1997 EZ GO DCS with Alltrax XCT48400 and MZJ400

[C Mitchell]

First post here. Have tried a search of the forum, but have not found a specific answer to my question. Here goes:

As stated, 1997 EZ GO 36 volt with DCS. Has a tow/run switch and a F/R lever under the seat. After a couple years of use by me, quit running, bought an Alltrax XCT48400 controller and a MZJ400 solenoid.

Had some problems after install, mostly due to having the regen diode with the stripe oriented toward the B+ on the controller instead toward the B+ on the battery. Blew several diodes before figuring that out. Meanwhile, I also replaced the throttle sensor and the micro switch, as well as the tow/run switch. I did find a loose connection on the micro switch, and perhaps on one spade terminal and adapter on the positive small terminal on the solenoid, which I replaced with a ring terminal.

After all this, no go. Got an error code - green followed by five reds, identified in the manual as a pre-charge failure. I get this error code when I first turn the key on, and also the solenoid does not click when I give it some throttle. BUT, if I move the tow/run switch to tow, then back to run, the error code is cleared, the solenoid clicks, and I can drive it wherever I want to go. This, until I turn the key off. Once I do, then I get no click when turning the key back on, whether I turn it back on immediately or wait ten minutes, or wait overnight. Flipping the two/run switch off then on fixes it.

My MJZ 400 came with a green pre-charge resistor and a short diode. The Carts Unlimited You Tube tutorial shows both of these hooked up on this solenoid.

However, the Alltrax manual states that for my DCS cart, the pre-charge is handled through the tow/run switch (one reason I replaced the tow/run switch). I have only the regen diode connecting the two large terminals.

Online pix of the MJZ 400 solenoid show it having the long regen diode connecting the two large terminals, with a shorter diode connecting the two small terminals. Even the Alltrax instructions for installing the regen diode has a picture of the MJZ 400 controller with the long regen diode connecting the two large terminals and a short diode connecting the small terminals of the 400 solenoid. But the written instructions make no mention of the short diode.

So my questions are: 1. Do I need the pre-charge resistor? If so, where do I put the regen diode? 2. If I don't need the pre-charge resistor, and connect the long regen diode to the two large solenoid terminals, do I need the short diode that came with the MJZ 400 solenoid connecting the two small terminals? 3. And finally, does any of this have anything to do with having to turn the tow/run switch off and on to make it all work?

[ojo]

Can't really help with the DCS, but as far as i remember from a Yamaha Alltrax install, the controller has a built in resistor and the diode should attached to the small posts of the solenoid.
With a laptop and Alltrax Toolkit software you'll be able to check anything in realtime, very helpful!

[JohnnieB]

Originally Posted by C Mitchell

So my questions are:
1. Do I need the pre-charge resistor? If so, where do I put the regen diode?

2. If I don't need the pre-charge resistor, and connect the long regen diode to the two large solenoid terminals, do I need the short diode that came with the MJZ 400 solenoid connecting the two small terminals?

3. And finally, does any of this have anything to do with having to turn the tow/run switch off and on to make it all work?

1. No. Just the regen diode between the large terminals.

2. Yes. The diode between the small terminals helps protect stuff from the voltage spike the solenoid coil generates when it de-energizes.

3. Maybe, maybe not. Your solenoid is not wired right, so you are getting the precharge error code.

There ought to be a red wire connected to the solenoid's battery side large terminal that feeds battery pack voltage to the Run/Tow switch and the beeper 100% of the time. That wire pre-charges the filter capacitors inside the controller.

[binder49]

I had the same problem with my 95 dcs and new xct400dcs. Turned out to be a bad 10 connector attached to the controller. Replaced the connector and haven't had a problem since

[scottyb]

I think I see the problem. The Attrax regen diode appears to be installed correctly indicating the main battery + cable connects to the big terminal at the top of the page. So it looks like all the small red wires for power need to be on the same post. Am I seeing that right?

[C Mitchell]

OK, I'm inside and it's raining now so can't get to my cart, but tomorrow I will connect the two small terminals with the short diode.

As you can see in my pic, I have two red wires that are hooked up to the large terminal that feeds to the controller, not the one that goes to the battery. The EZ GO service parts manual identifies this pair as "wire harness (control)." Your diagram shows one red wire going straight to the solenoid, with another red wire to the battery cable somehow (?). Are these the same red two wires that I have hooked to the controller side? I'm thinking now that I have those two wires on the wrong large terminal. If so, that will be simple to fix.

[C Mitchell]

Originally Posted by scottyb

I think I see the problem. The Attrax regen diode appears to be installed correctly indicating the main battery + cable connects to the big terminal at the top of the page. So it looks like all the small red wires for power need to be on the same post. Am I seeing that right?

You posted this while I was drafting my response above. And yeah, that's what I'm thinking.

I have confused the B+ controller terminal with the B+ battery terminal more than once. Duh. . . .

[C Mitchell]

Okay, made the changes, knock on wood, everything seems to be working well. Thx for all the reponses.

[scottyb]

Good to hear it.

[JohnnieB]