520H Wiring

[rpiazza6857 1]

So I have a 520H I bought a few years back and just recently I have had some issues with the wiring, mainly the 9 pin and the fuse block. I would like to remove the existing fuse block and use inline type fuses, this has already been done on the 30 amp circuit but I'm not sure it was done correctly, I would like to wire the B+ wire with a 30 amp inline to the to the battery + to eliminate that going through the 9 pin as it was burnt. I would also like to wire the two reds with an inline 25 amp as well. The main issue I am having is the wire diagram and what mine has as well as what I have seen on here doesn't jive. The diagram shows the purple wire going to the start relay to be connected in the fuse block to the battery side, in my tractor the wire is white and the previous owner had it wired to an inline fuse but connected to the white wire on the B+ and then had an inline fuse over to the battery side red wire out of the 9 pin. I have seen others fuse boxes in other threads with the two white wires connected but it seems to contradict the wiring diagram. I attached a diagram so hopefully you guys can follow my babbling. I would like to double up the purple wire to the the red wire out of the 9 pin like it was connected in the original fuse block and then run it through the 25 amp fuse which would be red coming out and going to the key switch.  DOC051822.pdf 

Edited May 18, 2022 by rpiazza6857

[Handy Don 12,174]

Welcome to the Forum.

 

Right off the bat, I'd caution you not to rely heavily on the color coding for the wiring. The diagram is reliable for "what connects to what", but it is a schematic. Put another way, I think of the colors as aspirational not gospel. And, as you've seen, a PO may changed things and been less than scrupulous about following either color or the circuit plan.

 

My general approach to rewiring, and what I advise others to follow, is to study the diagram and, unless there is a strong reason to vary, follow the same "what to what" circuits. Bypassing the 9-pin connector or replacing the fuse block with weatherproof inlines fall into this pattern. I never double any wire--I use the correct size wire for the job and remove any unused wiring. I do, as do many other members, add wired grounds instead of relying on the frame or other components--especially for the voltage regulator and lighting. I do clean connections and use dielectric grease to help keep them from corroding in future. I do mark up a paper copy of the diagram while I work.

 

I think most members agree that the 9-pin connector is a weak area (it was there to make connecting a "crate engine" from Kohler to a chassis by WH simpler and faster on the assembly line). Many members have bypassed some or all of the 9-pin connector with direct point-to-point wiring, as you propose, especially for the power from the regulator. Others have simply replaced their damaged connector (available from wheelhorsepartsandmore, under Classifieds/Vendors at the top of the page).

The exposed fuse block is another agreed vulnerable area, especially when the tractor is exposed to weather.

Some members, based on their knowledge and experience, choose to vary from the "factory" wiring plan and you may as well. It is your machine.

 

You sound like you are on the right track. Be sure to take before and after pictures as you work and if you have question post the picture along with it to help us zero in on the issue.

 

Good luck!

 

 

[rpiazza6857 1]

Thanks Handy Don, I agree on not doubling up a wire but unfortunately I cannot figure out any other way, I attached the drawing again, this time circling the original double tap, these two wires are linked in the fuse box creating what I call a double tap. 

DOC051822.pdf

[Handy Don 12,174]

I guess I'm not clear on your definition of a double tap.

In the stock fuse block, there is no "bus" to carry the input across two or more fuses (as you might see in a household circuit breaker panel)--each fuse has its two terminals wired individually. If what you are describing is a jumper linking the inputs of two fuses so that one end of one fuse has two wires attached, that is normal.

 

If you replace the block with inline fuses you'll choose how to wire it. You can do separate (16 ga) runs from the 9-pin (or direct from the battery or solenoid terminal if you choose to bypass the 9-pin) directly to the individual fuses. Alternately, you could use a single, heavier (14 ga gives you plenty of capacity) run that ends spliced to the inputs of the two fuses--whichever makes the neatest result or easiest job for you.

Edited May 18, 2022 by Handy Don

[rpiazza6857 1]

Yes, those two wires are linked in the fuse box, or bussed as your calling it, there is a metal strip connecting both fuses, doing what I would like to do leaves no where for the purple wire to go unless it is tapped into another wire. I'm sure others have done this just not sure exactly how. 

