Pulled a fuse on my B7800 and engine quit running.

[Hodgy]

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Tractor was running and I was trying to find a blown fuse suppling power to the cab fuse box. I was tracing wires and thought one of these two 30 amp fuses could be the problem. I pulled the pink one on the top of the photo and the engine quit running. I checked both fuses and they are OK.

I plugged them back in, the starter cranks but the engine does not start. Any ideas ?

Here is a Youtube video with photos showing the two fuses.


https://www.youtube.com/watch?v=jC2RhhlIIJs

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[North Idaho Wolfman]

Someone has done some serious "rewiring".
Factory wiring only has one fuse on the main power off the starter, I couldn't tell you what they have added to it.

Normally there is only one thing that stops it from starting, the fuel solenoid.
It gets input from the OPC, you probably cut power to the OPC.

Your going to have to find out what the wire, that you pulled off of, does in order to figured out what you cut power to.

 

[Hodgy]

Someone has done some serious "rewiring".
Factory wiring only has one fuse on the main power off the starter, I couldn't tell you what they have added to it.

Normally there is only one thing that stops it from starting, the fuel solenoid.
It gets input from the OPC, you probably cut power to the OPC.

Your going to have to find out what the wire, that you pulled off of, does in order to figured out what you cut power to.

What is the OPC and where is it located ?


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[North Idaho Wolfman]

What is the OPC and where is it located ?


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The OPC is an occupancy computer that takes all of the safety inputs and allows the tractor to crank and run.

It's located under the dash, there is two different versions of it for that model.

 

[Hodgy]

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I found the problem. I focused on no power getting to the fuel shut off solenoid like you said. I looked at the fuse box on the firewall and checked the 30 amp fuse marked solenoid, it was good. I turned on the ignition key and went and pulled that fuse, when I did I heard the solenoid click. The previous owner had inserted a sucker terminal on the "out side" of the fuse and there was a lost connection for power going to the solenoid. I pulled the sucker tab and cleaned up everything, replaced the fuse and the engine started. FIXED !


Everyone thanks for the help.

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[D2Cat]

Hodgy, good that you got it isolated and fixed. What is a "sucker terminal"?

 

[Hodgy]

Hodgy, good that you got it isolated and fixed. What is a "sucker terminal"?

Correct terminology is "fuse tap connectors".


https://www.wiringproducts.com/fuse-tap-connectors


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[Henro]

The OPC is an occupancy computer that takes all of the safety inputs and allows the tractor to crank and run.

It's located under the dash, there is two different versions of it for that model.

Just a followup question. Glad the OP got his issue resolved.

The B7800 is the Economy version of the B2910 if I remember correctly. I have a B2910 that is a couple years older than the OP's tractor, probably bought it in 2004.

Am I correct in understanding there is a black box somewhere that is called the OPC that is actually a computer? Wasn't aware of this...

 

[North Idaho Wolfman]

Am I correct in understanding there is a black box somewhere that is called the OPC that is actually a computer? Wasn't aware of this...

You are thinking of a B7500 maybe, the B7800 is newer and offered more options than a B2910.


Maybe on the OPC, there are 2 versions of the b2910 models wiring, one version does and one version does not.

 

[Hodgy]

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While trying to find a answer over the last two days I came across this thread from 6 years ago. It goes deep into many problems you could run into with the fuel solenoid not operating. I read the whole thing, very good info in there like there is a relay in the dash that controls the solenoid.


https://www.orangetractortalks.com/forums/showthread.php?t=12167


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[Henro]

You are thinking of a B7500 maybe, the B7800 is newer and offered more options than a B2910.


Maybe on the OPC, there are 2 versions of the b2910 models wiring, one version does and one version does not.

No, I specifically remember the B7800 appearing after I bought my B2910, and that it was more of a no frills model, essentially the same tractor but missing the extendable 3PH links, cruise control, and had a simpler seat. Maybe some other things like the tilt steering wheel were down graded...it has been a while...

The B7800 definitely had less options than the B2910. At least my memory tells me it did.

But memory is the second thing to go, isn’t it?

No doubt the B7800 being slightly newer could have a computer module. For all I know my B2910 may also. Have to see if I can find my workshop manual. Perhaps the wiring diagram will show it.

 

[Hodgy]

No, I specifically remember the B7800 appearing after I bought my B2910, and that it was more of a no frills model, essentially the same tractor but missing the extendable 3PH links, cruise control, and had a simpler seat. Maybe some other things like the tilt steering wheel were down graded...it has been a while...

The B7800 definitely had less options than the B2910. At least my memory tells me it did.

My B7800 has no extendable 3 PTH links and no tilt steering. It has a rudimentary manual cruise control lever down by the parking brake lock. It however does not lock in high speed and creeps back up thus slowing the tractor.

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