero issues with the controller losing power. Any ideas?
     
  11. Clint S

    Clint S Senior Member
    Messages: 280

    What fuse is it connected to???? Is this a new problem or something you have had all along ?
     
  12. dirtymartini

    dirtymartini Member
    Messages: 63

    I bought the truck with the plow in August. This is the first winter I have plowed with it. Looking at the Schematic, there are two inline fuses that both are in the harness going to plug #2 on the Isolation module.

    The only time I have problems is when the headlight switch in the truck is in auto.
     
  13. Clint S

    Clint S Senior Member
    Messages: 280

    What fuse is the red wire connected to at the fuse block. On mine it was connected to a 10 amp fuse for trailer wiring, something went bad with that circuit and I switched it to the cruise control fuse (which my truck does not have). Can you change the switched power to another fuse. Do you hear a clicking noise when you lose power (Iso module)? When I lost power on mine I could hear that click. IIRC Fisher flowchart says if there is no power to pin and good ground at pin check Iso module. I have a EZV so I checked pin 8 for power and 9 for ground. Do not know what your pins are. Did you check the connection at the battery and at the solenoid as well as the small bolts at the solenoid. Power comes from there I think.

    ps I am no expert just trying to help, so my disclaimer is I think the info I am giving is good but......
     
  14. dirtymartini

    dirtymartini Member
    Messages: 63

    The red wire from the controller harness that goes to switched auxiliary 12v doesn't look like it is fused. It is hooked directly to a terminal at the fuse block.

    Since I started turning my truck headlight switch to the manual on position, the plow has not acted up once...and the last three days it has really gotten a workout here. All I can guess at this point is the problem is somewhere in the isolation module....just a guess!
     
  15. Clint S

    Clint S Senior Member
    Messages: 280

    Yes it is tapped into a fuse at the fuse block. What circuit it is tapped into. Usually a 10 amp fuse via a fuse tap.

    Here is how I THINK power to the plow works.

    Power from the battery goes into the iso via the solenoid wire. The switched power wire activates the iso and allows the iso to power up the system. If either switched power OR power to the iso is compromised the plow will not power up. IIRC the Fisher troubleshooting chart says if no power to the pin in the stick hook up run Iso Module diagnostics. So it could be in the switched wire and to the solenoid wire, but none at the controller. Could also be the controller. Smarter minds than mine know how the iso module works to provide power
     
    Last edited: Feb 16, 2014