KX36-3 Ignition power loss

[TnT woodworks]

Hi all,
I recently fitted a new ignition switch and main isolator on the KX36-3 and used the machine with no issues, I stopped and started it all day with no problems.
However, I came to use the KX a few days ago, switched the Isolator on and the Ignition and the lights came on, it also showed full voltage of around 15volts on the battery readout.
When I next turn the key to warm the heater plugs, the heater plug light doesn't light up, then if I turn the key to start the engine all power is lost to everything including the battery readout going to zero. Let go of the key and it all comes back.
On a side note, the engine doesn't start either.

I have a Denso relay (maybe a relay) which I believe to be the problem. It has hard-to-read product numbers 166700-2173 or 2172 or 2178.
I've tried to source these but to no avail.

Can anyone shed light on to my issue?

TIA
Rob H

 

[GreensvilleJay]

Did you use the OLD battery cables ?
if so how old are they ? ANY signs of corroision ?
'total loss of all power' can indicate a cable(s) cannot allow CURRENT through.

 

[TnT woodworks]

Did you use the OLD battery cables ?
if so how old are they ? ANY signs of corroision ?
'total loss of all power' can indicate a cable(s) cannot allow CURRENT through.

Cables are fine, it only loses power when the key is turned fully to the start position.

 

[GreensvilleJay]

'good looking cables will easily pass an amp or two for dash lights, fail when asked to carry 100s of amps when trying to spin starter.
You'll get similar result with bad connections, especially those 'clamp on' battery terminals.

 

[TnT woodworks]

'good looking cables will easily pass an amp or two for dash lights, fail when asked to carry 100s of amps when trying to spin starter.
You'll get similar result with bad connections, especially those 'clamp on' battery terminals.

I Will look a little deeper and supply feedback.