782 electric info needed

[pballard]

Hi guys, I need to ask opinions on my current project, it is a 782 that had a Mag18 in it that had seen better days, I found a 2185 that had a good CH18 in it that I have swapped into it and I am currently looking to get some info on how the 2185 was wired. I see the PTO is wired direct with the positive and the ground side is switched, is there a good reason for this, I can see some positive reasons but I think the negative ones dictate not to do this. My plan was to use the wiring from the 2185 but I don't think I like the way the PTO is being operated. so I am contemplating removing the current PTO circuit and doing a re-wire thru a relay switching the positive side - any thoughts either way?
also need to ask if anyone has done this swap. My throttle cable is about a foot short, any part number info would also be appreciated
thanks in advance - pete

 

[jchamberlin]

Pete: I have not done the motor swap you've completed (good work, by-the-way), but theoretically, it shouldn't matter on which side of the load the circuit is switched -in my opinion. Automobiles wiring circuits frequently switch the ground rather than the hot. I'm not sure what the "good reason" is, perhaps someone with more experience or insight will drop by to enlighten us all.

.

 

[nbextermueller]

It's done "backwards" to prevent accidental engagement. When you put a constant ground and switch the power, any accidental "powering" of the hot wire will engage the PTO. If the ground is switched, it can't engage even if something goes wrong with the power side or the relay is dead on the ground side. But since they don't wanted to double switch it and use twice the parts. I assume the power is just run straight in. It's also "easier on relays to not have to run the amperage through it.

Ideally, you'd switch both sides for ultimate safety. Think of it like the lights in your house. (Even though its AC) Power is always running to the bulb. By flipping the switch, your actually just connecting the common side. Or what's known as the ground in DC current.

Either way is really fine in this application.

 

[pballard]

THAMKS FOR YOUR INPUT!