"Key on" 12v source
Junior Member
Joined: Jul 2020
Posts: 6
Likes: 1
to the electricians on the forum - where's the best place to tap into a 12v source that comes on with the accessory push of the start button? I'm using a the low amp + for an airlift compressor relay (high amp 12v line will go to battery). Engine compartment fuse box? Passenger well fuse box? Which is a good fuse to use a tap on?
hello guys
looking for a 12v ignition source wire that i can tap into under the hood or close to the passenger side area, i'm fixing to set up my switchpros 9100, and need to tap into a 12v ignition wire thanks!!!!
Flaccid Member
Joined: Sep 2016
Posts: 2,168
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From: Maine
I suppose I could drag some wires from inside the cab, but I'd rather not.
Last edited by DeltaNu1142; Nov 4, 2020 at 12:51 PM.
Senior Member
Joined: Oct 2010
Posts: 2,157
Likes: 518
From: Southwest
If you have a multimeter or a 12v probe with light you can find it yourself. Clip the probe ground onto the ground thats close to the battery. With the ignition off, touch the fuse lead until you find one with no power. Turn the ignition on to confirm accessory power.
Junior Member
Joined: Sep 2022
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Where did you mount the sp9100? I’m trying to figure out where to mount control and switch panel. Not many people showing installs on a f150.
Last edited by Polcat79; Apr 19, 2023 at 09:44 PM. Reason: I replied wrong
Junior Member
Joined: Nov 2020
Posts: 6
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S2kdrifter - separate question - have you found a switched 12v source/fuse in the engine bay fuse box? They all seem to be constantly on. Did not do an exhaustive search, but pulled about 6 fuses that I thought would be switched and they were on with ignition off. Maybe it has to do with the 30 minute power time out?