I'm looking at picking up an 85 K5 Military Blazer. Has anybody done any install work on them? If so do you have any pictures? Anything special I should know about them beside make sure I have 12 volt lines and not 24 volt?
Thanks
Ben
Military Blazer install questions?
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Military Blazers were NOT 12V positive ground. If it were 12V/pos, somebody made it that way. They were all 24 volt negative ground ON CRANK ONLY and 12V neg. ground at all other times. There are two batteries and two alternators. The batteries temporarily connect in series during engine starting and once the key is released, they are paralleled again. Two alternators are needed and must ba maintained on this system. You need isolation to provent equipment damage (which is easy to do on these trucks)Now here's the trick....
You need to get 12 volts from the FRONT battery's positive. Remove the front's positive cable, cut it's terminal off and crimp/solder on a 3/8" copper terminal. Mount a 3/'8" insulated stud somewhere that this cable will reach. Fabricate a new cable from the same gauge and install a 3/8" ring and also connect to the stud. Run this cable to the location where the front battery's positive cable ran to. You are just installing a junction stud in-line of the front batt's positive cable. Now....
Get a continuous-duty solenoid rated for your load+25% and install near the stud block. Connect the proper cable to the stud and the other end to the solenoid's one big terminal. The other mating terminal will be your power feed going into your master fuse/breaker for the equipment.
Ground one of the solenoid's coil leads to chassis. Run a #16 from the other into the passenger compartment to the fusebox area. Once there, install a 10A inline fuse and connect to a soource in the fusebox THAT IS HOT ONLY WHEN THE KEY IS IN THE RUN POSISION!!!!! MAKE SURE THIS CONNECT P(OINT IS N-O-T HOT DURING ENGINE CRANK!!!!
The purpose of this is to ensure that 24V does not get into your equipment during series crank mode. I had to replace a Maratrac that was damaged from somebody that ran it to the incorrect point and doubled the voltage to the radio.
You could technically do this without the solenoid, but these charging systems do wierd things for some reason. The 24V system was put in place to operate the military 24/28V radios and on SOME Blazers, the glow plugs.
I've done a dozen of these trucks and have had no problems with equipment in them.
You may also want to disconnect the switches to the left of the steering column that engage 'blackout mode' lighting in the bumpers. If you are driving at night and bump one of these, you lose exterior lighting and that, of course, might be bad!
You need to get 12 volts from the FRONT battery's positive. Remove the front's positive cable, cut it's terminal off and crimp/solder on a 3/8" copper terminal. Mount a 3/'8" insulated stud somewhere that this cable will reach. Fabricate a new cable from the same gauge and install a 3/8" ring and also connect to the stud. Run this cable to the location where the front battery's positive cable ran to. You are just installing a junction stud in-line of the front batt's positive cable. Now....
Get a continuous-duty solenoid rated for your load+25% and install near the stud block. Connect the proper cable to the stud and the other end to the solenoid's one big terminal. The other mating terminal will be your power feed going into your master fuse/breaker for the equipment.
Ground one of the solenoid's coil leads to chassis. Run a #16 from the other into the passenger compartment to the fusebox area. Once there, install a 10A inline fuse and connect to a soource in the fusebox THAT IS HOT ONLY WHEN THE KEY IS IN THE RUN POSISION!!!!! MAKE SURE THIS CONNECT P(OINT IS N-O-T HOT DURING ENGINE CRANK!!!!
The purpose of this is to ensure that 24V does not get into your equipment during series crank mode. I had to replace a Maratrac that was damaged from somebody that ran it to the incorrect point and doubled the voltage to the radio.
You could technically do this without the solenoid, but these charging systems do wierd things for some reason. The 24V system was put in place to operate the military 24/28V radios and on SOME Blazers, the glow plugs.
I've done a dozen of these trucks and have had no problems with equipment in them.
You may also want to disconnect the switches to the left of the steering column that engage 'blackout mode' lighting in the bumpers. If you are driving at night and bump one of these, you lose exterior lighting and that, of course, might be bad!
I would love to see the pictures of the truck. If you don't want to post them you can email them to me at [email protected].
Thanks again for the help.
Ben
Thanks again for the help.
Ben