copper studs for FNR switch

[dvmartin]

Yes, I would be interested in the thicker busses. Let me know how they work out.

[rib33024]

See if this helps any---

older EZGO

Thanks to---- pggroves--

Originally Posted by pggroves

MECHANICAL FNR HEAVY DUTY BUSS UPGRADE

OK, had a bit of a problem with the SD card out of the camera so I lost all but a couple of the pics of this rebuild. So, I had to “rebuild the rebuild” and get the relevant pictures for this post.

This upgrade will increase the amp carrying capacity of a mechanical FNR switch on an EZGO golf cart.

To fab your own buss bars, obtain enough alloy 110 or 102 1/8"(.125”) thick copper sheet to make 2 each buss bars ½” wide by 2-1/4” in length. Use the factory buss bars as a template to drill 2 holes @ 21/64” diameter for the studs. File or grind the corners round.

Now, armed with your new buss bars, follow the directions below to install heavy duty buss bars in the FNR cam.

1. Disconnect main positive and negative cables from battery pack then insulate and secure.
2. Remove FNR switch cables and micro wires then mark, insulate, and secure.
3. Remove FNR switch from cart.

Now that the FNR switch is out of the cart and on the bench you should have something that looks like this.

Remove the lock nut from the back side of the FNR switch shaft. Indicated by the arrow in this pic.

Pull the cam and shaft assembly from the shifter side straight out from the FNR switch board. You don't necessarily have to remove the reverse buzzer or micro switches. If you don't remove the micros, make sure to align the indents in the cam to the micro switch rollers and don't bend them when reinstalling the cam on the board.

You should have something that resembles this pic. The shaft has been removed for clarity. You can see it behind the cam.

IMPORTANT: Note the orientation of the buss bars on the FNR cam. Then remove the 4 nuts that retain the copper studs, springs, and bushings. You should now have this in front of you on the bench.

Remove and replace as required the 4 copper studs. If you get this far, you should replace all 8 studs as a rule anyway. Inspect the springs and measure length of each. If all measure close to same then you should be good to go. I have yet to find HD springs for this application. I'm still looking! You may have to trim the bushing length to insure proper fit on the FNR cam. I cut 1/16" off of each bushing to accommodate the thicker buss bars. If you trim the bushings, make sure to cut squarely!!! This pic is of the FNR cam completely disassembled. The arrows point to the buss bars. That's what we're after.

Here is a pic of your new HD buss bars compared to the factory bars. Now you see why upgrading the buss bars is important!

Reassembly is reverse. Make sure to put the buss bars back in the correct orientation on the cam as noted above. Do not tension the springs until all nuts are started then tension (tighten) the nuts sequentially in a cross pattern.

THIS PART IS VERY IMPORTANT. REFER TO THE PICTURE BELOW AND MAKE ABSOLUTELY CERTAIN THAT THE LONG EDGE OF THE COPPER STUDS ARE ORIENTED EXACTLY AS THIS PHOTO. THIS INSURES PERFECT CONTACT WITH THE OPPOSING STUD WHEN YOU REASSEMBLE THE FNR.

This pic shows why aligning the studs on the FNR cam is critical. The first pic, the FNR is in Neutral. The second pic the FNR is in forward. If you don't align the cam studs properly then you will not make perfect contact with the mating stud resulting in problems.

Reinstall the cam back in the FNR board. I use a very small amount of dielectric grease on the shaft but only where it passes through the phenolic board. Install the shaft nut and washer and tighten. You'll have to decide how tight you want the FNR lever to be. You'll know if you over tighten the FNR shaft nut since you won't be able to turn the FNR lever.

As a rule, I strip the FNR completely and clean and polish every part. I normally replace all 8 copper studs and suggest you do the same.

Congratulations! You now have a heavy duty FNR switch!

Tools list:
Screwdriver (phillips & straight)
Wrenches (3/8; 7/16";1/2";9/16")