# Shielded Wire for AC bundled with DC wires?



## t-craw (Feb 23, 2014)

I've noticed I've been getting weird readings from the Stator Wires coming out of wiring harness at the Regulator/Rectifier end.

I made up a new wiring harness for a Gravely and used mostly 14 ga wire, aside from the battery wire and start wire from solenoid, which are 12 ga. I used typical stranded wire as you would use when wiring a shop or something. It's got the hard insulation (oil and gas resistant). However, I bundled *ALL* the wires together when running down the frame. 

The 2 stator wires from pigtail (hot side of stator coming out of bearing plate) go into this harness AFTER the pigtail plug. They run next to all the other DC wires and exit right before entering the regulator/rectifier.

I can unplug the hot side of stator at pigtail, take a reading and it reads just fine. However, when I plug it back into harness and check it at the other end where it exits to plug into the regulator/rectifier, I get higher AC readings with spiking/noise.

Decided to cut 2 pieces of wire and run them separate from harness and check readings at end. Checks out exactly like it did at the pigtail (no higher readings or noise).

This solved my problem but has me wondering about shielding these AC wires from stator. Especially if I run it along side other DC wires in harness.

Am I good using this existing wire if I keep it separate or should I consider using a special shielded wire?


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## Beaner2u (Jan 9, 2014)

t-craw, 

I hope your work shop/garage is not under a set of High Tension Power Lines. Your readings just do not sound right to me. I am not saying you took the readings wrong, but something is fishy.

The AC charging current coming from the stator has got to be less than two amps, and fourteen gage wire can handle that amount of current easily. You mention replacing a wiring harness, did you also replace the connector, those between the stator and wire run to the rectifier/regulator? And what about the wire run back to the + side of the starter solenoid?

There is no need for shielded wires on a Gravely tractor, promise!

I forgot where you started with this thread. Are you still using the original key switch?

Old key switches are the cause of most electrical problems on Gravely tractors, hands down.

The key switch has to bring power from the + side of the starter solenoid and then send it back to the starter solenoid small terminal for starting; but it also provides a return charging path from the rectifier/regulator back to the battery. 

The starter solenoid current to the starter itself is heavy, that wiring should be four or six guage, almost as heavy as battery cables.

Roger,


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## t-craw (Feb 23, 2014)

Yes, fishy. Couldn't figure it out either but it is what it is, so get ready for a long description.

I made up a new wiring harness and used the existing black plastic connector holders, just replaced the terminals inside them with new ones. All connections to terminal ends were good and snug as well as connections to components.

Used new wire. At first I used all 12 ga. wire for everything. Of course, battery cables are both 4 gauge. Solenoid to starter is the original cable (4 or 6 gauge-did not change this). New correct key switch as well (Kohler p/n 019223) but new wire was used and all the wires were taped together and would exit harness at appropriate locations (ie: stator leads that plugged into stator pigtail, stator leads that plugged into regulator/rectifier) but all along the frame from mid engine to solenoid, these wires were all taped together in one run. 

After installing and re-building engine, I started it up. Later on I started doing some electrical testing..., I had VERY low readings from stator output. Discovered 2 magnets inside flywheel were incorrectly re-glued by the owner. Addressed that and put them in correct order. 

After that I was getting readings from stator pigtail but these readings were spiking erratically very high and low in AC voltage ranging from 18 - 80+ volts AC. Removed stator, cleaned mating surface and provided a good ground then re-assembled (that problem was definitely due to bad ground where stator mounts to aluminum bearing plate). 

Re-checked at stator pigtail and was getting good steady readings that varied with RPM but it was good and steady AC readings ranging from 28-37 volts depending on RPMs. However, when I unplugged these two leads from reg/rect I would get higher readings than when checking at pigtail and erratic spikes in these readings were present as well (ranging from 32-86 volts AC).

