Add Club Car type FNR switch to RXV

[Fairtax4me]

Originally Posted by BobBoyce

The keyswitch is a BCD (Binary Coded Decimal) switch, where combinations of outputs of KSI, Forward, and Reverse are switched in a (break before make) sequence. It's not a simple selector switch. If invalid combinations of the 3 outputs are accidentally selected, as is possible if seperate key and F/R switches are used, you can lock up the controller. The KSI signal must be momentarily interrupted during the switching, which is why On (N) is in the middle. In between each of the 3 on positions (F/N/R), KSI output switches off before re-engaging AFTER the F or R are connected. It is a matter of timing on the 3 controller inputs. Either F or R being selected while KSI is already on is an invalid state. If both F and R get energized at the same time (a make before break switch), you've just created an invalid input state that could lock up and destroy the controller.

You can extend the wires, and risk your controller if you ever get an open connection on a splice. It is best not to mess with that wiring on an RXV. Messing with the wires in the dash has killed more RXVs than any other single action by RXV owners. Well, I guess it could be a tossup... cutting one or both reverse beeper wires, which usually takes out the controller, might actually be more common!

Note to self: say NO to EzGo
Who comes up with that and thinks it's a good idea? That switch fails and your controller fries.

[cgtech]

I have seen corrosion in the harness mess up that circuit (command F and R at the same time) without damage to the controller. Does throw errors in the controller, and prevent vehicle operation, errors went away when the corroded harnesses got replaced

[BobBoyce]

Originally Posted by cgtech

I have seen corrosion in the harness mess up that circuit (command F and R at the same time) without damage to the controller. Does throw errors in the controller, and prevent vehicle operation, errors went away when the corroded harnesses got replaced

I've seen that too, but it's a soft contact through a high impedance path (the corrosion). It'll trip a logic switch and cause errors. A hard contact on both could do more and cause hard damage to a peripheral chip. The results of unpredicted combinations of inputs can have a range of results, from just causing errors and soft shutdowns, to severe conflicts in outputs that are unpredictable. I repaired a new Curtis RXV controller recently that was taken out by the cutting of the reverse beeper wires while the Danaher controller was installed. It took out the Danaher controller, and when the Danaher to Curtis conversion kit was installed, it then took out the Curtis controller. I recognized the pattern of damage in the controller, and asked about the reverse beeper. It had never been mentioned in his thread, as he had thought that washing the RXV had caused the damage. Once he said that he had cut the reverse beeper wires before washing the RXV, it became clear why the damage had occured to both controllers.

I had to remap the Curtis controller inputs/outputs to bypass damage, and shut down the poweron tests related to those circuits. I was able to salvage the new controller, but there is no guarantee on how long it will last. There may have been minor damage to peripheral I/O chips caused by that event, that may cascade to other circuits in those same chips at a later date. Large scale integration reduces circuit board size, but increases how much can be taken out by a failure or partial failure in a single chip.

Bob