[Handy Don 12,174]

Ok. You are referring to the 12v supply to the starter relay switch. (I don't name wires using colors--remember, I don't trust colors and purple is used in multiple places!)

 

You can directly wire that since it isn't being protected by the fuse. It wired as it is, again, to facilitate the 9-pin connection. Rewire is easy and short since that relay is right next to the solenoid and it'll actually reduce the wiring complexity!

[rpiazza6857 1]

There is the aha answer, in the original diagram it didn't look like it was protected however the way I have seen some fuse boxes on here and how the original owner had it wired it was fuse protected so I was really questioning it. So you are saying I can run this wire to what solenoid since it is just 12v supply for the relay?

[roadapples 6,983]

[953 nut 55,119]

What you intend to do seems reasonable to me, the nine pin is notorious for causing  problems. I would suggest that all joints be soldered and protected with two layers of shrink wrap.

[Handy Don 12,174]

5 hours ago, rpiazza6857 said:

There is the aha answer, in the original diagram it didn't look like it was protected however the way I have seen some fuse boxes on here and how the original owner had it wired it was fuse protected so I was really questioning it. So you are saying I can run this wire to what solenoid since it is just 12v supply for the relay?

Yes.

There is no need to fuse-protect the power to that starter relay switch, per the standard wiring diagram.j

Without knowing the exact specs of the relay, I wouldn't even hazard a guess on what fuse would be appropriate if one were to want to protect it.

Edited May 19, 2022 by Handy Don

[rpiazza6857 1]

I like the idea but could you tell me what solenoid your referring to? The hot lug on the starter solenoid? 

[peter lena 8,588]

@rpiazza6857  agree with others on the wiring details ,  important to eliminate the tight bending wire settings that cause cracking and shorting , CHANGE THE ROUTING , use cable wrap , and hangers as you go , and verify every step . that 9 pin is a mess , insure its not in any binding tight stressed spot . would also enhance electrical grounding , from a verified spot , like battery cable to chassis ground bolt . add an electrical bolt on lug , for an easy add on wire spot . also use serrated washers on frame to ground points , dielectric grease , with all the input you are getting , obvious this is a tough spot . verify as you go , once you get it , its  pretty good . good luck , pete 

[rpiazza6857 1]

Very bad at electrical, but pretty good at cleaning things up, funny you say that currently searching for some wire wrap that is heat rated for an engine bay to get rid of all the split plastic loom originally used, can anyone make any suggestions on that?  

[Handy Don 12,174]

2 hours ago, rpiazza6857 said:

I like the idea but could you tell me what solenoid your referring to? The hot lug on the starter solenoid? 

Yes, the starter solenoid. You'll want to take the power from the terminal where the battery is providing power to the starter solenoid.

 

On a lot of 520's the safety switch relay is right next to the starter solenoid since the safety switch relay closes to allow (your about to be routed) power through to the solenoid only if the the safety criteria (neutral, PTO, etc) have been met.

Edited May 19, 2022 by Handy Don

[lynnmor 7,302]

41 minutes ago, rpiazza6857 said:

Very bad at electrical, but pretty good at cleaning things up, funny you say that currently searching for some wire wrap that is heat rated for an engine bay to get rid of all the split plastic loom originally used, can anyone make any suggestions on that?  

There wasn't a lot of split loom used, maybe the previous owner added some junk.  I never had an issue with the loom, the only heat related problems was bad connections overheating.

[peter lena 8,588]

@rpiazza6857  CABLE WRAP, https://www.bing.com/images/search?view=detailV2&ccid=ysFFJMuU&id=E61CA87A7C4E9330C25F41B734DFF8830311BB1C&thid=OIP.ysFFJMuUb4El8MFMG35lwQH  this the type I  use , along with rerouting ,  would also  emphasize getting air flow and dielectric grease on those multiple connections . most of the failures I have seen were also stress cracked , and powdery electrical cracked , due to wire pull and tight bending .  might even get some engine air flow diversion going for you to insure a cooler connection . good luck with it , pete