# Intermittant power problem Fisher Plow



## RoCo (Jan 16, 2011)

I have a 2010 GMC 3/4 WT with new Fisher 8'HD MMII plow. When I first start plowing everything functions properly. Then all of a sudden (usually within a couple of minutes) I loose power to everything. No plow functions, not light on joystick control, no DT running lights...NOTHING!!! If I shut down all accessories, heater, radio etc and wait 5 to 10 minutes power returns and for the duration of my plowing, sometime many hours, things work fine. Next time out be it the next day or the next week same thing happens.Almost acts like a circuit breaker is tripping and then resetting itself, but to my knowledge all circuits are fused.Have checked for loose, broken wires etc but am still at a loss. Anyone have any idea??
Thanks


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## LON (Aug 20, 2006)

where is the red ignition accessory wire tap? Hopefully out in the power distribution box.


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## RoCo (Jan 16, 2011)

YES The red wire goes into the under hood fuse distribution panel and is connectted to fuse #54 Labeled as SEO Upfitter Usage. This OK?


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## no lead (Dec 10, 2008)

i say loose connection at the solenoid or battery. it will work for a few minutes and then heat up. as resistance rises it will stop working. tight connections are a must.


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## stacks04 (Jan 22, 2008)

Also check the light harness connection at the plow. The iirc 9 or 11 pin connector you plug from the truck to the plow. If that one is not plugged in/losing connection you will get the same symptoms as you are describing. Maybe a loose terminal or its getting wet. Use some di-electric grease on those connectors


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## RoCo (Jan 16, 2011)

Thanks for all the tips, Have checked everything as suggested, and nothing notable stands out. Another storm tomorrow so we will see. BTW does anyone have or know where I can get a schematic of Fisher's Joystick Controller. Not talking wiring diagram or pin-outs but an actual schematic of this unit.


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## ETMegabyte (Nov 11, 2009)

RoCo;1201276 said:


> Thanks for all the tips, Have checked everything as suggested, and nothing notable stands out. Another storm tomorrow so we will see. BTW does anyone have or know where I can get a schematic of Fisher's Joystick Controller. Not talking wiring diagram or pin-outs but an actual schematic of this unit.


I am not a pro, however logic states that the problem is probably NOT in the joystick. Nothing about the DRLs have anything to do with the joystick... To me, it sounds like a loose or corroded ground to either the isolation module under the hood, or the light harness...

My experience is that if there is a problem with the light harness, it will give you the symptoms you describe. It being connected disables the stock DRLs in your truck, but lack of power to that harness disables the plow frame's DRLs. If there's no power to the light harness, the joystick will power down, as it gets it's signal from that harness as well... So, to sum up, it sounds like power is being interrupted going to the light harness, which means either a bad ground on the harness itself, or a problem with your isolation module...

Fisher's website has both schematics and exploded views of all of their parts... I'm not sure if it gets into as much detail as you would like, but I would start there...


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## RoCo (Jan 16, 2011)

OK Thanks ET. I'll check into Fisher's stuff again, been there already and didn't find what I was looking for. I was told by a GM mechanic there was a auto reset circuit breaker inside the joystick controller, and this may be causing my problem. The really weird thing thing is it only happen when I first start out. Does its die thing, wait 5 min, powers back up and all is cool. Thought something was overheating, perhaps in that control.Hard to imagine anything corroded, (truck and plow bought new May 2010) loose maybe, but I checked as many connections as I could find. Perhaps a bad module, but I would think the problem wouldn't just go away by itself.


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## stacks04 (Jan 22, 2008)

There is a fuse in the controller not a breaker iirc.


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## RoCo (Jan 16, 2011)

OK guys go figure...had a long trip, so took off the plow, put it back on when I got home and since then the problem that I was having has seemed to disappear. So whatever was wrong has fixed itself, if I had to guess, I'd say a bad/loose ground circuit someplace...or maybe just "ghosts in the machine"


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