1990 Marathon with ScottyB's conversion

[crackers450]

Hi All,
This morning I DROVE the cart into the garage to replace the ignition switch (it didn't happen), to cold so I tried to reverse out NOTHING, battery pack is reading 38.2v.
So testing the cart
connect DVM neg lead to M-
connect DVM pos lead to B+
reading should be 0 zero Volts, my reading is 19.5v (disconnect all 6 pos leads from batteries & I still get 2.5v , connect all back up, push accelerator to make solenoid click, you should read full battery pack 38.2v
my DVM reading is ZERO, controller LED is solid green, then goes out.
Full acceleration DVM reading is ZERO no movement, controller LED is solid green.
the motor has been tested with a 12v battery & is OK.
I have replaced the solenoid and diode with a new one
I have replaced the POT & microswitch with a new one, POT lead reading is 0 to 5.0 ohms
replaced both F&R wiring from rocker switch F&R with a slightly longer leads
the cart moves intermittently, yesterday I used it all day, today moved it into garage but had to push it back out
what do I check next please
Laurie