Intermittent Power Loss When Traveling at Less Than Full Speed

[Singlealt]

So, we ordered the MCOR4 replacement kit mentioned above, and we learned our cart actually had a TPS on it. After confirming the wiring, we replaced the TPS with the MCOR4, but the problem still exists. I don't think the batteries is the problem because we actually just replaced the batteries this summer, and the issue existed before the battery replacement. We've also replaced the solenoid. Any other ideas?

[TahoeDawgZ71]

What's the vehicle serial number?

[Singlealt]

Pq1007-079217

[Sergio]

It sounds like the more uncommon "Main dropout" condition.

The IQ controllers had an issue when the cart engaged the "Regen Brake" to control the speed, it would sometimes depending on the battery charge cause a false error condition.

Club Car came out with a field modification called the "Main dropout" harness for the earlier IQ carts.

They also installed a diode inline with the Controller "Aux Power" for subsequent years until the diode was incorporated into the Controller.

If the existing diode on your circuit (internal or external) has failed, the cart will power OFF the solenoid on certain occasions when the Regen brake is engaged.

[Singlealt]

If the diode is the problem, what would be the solution for that?

[Sergio]

Wait for David (TahoeDawgZ71) to get back on line to see if he has other ideas.

You can still buy the "drop-out harness" from David and it just plugs into the Tow/Run switch connector.

[TahoeDawgZ71]

The "Main Dropout" harness is designed to plug into the connector on the tow/run switch of a DS car. A Precedent doesn't have the correct connector. The early IQ cars are the only ones that need this modification. I suggest checking the voltage on the small solenoid posts (coil activation circuit) while driving. When power is applied to these posts, the solenoid clicks and makes a connection. When power is removed, it disengages or "opens" the connection. What we need to figure out is if the solenoid is being told to disengage by the controller or if it's disengaging on it's own due to a poor internal connection.

[Singlealt]

The first thing we tried when the problem started was replacing the solenoid, but the problem continued. The solenoid doesn't seem to be disengaging when the the power kicks out. You can hear the solenoid when it engages/disengages. Once it stops, you can ease your foot off the pedal, and the solenoid doesn't disengage until it comes off the petal. Then you can press the gas again, and you can hear it reengage.

[TahoeDawgZ71]

Gotcha. Does it slow to a crawl or does it stop completely if you leave your foot on the floor when it fails? If it's slowing to a crawl, it sounds like you have a speed sensor that is beginning to fail.

[Singlealt]

When the power kicks out, it comes to a stop. Sometimes, you can put the pedal to the floor, hold it, and it will take off. However most of the time, you have to completely remove your foot from the pedal for it to go again.