Solenoid resistors


New Member
First, I want to say "Thanks" to all for the knowledge that I've gotten off the forums already.
Real learning curve. Parents old cart & am trying to improve it enough to use at the dragstrip for towing a 1200 lb. Front Engine Dragster.
Cart is a '95 EZGO Medalist, 36 volt, ITS, batteries are Trojan 605 with date C 4. Regular controller but have Alltrax 400 on order & plan on -4 welding cable upgrades.
1-there are two resistors on the solenoid, why are they there? Do they need to be there, one friend told me that he did away with the ones he's run into..
2-I am reading 36 volts on both sides of the solenoid (key off), is this normal?
3-When should charger auto turn off?
Installed a Buggies Unlimited charge indicator, put the cart on charge. Happened to stick VOM on & read 40 volts. Didn't think that they should go that high. It is the PowerWise+ charger....
4-anyone had experience with a Curtis 36 to 12 volt inverter, do they have large amp draw when no output is needed?
Thanks ahead of time.....


Welcome to the forum...

1 - One is a resistor and one is a diode and yes they need to be there. The resistor keeps a slight pre-charge to the controller and the diode prevents back feed spikes to the controller. The cart will run without them but it's not recommended. Ask Alltrax and they will tell you to leave them on the solenoid...

2 - No you should only have 36 volts on one side until you press the go pedal. You either have a bad key switch, bad solenoid...

3 - The charger turning off depends on the age of the batteries, and how far they're discharged. Normal charging time can vary from a couple hours to 16 hours...

4 - I can't give you exact numbers on the voltage draw of the voltage reducer. I always use a separate 12 volt battery to power accessories...


New Member
Thanks for the help.
Figured there was some reason the resistor & diode would be there.

Key switch supplies power to the new charge meter so I think it's good, will look into the solenoid being bad.
Was thinking of upgrading to a heavy duty solenoid with the new controller, would that be worthwhile? Any recommendations?



I'd go with a heavy duty solenoid. Seeing how your upgrading the controller and cables you might as well upgrade the solenoid to. Here's a link to the White Rodgers 586 HD 36 volt solenoid. You may be able to find it cheaper if you look around on some other golf cart parts sites...

White Rodgers 36 Volt HD Solenoid


New Member
Took all the wires off the solenoid and tested continuity thru it. Got zero....

There is a large resistor (250 ohm) across the 'main' poles of the solenoid & a smaller diode across the small poles.
Could the large resistor be bad, when I put it back on the solenoid - I get continuity.
(Don't know much about diodes or resistors or how to check if they are good or bad...)

I then hooked up the +side of battery to solenoid & then read 36.4 volts from solenoid output to - side of battery.

I am now thinking that maybe I need to pursue the HD solenoid & the resistor/diodes!

Thanks for the lead on the solenoid!


New Member
Well, I have put in the new Alltrax controller with a new 36 v. White Rodgers HD solenoid, new resistor & diode. Took a little while as I rewired the motor/FR swtch with the -4 guage welding wire also.

Test tonight and cart ran good.
Just for my own edification, I then took the voltage across the new solenoid with the key off. Got 35.4 volts on output of solenoid to the controller....... so I then pulled the key switch & checked it for continuity - it works fine.

There is a blue & green wire to the key switch. The blue wire is hot, traced it back to the FR switch & am now scratching my head.
Where do I find a wiring schematic?

I'm thinking that someone 'in another life', before I got the cart has done something with the small wiring between the pedal and FR switch......

Any help would be appreciated.



Well-Known Member
Charlie, your cart is running correctly. If someone had messed with the control circuits it wouldn't run at all, or it would be toasting microswitches left and right. I'm no factory tech, and my cart is not near me, but I think the results you are asking about are probably normal. Have you tried the E-Z-Go Resources area for a schematic?


New Member
Thanks for the reply Gorno...
No I hadn't found the schematics, thanks for the lead - not very computer literate.

Have printed the Wiring diagram TXT Fleet & the TXT troubleshooting NON PDS so I have something to ponder on.

The reason I believe someone may have fooled with it is the controller that was in it when I got it had a sticker on it from a outfit in Florida. Probably some place my dad took it to have it repaired.
I originally bought the cart from EZGO here in Augusta, had just come off a lease from a golf course in Arizona. Pop had been piddling with a early 80's piece..... SO he really lit up when we gave him this cart.

I don't know how long a controller is supposed to last, I assume it's like a car's ignition coil. Could be tomorrow or 30 years, who knows. But I figured that if the controller always has 36 volts to the B+ terminal, it can't be doing it any good.

New Alltrax + HD coil + resistor&diode + ~$350 soooooo everyone says it's not supposed to have that voltage on the output of the coil so that's why I'm looking for an answer.

By the way, the folks at Mr Golfcart (Waynesboro, Ga.) (where I got the stuff) told me that EZGO told them a couple of years back that it was OK to leave the 250 ohm resistor off.
I'm going with Hotrod & Alltrax advice, it's on there.........


New Member
HRC & Gornoman, I am beginning to believe.......

Went through the wiring diagrams -compared to the cart and it all looks kosher.
Reread the info that Alltrax has on the 'pre-charge' resistor & diode.
The resistor limits the amps but must still allow the 36 volts to the controller, at least that's how I'm trying to understand getting the reading on the solenoid output to the controller.
What is still mystifying me is that nobody else gets 36 volts across the resistor/solenoid?????

Thanks for the help!! (& understanding with a ol' non-electrical type)