ZD 326 Electrical problem

[rrleesb]

I have a ZD 326 S, SN 15047 that I'm having an electrical issue with. I'll list the symptoms first then go into the troubleshooting steps that I've completed next. Symptoms are key turned on, no lights turn on and no crank.

I've replaced the starter(key) switch, battery is fully charged with good connections, all fuses have been checked for resistance and good. When doing voltage checks on the starter switch the red wire has 12v when the key is off. As soon as key is switched to on the voltage on the red wire goes to 0 (I'm assuming a short somewhere). The red/yellow wire also has 0v. I've done resistance checks on the new starter switch and it shows that it's working properly as described in the service manual. There are three relays under the seat, horn, start and solenoid. I have pulled all of those and the coils test at ~90 ohms which is near spec and none of the other leads are shorted to each other. I've also pulled the connectors off the relays to test the voltage at the start switch and am getting the same result. I also looked over the wires for any mouse damage, but haven't seen anything obvious.

Additionally, I jumped the terminals on the starter and it ran until it ran out of fuel, so I'm assuming the fuel shut of is closed.

Any ideas where to look or steps to complete to isolate?

 

[jaxs]

Symptoms shout poor connection but you state connection are good so I don't have any other ideas.

 

[GBJeffOH]

I have a ZD 326 S, SN 15047 that I'm having an electrical issue with. I'll list the symptoms first then go into the troubleshooting steps that I've completed next. Symptoms are key turned on, no lights turn on and no crank.

I've replaced the starter switch, battery is fully charged with good connections, all fuses have been checked for resistance and good. When doing voltage checks on the starter switch the red wire has 12v when the key is off. As soon as key is switched to on the voltage on the red wire goes to 0 (I'm assuming a short somewhere). The red/yellow wire also has 0v. I've done resistance checks on the new starter switch and it shows that it's working properly as described in the service manual. There are three relays under the seat, horn, start and solenoid. I have pulled all of those and the coils test at ~90 ohms which is near spec and none of the other leads are shorted to each other. I've also pulled the connectors off the relays to test the voltage at the start switch and am getting the same result. I also looked over the wires for any mouse damage, but haven't seen anything obvious.

Additionally, I jumped the terminals on the starter and it ran until it ran out of fuel, so I'm assuming the fuel shut of is closed.

Any ideas where to look or steps to complete to isolate?

Hook a light or other load to the wire that drops to zero. Then follow the wire with a voltmeter to see where it drops.

 

[mikester]

You have lights and a horn on a ZD326? Are these home brew or an OEM option with proper harness ties? Or are you talking about control panel lights?

Have you checked all the fuses?

No crank usually happens when one of the safety switches is triggered or DOA - seat, hand controls, brake, PTO.

Maybe I'm misreading your post I don't understand why you changed the starter.

 

[rrleesb]

You have lights and a horn on a ZD326? Are these home brew or an OEM option with proper harness ties? Or are you talking about control panel lights?

Have you checked all the fuses?

No crank usually happens when one of the safety switches is triggered or DOA - seat, hand controls, brake, PTO.

Maybe I'm misreading your post I don't understand why you changed the starter.

When I say lights, I mean the indicator lights that turn on when you go to the first position on the key switch. The glow plug light should illuminate when turned to the next spot as well. None of those lights are turning on. No aftermarket lights or horn. The horn is just the buzzer that sounds when overtemp.

All fuses have been checked for resistance.

 

[rrleesb]

You have lights and a horn on a ZD326? Are these home brew or an OEM option with proper harness ties? Or are you talking about control panel lights?

Have you checked all the fuses?

No crank usually happens when one of the safety switches is triggered or DOA - seat, hand controls, brake, PTO.

Maybe I'm misreading your post I don't understand why you changed the starter.

I changed the key switch.

 

[TheOldHokie]

I have a ZD 326 S, SN 15047 that I'm having an electrical issue with. I'll list the symptoms first then go into the troubleshooting steps that I've completed next. Symptoms are key turned on, no lights turn on and no crank.

I've replaced the starter(key) switch, battery is fully charged with good connections, all fuses have been checked for resistance and good. When doing voltage checks on the starter switch the red wire has 12v when the key is off. As soon as key is switched to on the voltage on the red wire goes to 0 (I'm assuming a short somewhere). The red/yellow wire also has 0v. I've done resistance checks on the new starter switch and it shows that it's working properly as described in the service manual. There are three relays under the seat, horn, start and solenoid. I have pulled all of those and the coils test at ~90 ohms which is near spec and none of the other leads are shorted to each other. I've also pulled the connectors off the relays to test the voltage at the start switch and am getting the same result. I also looked over the wires for any mouse damage, but haven't seen anything obvious.

Additionally, I jumped the terminals on the starter and it ran until it ran out of fuel, so I'm assuming the fuel shut of is closed.

Any ideas where to look or steps to complete to isolate?

