@Paulatics, thank you for speaking up to oppose Bill C-5!

I called 3 other senators yesterday about Bill C-5, using a script from For Our Kids.

EDITED to remove a call to action after learning from @stephanie it's too late to stop this legislation in the senate.

@nottinghack And that's the cleaning DONE!

Just have electrics/electronics to test and all being well, I should make a start on reassembly.

@nottinghack Update:

Who knew that cleaning 40 years worth of grime would be really hard?

Yesterday I was able to get everything stripped down, and briefly checked, mechanically it seems sound apart from the chain, which was rather slack despite ample pressure from the tensioner and also a few of the links were seized, I was able to free all bar one of these so it 100% needs a new chain.

Also the weird cone nut tool, perfect bottle opener.

The actual cleaning is a long and slow process, I'd say overall I'm probably only 20% of the way there, as I have read in various places Cif cream does work best but wow does it take a while to scrub in, also using green scowling pads leaves behind a green tint in the white plastic which was fun to then scrub out, it looks more like this is going to be a multi day cleaning job before I actually get it reassembled again; well, now back to work

@nottinghack And the C5 springs into life for the first time in over 3 decades!

The POD once again showing minimal load as the wheels are off the ground this is all great!

Just now need to tidy up the wiring and get this thing out for a ride.

@nottinghack I was a little concerned; after a few minutes the POD LEDs for battery status would loose an LED, but after soak testing for half an hour it just remained at that, I realise I had the PSU set exactly for 12v, and the battery I have measures at more 12.5v, so in theory if there were losses the POD could be seeing 11.5v and assume declining battery, setting the PSU for 12.5v and I never lost an LED - the POD and ULA appear to be working perfectly!

I then disassembled the test setup; and started putting the control box back together; this was a little awkward, the plastic case had been welded together and I had to cut these welds, but there were tabs for 3mm self tapping screws, I which I was able to fit some black plastic 3mm screws and nuts in to keep it together and also it kinda looked the part.

Quickly attaching all the wiring in the C5 and remounting the control box, I was ready to give it a test with the real motor.

@nottinghack After making these repairs, I wanted to test absolutely everything to be sure nothing else is about to blow.

I initially started simple, I connected the control box to a power supply, current draw was small and all the voltage lines looked OK.

Moving a little further, I wanted to make sure it could switch a load without issue, but I didn't want to do that with the POD attached in case of damage to that; looking at the circuit diagram for the control box, transistor 3 appears to connect from the coil of the power relay at the collector, and 0 volts at the emitter, with the base coming from the pod from a line named "RELAY DRIVE", so this must be how the pod can disable the motor.

A simple dupont wire between pins 1 (+5Va) and 7 (relay drive) on header X9 (POD connector) ensured the relay was always enabled, also shorting pins 4 and 5 on X6 (thermal cutout switch), then just adding a small 12v motor to the motor terminals, and shorting pins 5 and 6 (motor switch feed/return) on connector X8 resulted in the relay making a nice clear click and current draw at around half an amp - perfectly fine.

Then I just quickly popped the POD off and with some dupont wires connected it to the control box, with a 10k ohm resistor between pins 1 and 2 of X6 to simulate the thermocouple in a good state, and everything worked as expected, the POD LEDs behaved just as expected, showing full battery and low load.