Cart off - pre-charge resistor warm????

[93yellowclubcar]

93 CC 48 volt 700 amp FSIP and super duty solenoid. Cart sat all night and all day today - pre-charge resistor is warm! Everything else is cool to the touch but the resistor. V-glide returns all the way down, MS is good, nothing seems wrong. Key was off and cart was in neutral. Is this normal?

[scooterman]

Check the F/R switch, also test voltage across the resistor with everything off and then on, post results. Hard for me to trace exactly from the schematics here but from what I see. There shouldn't be anything across it with everything off. This looks to be a converted cart from resistors to electronic right?

[93yellowclubcar]

Factory 93 controller cart that was upgraded.

I have 50.0 volts on the "hot" side of the solenoid and 28.6 on the other! What the heck?

[scooterman]

What does that mean? From what two point are you measuring the voltage?

[93yellowclubcar]

From pack negative to the side of the solenoid the main positive cable runs to I have 50.0 volts (pack voltage). From pack negative to the other large post I have 28.6 volts.

21.3 volts with one probe on each solenoid terminal.

[Sergio]

If You pull the connector from the controller #1 (+48v key switch) terminal and the pre-charge resistor still gets hot, that usually means the controller is shot (either capacitors or a blown FET).

[scooterman]

Thanks for that.

This was a conversion, so a few things happened to make this work, the wire harness was either adapted or replaced.
Disconnect one of the wires to the coil terminals(either one of the small ones) and measure from the loose wire to the other wire. If I'm not mistaken, I think there should be nothing there until you trun the key switch and then it should have 50 volts or pack voltage which would energize the coil, thus shifting the contactor and allowing current to flow to the controller. So if this makes sense then it should help you trace out the wiring, hopefully it is an easy fix to the problem. Is the cart functional as always or is there any other issue?

[scooterman]

Originally Posted by Sergio

If You pull the connector from the controller #1 (+48v key switch) terminal and the pre-charge resistor still gets hot, that usually means the controller is shot (either capacitors or a blown FET).

That is what I thought the controller would send power to the coil. Wasn't sure exactly what was done to make the conversion. I was hoping it could of been something simple and not the controller, that is always a shocker to the wallet.

[93yellowclubcar]

Cart functions normally, (or seems to) I just noticed the problem when I happened to brush my hand past the resistor. One other thing - when I measure from B- to M- AND to B+ on the controller I get 28.6 volts.

[Sergio]

You have about 50ma of current flowing pass the resistor which is causing the voltage drop.

It is either going into the controller or directly to the motor.

if it is the controller and there is not +48v on terminal #1, meaning the controller should not be active, that means you have a bad capacitor or an FET.

Since You have the FNR in neutral, the Motor A2 is not connected to anything, so a short motor coil should not cause a problem.

What value (ohms) pre-charge resistor do you have and what is the wattage?