# Fish Stick won't light up - Fisher MM2 HT plow



## 01-7700 (Nov 2, 2014)

Hi, First snow of the season here in Maine, first post as well. I have a fisher mm2 plow. There is power to the plow connector and power to the fish stick connector but when i push the button on the fish stick to turn it on... nothing. Lights work on the plow frame. I store the plow indoors during the off season and it worked when parked last year. Any ideas on what I should be checking? Thanks


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## kimber750 (Sep 19, 2011)

01-7700;1858829 said:


> Hi, First snow of the season here in Maine, first post as well. I have a fisher mm2 plow. There is power to the plow connector and power to the fish stick connector but when i push the button on the fish stick to turn it on... nothing. Lights work on the plow frame. I store the plow indoors during the off season and it worked when parked last year. Any ideas on what I should be checking? Thanks


Is control back lit when plow is hooked up? Is this a new to you plow? Fleet flex? Not sure if HT is offered in fleet flex. You should have one fuse under the dash, two out under the hood and fleet flex has two out on the pump.


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## 01-7700 (Nov 2, 2014)

Thanks for the response. I have used this plow for 4 years on the same truck, not fleet flex. I don't think the control is back lit - I will go out and check again. There are no fuses inside the cab, 2 fuses on a dongle connected to the isolation module, both 10 amp. I looked at the fuses earlier and they appear good. I will check continuity on both fuses. I also plugged and replugged both wire harnesses in for the plow multiple times in case of a bad connection.

We've got about 4 inches on the ground so far - an early snow.

Thanks again.


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## kimber750 (Sep 19, 2011)

There should be a single fuse where the control harness is tapped into fuse box. This is the switched ignition source for plow system. Headlights will still work with out this fuse.


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## dieselss (Jan 3, 2008)

Yep, that's what powers the controller as kimber says. Wiggle the wire, make sure it's got good connection at the fuse box


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## 01-7700 (Nov 2, 2014)

ok thanks, i had pretty much given up on this tonight but now that i read your tips i will go back and look for the single fuse - the wiring harness does not show a third fuse but it makes sense to have one at the main power supply - thanks so much for your assistance.

still snowing


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## 01-7700 (Nov 2, 2014)

Another question if you don't mind while I'm out looking for that fuse. This is the wiring diagram showing 2 blade fuses circled in red. There is a roundish connector i pointed at with a question mark. Inside this connector is a thin wire. Is that the remains of some kind of fuse? The wiring diagram shows power coming from the battery, not through the fuse box. On my truck (F150) the fuse box is under the hood and the isolation module is zip tied to the top of the fuse box. I'll go look to see if any wires are coming out of the fuse box to the module. Thanks.


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## dieselss (Jan 3, 2008)

The fuse we are talking about is coming off your trk fuse box inside the cab.


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## 01-7700 (Nov 2, 2014)

ok, looking in the wrong place - i need to trace that red wire to switched accessory - wasted a lot of time


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## kimber750 (Sep 19, 2011)

01-7700;1858939 said:


> ok, looking in the wrong place - i need to trace that red wire to switched accessory - wasted a lot of time


That is fleet flex wiring diagram. And yes you need to trace the "to switched accessory" wire. Should have a fuse inline.


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## 01-7700 (Nov 2, 2014)

Taking another look at the electric problem, I've been straight out all week. The red "to switched accessory" wire does indeed go back through the firewall to the fuse box under the hood. It connects to a 15A fuse using a tab on one side of the stock fuse. The fuse is good and I'm getting power at the fish stick plug, at the plow, everywhere I can check. How common is it for the module or the fish stick to go bad? I don't have any way to test those. The dealer wants me to bring the plow in with the truck. Can the plow be lifted and held without using its own power? The bar and fake head unit look too flimsy to chain the plow up to.


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## dieselss (Jan 3, 2008)

Jack up the plow and "short chain" it


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## 01-7700 (Nov 2, 2014)

Thanks, I'll take it in next week to see if they can figure it out.


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## 01-7700 (Nov 2, 2014)

it was a burnt out isolation module on the plow.... $300 diagnostic and parts.


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