[Healeys] compression electrical

[john spaur]

So... I need to do a compression test.
The engine is out of the healey sitting on a dolly. I plan on running 
jumper cables from another car to get the juice to turn the engine 
over. How should I switch the power on and off. I need a momentary 
switch. Can I take the solenoid out of the healey and use it? Are 
there any issues that I should look out for? Does anyone have another idea?

Thank you,
John Spaur
San Jose, CA