Husqvarna RZ5424 with Kohler SV725-3026

[Andi]

Hello all! I have a bit of a conundrum...help?

I have a question. My son (he's learning) went to replace the starter solenoid and did not make note of how the wiring connected. I replaced the entire harness because he connected the single black wire to the positive, and well...Anyhow,

My RZ5424 does not have lights. My unit came with 2 battery pos (one to the solenoid and from there to starter) and the battery neg connected to the other solenoid stud. On the harness, (together in one offshoot) there is the yellow wire to the solenoid tang, the red lead to battery + lead...and then there is a single black wire. it reads 12.34v when the battery is connected, but it sure does not go to the solenoid or the engine ground. The Husqvarna schematic was not updated when the harness was. Does anyone know where that black wire is supposed to go?

Before he fried the harness, I taped off the black wire and it started.

I have also replaced all switches (except the steering interlocks) plugs and both coils. BUT something must be open...somewhere. I get no click, nothing whatsoever. When I replaced the coils this morning, I cleaned the pick-up and made sure the coils were the correct spacing, and I can turn the engine by hand. I have been doing electrical work for 20 years (we have a 73 MCI bus that is a home on wheels) but I am stumped on this.

 

[bertsmobile1]

Should not have needed to replace the entire harness, just the wires between the solenoid & the battery,
Have you replaced the fuses ?
usually a backwards connected battery just blows the fuse.
Plain black wires are always ground so if you have battery voltage on it you have a wire in the wrong place.
With the exception of the cranking circuit all the other wires are ground wires and all switching is done via ground wires.
Very important
The magneto coils have a timing chip in them.
If this ever see battery voltage it will get fried.
So start by pulling the kill wires off the coils to prevent them accidentially getting voltage
From there, start at the battery side of the solenoid and check for battery voltage.
Do the same with the thin wire that goes from the solenoid battery cable to the B terminal on the ignition switch via a fuse.
This wire is usually red or red / black.

It connects to the yellow wire that passes through to PTO switch, both lap bars then the Brake Switch & finally the yellow trigger wire to the solenoid.

 

[Hammermechanicman]

Are you saying when you turn the key the engine does not crank?
Dows the starter solenoid have 3 or 4 terminals?
When you say harness was it the engine or mower wiring or both?

 

[Andi]

The engine does not crank...the solenoid does not click
Fuses are both good.
OEM was 3 wire solenoid. I have a few spares...3 and 4 terminal, but now there is a 3 wire solenoid on it.
I replaced the mower harness because there were wires melted under the conduit, and it was easier than fixing every inch of wire. The engine harness is okay.

The schematic shows...and the wiring matches...red/blk wire goes to "B" (with a red/blk jumper to "A2"), then to 20A fuse, then to battery connect (via the small connector on the + cable) then to ground. It shows a separate ground than the switch that is grounded at the engine bolt. But when I ground the black wire,...nothing happens.

What the schematic does not show is the battery to solenoid cable connections... and the harness was revised on 7/26/12 per manufacturer. It shows a yellow tang wire on the solenoid (that goes to the brake switch) and then to ground.
It also shows 2 accessory outlets (lights that I do not have), I only have one acc outlet with 2 blk and a yellow/blk, and three engine grounds, I only have 2.

I have 12.32 volts at every connection point that should have voltage. That little black wire also has 12.32 volts, hence my frustration because the harness is otherwise simple plug and go. Everything matched up to the original.
And the switch is grounded to the engine frame, with the PTO. So my problem must be the red/blk circuit or the solenoid...but the red/blk should be grounded by the switch, no?

I sincerely appreciate your help. I have 214 circuits that each run 40' on the bus. The only difference is the bus is 24V- (and to reverse the polarity is to kill them all) and the mower is 12V- and I can't figure this mower out.

