12v switched & 12v battery hook up on 5.3 harness?
02-06-2010, 12:27 PM
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12v switched & 12v battery hook up on 5.3 harness? i think i have them hooked up wrong. i put a 12v wire from my battery to the fuse box. it will crank up and run, but wont shut off. am i supposed to cut into the pcm #19& #20 wires and hook them up with 12v switched and batt power? if i do that, will power still go to the fuse box?
02-06-2010, 01:35 PM
#2
Im going to assume this is in your 85 which would be carbed originally
That means you would have to add a fuse block of some sort to run the engine functions. In this fuseblock you need a relay specifically for switched 12v (IGN). This should power your main gang of fuses that require 12v IGN, such as PCM B19, Inj, coils, MAF, O2s, trans etc. The majority of your fuses require switched 12v or it wont shut off, and will constantly drain your battery
12v constant is restricted to fuel pump and PCM B20 and B57. These are generally a shared fuse and ran directly to the battery or through a redundant relay for additional protection
That means you would have to add a fuse block of some sort to run the engine functions. In this fuseblock you need a relay specifically for switched 12v (IGN). This should power your main gang of fuses that require 12v IGN, such as PCM B19, Inj, coils, MAF, O2s, trans etc. The majority of your fuses require switched 12v or it wont shut off, and will constantly drain your battery
12v constant is restricted to fuel pump and PCM B20 and B57. These are generally a shared fuse and ran directly to the battery or through a redundant relay for additional protection
02-06-2010, 02:47 PM
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the 5.3 harness has a fuse box built into it. the truck would have been running already without the relays in the fuseblock being powered up. my question is where do i introduce power? through the pcm or somewhere on the fusebox!
