'97 TXT series cart no go, solenoid won't click

[harpj1972]

Hello, I'm Harper and I have a 97 TXT 36V, and I'm fairly positive it's a series cart from looking at diagrams and reading many threads on this forum over the last couple of days. I must tell you I know very little about carts, not to mention I have about the same mechanical ability as a run-over toad. With that being said, I feel like I've read and re-read enough posts by ScottyB, JohnnieB, and yurtle to try and do some troubleshooting. After learning to use the multimeter I've had a couple of years, here's what I found... After fully charging the batteries yesterday and waiting 18+ hours to check voltage, I have 37.9V on battery side of Solenoid, nothing on the controller side. The solenoid doesn't have a resistor or diode on it. I HAD BEEN only getting 15.2V from charger port all the way to the pedal box in the floor, and nothing after that. It was bothering me so just now, in the middle of this post, I went out and changed the red "reed switch" wire going to the F/R switch and got my voltage up to 37.9V all the way thru key switch to the pedal box. This time I had enough voltage to carry thru the pedal box to the solenoid, with 31.1V. Still, no solenoid click. I tried a jumper but still nothing. What should I do next? (Tomorrow, as I must go to bed) I would appreciate any advice. Thanks in advance. Harper

[JohnnieB]

There are two sets of terminals on the solenoid, large ones and small ones.
Disregard the large ones for now. They aren't in the picture until the solenoid clicks.

The 31.1V out of the pedal box is a bit low, but should be enough to activate solenoid.

If the solenoid didn't click when you jumpered Battery pack voltage to the small terminal with the red wire on it, either the solenoid coil is bad, or the black wire from the other small terminal to B- on the controller is bad.

[scottyb]

If you hold the test leads on the 2 small posts, you should read 36v when you press the gas peddle. This is the activation circuit. If you do read 36v there then the solenoid will not click and you need to find which polarity is missing, + or - and fix it

Attached is the series solenoid activation circuit highlighted on the cart wiring diagram.

[harpj1972]

Let me see if I understand what you guys are saying. JohnnieB, I need to run a wire from the 36+ of my battery pack to the small terminal on the solenoid where the red wires attach to try to get it to click? And that would be sending power straight to it so I won't need to press the pedal when doing this, correct? And ScottyB, what exactly do you mean by"finding which polarity is missing and fix it"? Would that mean one of either the red or black wires going to the small posts is bad? I'm sorry if my questions seem redundant, as I am sometimes moronically challenged. My father used to call me his little simpleton.

[harpj1972]

Also, whether this solenoid is ok, or I have to get another, shouldn't it have a resistor and diode on it? Thanks, Harper

[JohnnieB]

Originally Posted by harpj1972

................ This time I had enough voltage to carry thru the pedal box to the solenoid, with 31.1V. Still, no solenoid click. I tried a jumper but still nothing. What should I do next? (Tomorrow, as I must go to bed) I would appreciate any advice. Thanks in advance. Harper

In your original post, you stated you tried a jumper but didn't state what you jumped, nor did you mention the bright flashes of light or clouds of smoke that often accompany the use of jumper wires, so I attempted to define which non-destructing jumping you did and what one of them would have told you if it was, in fact, what you had done.

A jumper wire is not a troubleshooting tool and often cause more problems that they solve.
However, when used with due diligence and with a thorough understanding of exactly what is being done, they can prove or disprove the veracity of a conclusion based on the information provided by a voltmeter and/or other diagnostic test equipment.

If the solenoid clicks when B+ is applied to the red wire via a jumper wire, the problem is in the four switches and their associated wiring and connectors that were bypassed by the jumper wire.
If the solenoid doesn't click, either the solenoid coil is bad or the black wire that supplies B- to the coil is bad.

This same information can be obtained with a voltmeter, without the risk of blowing something up if the wrong place is touched.

-------------
Yes, a diode and resistor should be installed.
In fact, not having the diode is very likely why the pedal microswitch isn't passing the full battery pack voltage to the solenoid.

The resistor protects the solenoid contacts from a huge in-rush of current when they close by keeping the filter capacitors in the controller charged.

The diode protects the pedal switch contacts, or preceding switch that opens and de-energizes the solenoid, from arcing due to the huge voltage spike that is generated when the solenoid coil's magnetic field collapses.

They are not essential for operation, they just help the switch and solenoid contacts last longer.

[harpj1972]

I came home from work this evening, and just for giggles, the first thing I did was read the voltage again at the solenoid where the wire attaches from the pedal box switch. It was 37.9V, not 31.1V....I put my voltmeter on the 2 small posts on the solenoid and pressed the pedal. Any guesses?? CLICK!!! My wheels started spinning for the first time in months!!! And it's been zipping around like a dream ever since. So what happened? What changed between last night when I tested that wire and got 31.1V, and nothing when I hit the pedal, and this evening when it shows full voltage and clicks and runs? Was it the extra voltage from the wire I changed last night, or the touching of the 2 posts with the voltmeter, or just dumb luck??? By the way, thank you, JohnnieB, and ScottyB for your insight and knowledge. I'd like to know what I did right, if I did do it, as this may be the first thing I've ever "fixed" in my life. I hope I didn't just jinx myself.