Help identifying wiring issues

[Billy-O]

Ground is very unlikely the problem from the description given by you. The problem is somewhere between where you found 7volts at solenoid going backwards towards the + terminal of battery. More than likely from (and including) the key switch and the solenoid. Please follow Roland's suggestion for once because that advice is a good one. Alternatively, you can try using a jumper wire from many of the various points to where blue wire connects at the solenoid. These points are engine connector (where blue meets orange, brake switch, PTO switch, key switch.

Edit:. When testing with meter, leave the blue wire connected to solenoid.... Since the load will produce the tell tale 7 volts you read with the meter. Otherwise, you'll chasing the problem blind.

[EternalArianne]

Yes I got the correct switch when I replaced it. Roland sent me the wiring diagram for my serial number, doesn't look like there is a fuel solenoid on mine.

So if it's not the ground, then it's something along that orange/blue wire that is causing a drop in voltage under load. I'll try to get out and run through everything once it's not raining again.

[Billy-O]

Originally Posted by ironman

If I'm looking at the correct wire diagram for a 2155,
the blue wire for the solenoid joins up with red and orange wires in the engine connector.
The orange wire brings the voltage into the engine connector after it passes through the brake safety switch and the PTO switch.
The red wire feeds voltage to the fuel solenoid and the PTO.
I would pull the plug off of the fuel solenoid and the PTO and see if the voltage still drops at the starter solenoid when the key is operated.

I THINK that is not the correct wiring diagram based on serial number (362116) provided by the OP. I believe he does not have the electric fuel solenoid where red wire intersects blue and orange at the engine connector. I tried to upload PDF of wiring but it is too large. Here is a link to Cub Cadet wiring diagrams and you will find two versions for the 2155 tractor: https://www.ccpartsnmore.com/cub-cad...ing-schematics

[ironman]

Originally Posted by Billy-O

I THINK that is not the correct wiring diagram based on serial number (362116) provided by the OP. I believe he does not have the electric fuel solenoid where red wire intersects blue and orange at the engine connector. I tried to upload PDF of wiring but it is too large. Here is a link to Cub Cadet wiring diagrams and you will find two versions for the 2155 tractor: https://www.ccpartsnmore.com/cub-cad...ing-schematics

OK, thanks. I did not know his s/n. That definetly simplifies things.

Since we have to assume that there is a poor connection between the key switch and the solenoid lug my conclusion is this......

He claims that the solenoid will not operate when the brake is released or the PTO switch is operated.

That only proves that those switches are functioning as they should by opening the circuit to prevent the solenoid from operating.

However, when the brake is engaged AND the PTO disengaged, the brake safety switch and the PTO should close
and there should be rock solid zero ohm continuity from key switch lug "S" to the solenoid lug.

So until he is willing to take an ohm meter and check that out, we are all wasting our time here.

[EternalArianne]

I am currently trying to figure out how to test the connectors on the PTO and brake switches while they are still plugged in, as it's a moulded connector that covers all the pins. I will see if I can get a small enough probe to stick down where the wires go into the connector.

I'm sorry for wasting everyone's time on this. I will report back once I have isolated the issue. After I get this taken care of, hopefully I won't have any more issues to pester you guys with...

[ol'George]

No time wasted for me, and everyone's questions are important and many learn from the answers.
Lack of knowledge or ignorance is cured by education.
Most all of us enjoy helping and learning.
When one stops learning, they have stopped living.

[ironman]

Didn't mean to ruffle your feathers, but you don't seem to provide the information that we are all looking for in order to help you.

The first and easiest step is to determine if there is indeed a flakey connection BETWEEN the key switch and the solenoid.
To do that.....

1. Remove the blue wire from the solenoid.
2. Set your meter to ohms and zero it.
3. Attach one meter lead to the terminal of the blue wire that you removed from the solenoid.
4. Remove the plug from the rear of the key switch.
5. Determine which terminal within the plug slides on the "S" terminal of the key switch.
(supposedly an orange wire if the wire diagram is correct)
6. Attach the other meter lead to the pin of the plug that slides onto the "S" terminal of the key switch.
(you may have to insert a paper clip or such into the plug to make contact)
7. Look at your meter. You should see zero ohms resistance.
8. Exercise both your brake and PTO switch numerous times while watching your meter.
9. You should always see either zero ohms or infinite ohms (open).
10. If that is the case, you have no problem in your wire path to the solenoid.

If you see more than zero ohms with the brake set on the PTO switch off....
11. Unplug the engine connector.
12. Looking into the connector end that goes back towards the console (not towards the engine) determine which pin,
when plugged together, connects to the blue wire to the solenoid. (supposedly orange wire)
13. Remove your meter lead from the blue solenoid wire and reattach it to the pin you determined in Step 12.
14. Repeat Steps 7 thru 10.

If you still encounter more than zero ohms resistance.....
15. Remove the plug from the rear of the PTO switch.
16. Determine which pin of the connector slides onto pin #1 of the PTO switch (supposedly one of the orange wires).
17. Remove the meter lead from the key switch connector and attach it to the pin of the PTO connector that you determined in Step 16.
18. Exercise your brake. If you see more than zero ohms when the brake is set, your problem is in your brake switch, or more likely the connector.

If you see a good solid zero ohms......
19. Remove the meter leads from the engine connector and the PTO connector.
20. Attach the meter leads across pins #! and #2 of the PTO switch.
21. You should read zero ohms with the PTO switch off, and infinite (open) with it on.
22. Any resistance would indicate a faulty PTO switch.

If all your readings are zero, you do not have a wiring problem.
I hope this helps you, it shouldn't take more than 5 minutes to do versus 15 minutes for me to type it.
Good luck.

p.s. I have worked on a couple of these brake switches.
I know that the switch and connector are almost impossible to get to without tearing half the tractor apart.
One thing to look for is that the metal tab that pushes the plunger in on the brake switch is pushing it completely in when the brake is engaged.
The tab can get bent and not completely depress the plunger.

[EternalArianne]

Looks like the PTO switch is the problem, everything else is 0 resistance. Thanks everyone

[EternalArianne]

I'm at my wits end on this. Replaced the PTO switch and it's STILL doing it! Everything else in Ironmans instructions checked out fine no resistance. PTO switch had resistance so I thought it was the problem but nope.

I'm about ready to wire up a bypass button straight from the battery to the blue wire since I know it will start by jumping 12V to that connector...

[EternalArianne]

I get what you are saying George and I think we are narrowing it down. I've replaced the solenoid, key switch, and PTO switch. At this point it's gotta be either wiring or the brake switch lol. I'll keep digging around with it, I need to get a better (smaller) probe for my volt meter that can fit inside the connectors on these switches while they are still connected.