Nominal voltage leaking through MOSFET

[Bunnykiller]

have you considered an IGBT? no leakage...

 

[kartoffelfaust]

There has to be a short or short to ground somewhere. Check all source and negative wiring. Are the mosfets heating up?

 

[kartoffelfaust]

Also interesting that it's leaking the same voltage you wish to apply to lighted switch.

 

[Steveinherts]

Ibgt? What's one of those? Checked the entire circuit for continuity on both where there should be AND where there should NOT be any, everything check out, can find no prob, have put the old fet back in so only a very small v leak, funny thing is this am I put an atty on and guess what - the volt dropped to zero, have taken a batt reading and will check tonight if it's draining the single batt I have in, if it doesn't, is the atty trying to pull current without the fire switch and shutting the fet down. Other than that my multi meter was loading slightly, just like ive been told by you good people, let's hope so I can glue this sucker up and use it. almost forgot the fet is stone cold.

 

[Bunnykiller]

that makes perfect sense now... the circuit needs to be complete, load in place.... I thought you were getting voltage with atty in place... ( taking reading from internal sources... all is good

 

[Steveinherts]

Yep, all good, 48hr with atty in place, no power loss from batts.
It has been an education in fets, didn't realise an open circuit would give an anomaly, at least I can rest easy knowing I'm not putting 80+ amps of death in my mouth!
De-solder, glue & finish off, then project done.
Where should I post the pics, here, a new thread or somewhere else?

Next project ideas - battery less mod, butane powered maybe, I could turn myself into a human torch!
Thanks again everybody.
Steve