 

[Andi]

UPDATE
Just to be redundant, I did pull the kill wires off my new coils
I went out and re-checked the small red wire on the battery + terminal...12.32V
BUT...that small black wire no longer has voltage. So, where does it go to ground it?
There was no key in the ignition...should that red/blk wire "B" have voltage with no key?...oh, yes it should as it connects to the battery via the small red connector on the cable. Sorry.

 

[AVB]

What puzzling me why there was voltage on the ground circuit especially you the wires off the ignition coils. This may fried the ignition coils as they no protection from voltage being applied to kill terminal which is grounded to kill the ignition.

Trace and check the starter circuit. Yellow wire. You could fire one of the switches and voltage is no getting to the starter solenoid trigger terminal. First have the ignition that output 12v when in the start position on the "S" terminal. From the wiring goes to the PTO (must have continuity across the two yellow wire terminals with the switch in the off position. From there the wiring to both of the control/motion arms, again continuity across each yellow terminal in park/neutral position. Next stop would be the brake switch. here you looking for continuity across the two yellow wire terminal with the brake set. Last check would the starter solenoid terminal. Here you simply check for voltage if the all the other connections and switches are okay by engaging the ignition switch start position. Note with the mower having a three solenoid you have two large posts and one small one with solenoid metal mounting being the return ground for the solenoid.

Hopefully this makes sense of the wiring. But you may also need someone that familiar with mower wiring to help out on site. I have been doing electrical for quiet a few years but I still need a hands approach on some wiring problems.

 

[Andi]

What puzzling me why there was voltage on the ground circuit especially you the wires off the ignition coils. This may fried the ignition coils as they no protection from voltage being applied to kill terminal which is grounded to kill the ignition.

Trace and check the starter circuit. Yellow wire. You could fire one of the switches and voltage is no getting to the starter solenoid trigger terminal. First have the ignition that output 12v when in the start position on the "S" terminal. From the wiring goes to the PTO (must have continuity across the two yellow wire terminals with the switch in the off position. From there the wiring to both of the control/motion arms, again continuity across each yellow terminal in park/neutral position. Next stop would be the brake switch. here you looking for continuity across the two yellow wire terminal with the brake set. Last check would the starter solenoid terminal. Here you simply check for voltage if the all the other connections and switches are okay by engaging the ignition switch start position. Note with the mower having a three solenoid you have two large posts and one small one with solenoid metal mounting being the return ground for the solenoid.

Hopefully this makes sense of the wiring. But you may also need someone that familiar with mower wiring to help out on site. I have been doing electrical for quiet a few years but I still need a hands approach on some wiring problems.

There is no voltage on that black wire as of now. All that is disconnected at this point, is the starter and the white coil kill wires.
Also of note...the ignition switch does not want to seat all the way...3 of them all OEM Husqvarna, BUT the connectors are contacting the switch.

 

[bertsmobile1]

When faced with problems like yours on ZTR's I use a pile of short jumper leads to bypass each switch one at a time.
I will guess that one of the double switches ( or switch plugs ) that has both a power circuit ( cranking circuit = yellow wires ) and a safety circuit has shorted so the power is being connected to the ground.
So pull the key switch and jump from the B to the S terminal then go look for power where there should not be any.

 

[Andi]

Okay...BEFORE I jumped B to S...I took the batt - off the solenoid (Attached it to frame) and put the starter wire on that post. I also connected the little black "mystery" wire to the frame. The starter had 0 voltage but the batt + and the yellow tag had 12.32 volts. Is solenoid not powering from one side to the other? But when the battery - is there, the starter has voltage. Anyhoo...

I jumped B to S. Had voltage on the yellow lines, including at solenoid, no voltage on white wires at the brake, PTO or either lap switch.

 

[Andi]

By the way, the engine manual makes the following suggestion...that I have NOT tried yet:

"Locate connectors where wiring harnesses from engine and equipment are joined. Separate connectors and
remove white kill lead from engine connector. Rejoin connectors and position or insulate kill lead terminal so it
cannot touch ground. Try to start engine to verify whether reported problem is still present"