If the red wire tests 12v with switch off and drops to zero as soon as you switch in a small load (lamp test) the battery is defective or the connection is bad. I suggest you load test the battery

Dan

 

[GreensvilleJay]

replace the lousy battery cable(s) AND improve the ground connection.
NOT a 'short'.
'shorts' allow a LOT of current to flow and will blow fuses, melt wires,etc.
What you describe ( 12v at starter until key turned, then zero ) is 'classic' high resistance cable. The 'core' of the high current battery cable has 'rotted' (corroded) and it's not a high value resistor. Able to pass a small current ,maybe a few milliamps but not amps.

Also....While most will clean up the frame surface where the ground wire gets bolted to, very,very few actually clean the face of the bolt that attaches cable to the frame. 1/2 or more of the current flows through that 'connection'.

 

[rrleesb]

replace the lousy battery cable(s) AND improve the ground connection.
NOT a 'short'.
'shorts' allow a LOT of current to flow and will blow fuses, melt wires,etc.
What you describe ( 12v at starter until key turned, then zero ) is 'classic' high resistance cable. The 'core' of the high current battery cable has 'rotted' (corroded) and it's not a high value resistor. Able to pass a small current ,maybe a few milliamps but not amps.

Also....While most will clean up the frame surface where the ground wire gets bolted to, very,very few actually clean the face of the bolt that attaches cable to the frame. 1/2 or more of the current flows through that 'connection'.

I'll take a look, thanks.

 

[GreensvilleJay]

they can look fine' but rotten 'in the core'. you also can't usually check them with a 'meter' as most DVMs can't read .001 of an Ohm.
sad thing is you may have replaced a perfect starter (unless it failed when tested on the bench ).

 

[TheOldHokie]

I'll take a look, thanks.

Can you clarify where you are probing 12v on the "red wire"? I interpreted that description as the + supply wire coming to the ignition switch and it goes to zero as soon as the switch is moved to the run (not start) position.

Dan

 

[rrleesb]

Can you clarify where you are probing 12v on the "red wire"? I interpreted that description as the + supply wire coming to the ignition switch and it goes to zero as soon as the switch is moved to the run (not start) position.

Dan

Yes, in the back plug of the ignition switch. I pushed my multimeter probe into the connector.

 

[rrleesb]

Cleaned up the grounds at the battery with no change. They looked good to begin with, but I did it anyway.

 

[TheOldHokie]

Cleaned up the grounds at the battery with no change. They looked good to begin with, but I did it anyway.

You are getting voltage at the key seitch with the key off but a voltmeter draws close to zero current. As soon as you turn the key to run the instrument panel load tries to draw current and the + connection is so bad that drops voltage to zero. There is not enough current to even illuminate the panel lights. This has nothing to do with the starting circuit. Clean all the positive battery connections between the battery and the key switch. My bet is the + battery post connection or the connection for the key switch wire is the problem.

Dan

 

[GreensvilleJay]

If I'm looking at the pictures properly...

the battery -ve goes to a stud on the frame, then another cable from there to front of frame, where the engine is mounted.

That's NUTS........

-ve of battery should be connected to the engine block using ONE cable. You should be able to find a good sized stud/bolt that you cann attach the cable to.


Also that 2nd cable has exposed ends,so moisture WILL get into the core of the cable and rot it from the inside out ( looks 'good' )

 

[TheOldHokie]

If I'm looking at the pictures properly...

the battery -ve goes to a stud on the frame, then another cable from there to front of frame, where the engine is mounted.

That's NUTS........

-ve of battery should be connected to the engine block using ONE cable. You should be able to find a good sized stud/bolt that you cann attach the cable to.


Also that 2nd cable has exposed ends,so moisture WILL get into the core of the cable and rot it from the inside out ( looks 'good' )

That's the way both my G's and a couple of my cars are built. Works fine for me.

Dan

 

[whitetiger]

Additionally, I jumped the terminals on the starter and it ran until it ran out of fuel, so I'm assuming the fuel shut of is closed.

That would indicate the battery and battery cables are fine, your problem is with the power coming from the wire with the slow blow fuse at the starter to the Key switch.
Use your meter and check for voltage on both sides of the slow blow fuse and the connector laying on the deck lift cylinder under the seat. These would be the most common areas for a loose or corroded pin.

 

[lugbolt]

When doing voltage checks on the starter switch the red wire has 12v when the key is off. As soon as key is switched to on the voltage on the red wire goes to 0

Any ideas where to look or steps to complete to isolate?

This is exactly where a voltage drop test can save HOURS of frustration. YouTube search it and learn how to do it, and you'll find the problem fairly quickly.

 

[rrleesb]

That would indicate the battery and battery cables are fine, your problem is with the power coming from the wire with the slow blow fuse at the starter to the Key switch.
Use your meter and check for voltage on both sides of the slow blow fuse and the connector laying on the deck lift cylinder under the seat. These would be the most common areas for a loose or corroded pin.

Thanks for all the help with this fellas. I pulled the loom apart from the starter to the key switch and found the broken/corroded connection. It was just below the relay box under the seat for others that have the same issue. I cut back to clean copper and soldered it back together.

Got it all running then poked a wire through the sidewall of the tire. Can't win around here.

 

[TheOldHokie]

Thanks for all the help with this fellas. I pulled the loom apart from the starter to the key switch and found the broken/corroded connection.

Easy peasy

Dan