That trick with the 12-gauge jumper wire on the door lock circuit backfired on me yesterday.

I tried it on a 90s Dover in a Cincinnati office building and it tripped the machine room breaker, which taught me that old solid-state controllers really don't like that kind of shortcut, so what's the proper way to safely bypass for testing on those older units?

2 comments

2 Comments

the_wendy9h ago

Use a test cord with a fuse in line.

rubyg518h ago

Yeah, a fused test cord is the only way. Fried a board on a mid-80s Montgomery last year doing the same dumb thing. That quick zap can cook the driver chips. Now I keep a 1-amp fuse in my kit just for that.