F&R Switch meltdown

[Esteban_Escobar]

I have a '92 EZGO Marathon that I rebuilt and converted from 36V to 48V.
I added to more 6V batteries and upgraded everything under the seat:
- new D&D 170-012-0002 motor
- Alltrax 48500 controller and 500 amp solenoid.
- Heavy duty F&R switch

Yesterday as I was driving along with 3 other people in the cart, it suddenly lost power and started slowing down. I stopped, lifted the seat and saw that my F&R switch was smoking and for a brief second there was a fire. I turned the cart off, pulled out the key and blew out the fire. We had to push it the rest of the way home.

So, my question for the group here is, what the hell happened? This cart has been running like a top since I rebuilt everything last October. The only thing that I know for sure that made today any different from any other day I've driven it over the last 8 months is the fact that it was almost 100 degrees out.

I'm now shopping for a new F&R switch, and I'm now seeing not only "heavy duty" switches, but also "Heavy duty, high amperage" switches. I don't remember seeing that distinction when I bought it last year.

I would be very thankful for any advice.

[acguy_409]

Loose terminal caused resistance, heat, overheat, meltdown, shutdown, fun meter dropped to zero, all in that order. Pay particular attention to the washer stacks and torque on those COPPER studs. The first set of nuts are torqued to lock the stud in the wafer. The wires are applied, then, flat, lock washers in that order, then nuts. If there is any preload or "pulling" on your cables, they may loosen occasionally. It is a good practice to check this set of contacts periodically for heat buildup, which is a sure sign of trouble ahead.

[kernal]

Reversing contactor. Eliminates the mechanical directional switch and its problems in favor of electronic switching with a rocker switch like sepex carts.
Here is a kit from a site sponsor: https://www.cartsunlimited.net/rever...ontactors.html Think you can also get these from PlumQuick or others and I think wiring diagrams are available of you want to buy the parts and make your own.

[Esteban_Escobar]

Originally Posted by kernal

Reversing contactor. Eliminates the mechanical directional switch and its problems in favor of electronic switching with a rocker switch like sepex carts.
Here is a kit from a site sponsor: https://www.cartsunlimited.net/rever...ontactors.html Think you can also get these from PlumQuick or others and I think wiring diagrams are available of you want to buy the parts and make your own.

Thanks, I found another thread that discussed reversing contactors but it was old and all the links were dead. I think this is exactly what I need.

[acguy_409]

You can buy the Forward Reverse Wafer and Lugs only if you don't mind a little dissassembly/reassembly. It is 38.99 on Amazon (Performance-Plus-Carts-Forward-Assembly) in lieu of a $100 complete switch assembly. You have to pull the shaft, and separate the lug portion from the frame. I did mine that way, and while I had it apart, cleaned up the inner contacts with some abrasive. The micro switch hardware was a little bit of a task, but just take a digital pic or two of everything before you take it apart, and it will be a breeze. Worked perfectly afterwards.

[scottyb]

I googled Forward Reverse Wafer and came up empty? This being an Ezgo I think you mean the housing that holds the contacts. Typically in these failures the lugs get hot and sink into the housing plastic

[DaveTM]

Yup....get the reversing contactors from ScottyB. I did that and have never looked back. The factory F\R switch is the weakest link in the entire electrical system....well that and factory cables.

I bought mine 100 years ago and they still work fine!!