I could not figure out why this was happening. I kept going back and forth double checking readings at both ends and I kept getting these weird differences. At this point I decided to take 2 pieces of 14 ga wire (new wire off the spool), crimp connectors at ends and run two wires straight from pigtail of stator to reg/rect. I was now running smaller gauge wire and was separated from the harness. 

Guess what? I had the same reading at far end (reg/rect) as I did at the stator pigtail. No higher readings and no spikes. So..., I kind of thought perhaps the gauge of wire could be causing this???

I pulled wiring harness and replaced the 12 ga wires from stator pigtail to reg/rectifier, the B+ wire from reg/rect to key switch and the +coil wire from key switch, all with 14 ga wire. Taped it all back up into one bundle (just like before with the 12 ga wire) and re-ran it. Hooked everything back up, started it and checked readings once again.
I was back to where I started. Still good readings at stator pigtail but higher readings with spikes at other end that plugs into reg/rect.

Almost pulled my hair out at this point. But..., I retrieved the two 14 ga test wires I had used earlier and tried it again (just 2 wires running from pigtail to reg/rect, separated from wiring harness). Again..., good readings at both ends (no variance and no spikes).

I then tried something else (mind you I'm just brainstorming here and experimenting). I taped these two wires together but still kept them separated from wiring harness. Checked readings again and they were still good.

It was then that I came to the conclusion that I was getting some kind of inductance from the D/C wires that were "bleeding" over into the A/C wires... or vice-versa because of being tightly bundled all together. ??? Nonetheless, I am not getting those different readings any longer. I now have the two AC wires from stator traveling along, separated from the other wires in main harness and tying back into plastic connector that plugs into reg/rectifier. The B+ wire that leaves reg/rect and goes back to key switch is still bundled among the other DC wires in main harness. The only thing that is separated from this main harness now is these two stator wires, taped together, that run from pigtail to regulator/rectifier.

I don't know what kind of wire was originally used on these engines. I do notice that the stator wires that come straight off stator and terminates at pigtail have a thicker, rubbery type insulation around them as opposed to what I am using in my non oem wiring harness.

As I said... it is what it is. Don't know why but I'm getting the correct readings now after all this frustration and experimentation... and frankly, I'm as happy as can be right now.


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## t-craw (Feb 23, 2014)

Just a thought. What if the wiring harness (as it leaves key switch) would touch or vibrate against the high tension lead for spark plug. Would this cause erratic readings anywhere down the line in the wiring harness?


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## Beaner2u (Jan 9, 2014)

I was wrong about the AC current from the stator, yours is a fifteen amp circuit, I was thinking about current with a charged battery.

If your wire harness is routed close to the spark plug wire, that may be giving you the erratic readings. Just for giggles, wrap some aluminum foil around the wires near the spark plug wire, see what happens. Does the spark plug wire check good with an ohmmeter, is it a solid wire unit? Not a carbon wire?

What type of meter are you using? A digital? I went back to an old Simpson 260, watching the swing of an analog meter tells me more than the numbers jumping around on a digital meter. If an analog needle is jumping around, that is usually a connection problem.

Roger,


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## t-craw (Feb 23, 2014)

Have not wrapped harness with foil yet. I clipped the wires at terminals where it exits harness for pigtail and regulator. Would have to re-attach terminals to pigtail end in order to do that little trick and just don't have time for that right now (getting ready to go camping).

Regarding spark plug wire. It's a copper core wire and it checks good with digital ohm meter (yes... I've got a digital multi-tester) and insulation looks good with no cracks visible, however, it would probably benefit by getting a new wire anyway. 

I agree about the analog type tester. It's a good idea to have one around.

Right now I'm satisfied with how I've got things routed and the readings I'm getting. Expect a NEW reg/rectifier to be here tomorrow. Will install, finish breaking in and perhaps when I get back from trip I'll re-wire and wrap with foil just to see if it makes the difference.


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## Beaner2u (Jan 9, 2014)

I remember lifting the hood at night on an old car, the spark plug wires were just a wild light show, but the motor was running OK.


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