Resistor cart wiper arcing - symptom or cause?

rlw

Hey all,

It's been quite a while since I posted here. My '84 Marathon resistor cart's been running fine up 'til just recently.

The last few days, I've noticed that the cart will sometimes not respond to a press on the accelerator pedal, then lurch forward (or backwards, if it's in reverse) before it gets going. I could hear the solenoid engage, so I began to suspect the wiper board.

This morning, when I got in it, it wouldn't move at all. I moved the FNR switch to reverse, nothing, forward, nothing, then kicked the accelerator and it stuck down (cart STILL not moving) and began arcing to beat the band. I turned off the key, popped the seat and got a face full of acrid smoke. Then, I kicked the accelerator a couple more times, turned the key on, and managed to drive it up the driveway and put it in the garage.

This evening, I yanked the two batteries either side of the wiper and took out the wiper board.

The "high speed" contact (the one that skips the resistor altogether) was surrounded by carbon and little globs of melted copper. The wiper contact (the part that moves) was pitted badly. The other 4 contacts look pretty good. Incidentally, the bottom contact is not connected to anything, it's just a place for the wiper to rest when the cart's not moving (see photo 1).

The high speed contact goes directly to the motor's "A1" connection. I took a look at that, and it looks like it's kind of corroded (see photo 2).

My question? Is the arcing on the wiper board the CAUSE of my problem, or is it a SYMPTOM of a bigger problem, maybe with the motor or just a bad connection ON the motor? I also haven't inspected the resistor itself - could a "shorted" resistor cause this? I don't really think so, since a "shorted" resistor (a couple of the coils compressed and touching) would just make the cart run faster in "3rd gear" - you're effectively shorting the resistor when you mash the pedal to the floor anyway.

I'm going to disassemble the wiper and move the bottom "resting" contact up to where the "#4 high speed" contact goes. I'll also take the wiper contact to a buddy of mine's machine shop and get him to cut off the bad part and square it up. I'll grind down the "bad" contact formerly known as the "#4 high speed" contact and use it for the disconnected "resting" contact.

I'm also going to disassemble the "A1" connection, clean it up, put some DE-OXY on it, and put it back together.

Any suggestions on what else I should try before I reassemble it and fire the thing back up?

Thanks,

RLW

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BGW

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yurtle

It's 30 years old, so whatever the cause, it's prolly time to replace. The FNR and wiper board are high current switches, with the wiper board getting more "action", so it's more likely to suffer wear. If you think you can repair it, the only real risk are your cables, which are probably due for repair/replacement anyway, if they're original.

rlw

Yurtle,

I made the cables a couple of years ago, 4 gauge. FNR switch seems fine. Thanks for the response.

RLW

scottyb

I have seen worse. You can restore this assembly with a flat sanding block . You may need to remove some splattered material to get the proper separation between buttons again. Clean and mill the wiper contact and stretch the contact spring some to restore contact pressure. It won't be new but it will work for a while. Eventually you will be back at this condition again = it's the nature of the beast.
You can stop this dangerous sticky pitted contact syndrome with a solid state speed control conversion from Carts Unlimited.

rib33024

Check the resistor coils and make sure none of them are broken that will cause the wiper arcing

rlw

RIB,

I'll check the resistor. Hadn't thought about a break being the cause.

ScottyB,

I'd *LOVE* to make this into a controller cart some day, just can't justify spending more on the controller kit than I did buying the cart! ;^) As to your suggestion about milling the wiper contact and stretching the spring, that was pretty much what I had in mind. Is there any source for a replacement contact with the cable (4 gauge)? That is really the weak link in the wiring chain -- I made up 4 gauge cables a couple of years ago, and the highly flexible cable on the contact is the only 6 gauge left in the cart.

Regarding resistor carts vs. controller carts, I really like the simplicity of a resistor cart. I know all the arguments of why a controller base setup is better, but you can't fix a busted controller with a set of wrenches and screwdrivers!

A controller is a potted black box full of electronics, and when it breaks, you pretty much have to get a new one.

I use the cart to run around my 6 acres and my neighbor's 55 acres. I built a hillbilly dump bed with stuff I had laying around, and a back seat (again, with stuff I had laying around). I doubt if I ever put more than 4 or 5 miles max on it between charges.

I'm thinking of nominating my cart as "Ugliest Hillbilly Technology Cart" - might be a new thread worth starting ;^)

Thanks to both of you for the input.

RLW

rib33024

if you keep it old school you will need the following


https://www.eastcoastcarts.com/catal...12&pNoFilter=1



EZGO 1971-81 Foot Switch Board With Contacts


http://www.golfcartking.com/EZGO-Foo...acts-p/728.htm




EZGO 1965-81 Foot Switch Wiper Contact

http://www.golfcartking.com/EZGO-Foo...tact-p/703.htm




EZGO 1970-85 Complete Resistor Coil Assembly

http://www.golfcartking.com/EZGO-Com...bly-p/2698.htm



also replacing the following

EZGO Solenoid Coil 36 Volt 1968-up

http://www.golfcartking.com/EZGO-Sol...olt-p/1106.htm




Micro Switch 3 Terminal EZGO Electric 1971-1981

http://www.golfcartking.com/Micro-Sw...tric-p/794.htm

replace all cables

quote CTD

rlw

Rib,

Thanks for the links. The solenoid was replaced with a new one when I made up the 4 gauge cables. I tore down and rebuilt the resistor at the same time. I might go for the wiper board and contacts.

Is there any source for the individual copper bolt contacts on the wiper board?

RLW

rib33024

Resistor cart parts


https://www.eastcoastcarts.com/catal...12&pNoFilter=1

coosa

Why don't you look in the classified section for a post I made about a month ago that has all the stuff in the pic above? I took my 84 out of commission a few months ago because of the frame rusting in two, and offered all the working parts dirt cheap. No takers; I thought I was the last one running a resistor cart.

Its easy to just change the one bad contact if you have extras, and I accumulated all sorts of extra stuff over the 16 years I ran mine. I would suspect the problem is the contact or the wiper; they just wear out and have to be replaced. I would have liked to have fixed mine, but it was just too far gone. There are advantages to running a resistor cart, though after running a newer one, I'd have to say that I much prefer it.

Good luck with it!