Non starter after removing engine Options

[llamatronica]

Hi all, recently bought myself an st202 after having a zzt230 for a few years and not really liking it, bought it cheap as it required a new clutch and cambelt, ran fine on 100mile drive home, so pulled the engine and gearbox and completed the work required, put it all back together and it seems to have an strange fault that I've never seen before(been rebuilding engines for 20years), to begin with it just wouldn't start, then after checking all sensor and vacuum connectors it did start, and ran fine, so switched it off to finish the installation and when I tried starting it again I got this,
Key to on and the temp gauge goes to max and no engine light, won't start, turn key to off and engine light comes on temp gauge goes to min and fans start, turn key to on and same but when key is turned to off all lights and fan are off, tried shorting pins te1 and e1, but there's no engine light to read when ignition is in on position
everything is plugged in and connected as should be, tried bypassing circuit opening relay with no joy,

[llamatronica]

Been out this morning and checked coil and voltage to and checked for breaks in wiring loom, all fine, plugged all back together and started first time, idled up to operating temp, switched off, and began doing same as before, checked all sensors and all within spec

[Smaay]

sounds like you have a short somewhere in the wiring and after running it gets shorted. however you havent mentioned any any blown fuses so its not a power short, maybe a signal short.

[llamatronica]

Have looked at a lot of the loom with no real signs of damage, have narrowed it down to the efi relay staying on after the key is off after the key being switched to on, remove the efi fuse the relay clicks off and the engine light goes off and the temp gauge returns to zero, just had the relay out again and tested it for operation under load and works fine

[Bitter]

Missed a ground?