Battery wiring M1009? blazer

mudmagnet63

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My brother just bought a 1986 blazer the batteries are wired positive to positive Neg to neg which is 12V is the isolated ground on one alternator what makes it 24 v? the starter seems to be dragging which makes it hard to start ( motor spins slowly ) or is the starter in need of replacment ? and if so do we need a 24 v starter.

Mud
 

Westech

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the isolated ground is what makes it 24V.. they should be wired in series if nothing has been changed. Kinda hard to tell whats going on with no pictures. if some hack has been in the wiring and f-ed it all up... good luck. might just want to put full coverage on it and burn it to the ground.
 

Warthog

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My brother just bought a 1986 blazer the batteries are wired positive to positive Neg to neg which is 12V is the isolated ground on one alternator what makes it 24 v? the starter seems to be dragging which makes it hard to start ( motor spins slowly ) or is the starter in need of replacment ? and if so do we need a 24 v starter.

Mud

Welcome to SteelSoldiers.

Is your brothers truck a ex-Military truck or is a cilvilian model. The Civvy units do have two batteries wired parallel. The military units have them wired in series (12v+12v=24v)

If it is a military unit then the first stop for you is the CUCV forum. Read the top post which is the CUCV Wiki

Cucv - Steel Soldiers::Military Vehicles Supersite

Download all the Tech Manuals while you are there.

Second stop is the CUCV FAQ sticky. It has many answers to common isssues.
http://www.steelsoldiers.com/cucv/20600-faq-thread-cucvs.html

Almost every question you will have, has been asked and answered before. It just takes alittle searching (and knowing how to search different ways) to find the asnwer.

Here is the wiring diagram for the CUCV batteries

Right click on the thumbnail and choose "Open Link in New Window"
 

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mudmagnet63

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Thanks for the replies guys. The wiring diagram helped us get the batteries wired right so she fires right up now. Gen #2 light stays on now and #1 comes on then goes off after the motor is idled up ??. I will download the rest of the manuals and read them tonight I think there is more issues with the wiring. aua

It is a M1009 Govt issue blazer
 

Warthog

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Great job of fixing the battery wiring.[thumbzup]

Sounds like its time for an alternator rebuild. But check the belts first.

The Oklahoma Convoy of SteelSoldiers is having a workday next weekend in Tuttle, OK

And on the 15th of May, a group of guys is driving to Kansas for their parade/show and Del City is having their annual Salute to Armed Force Parade.

You are more that welcome to attend.
 
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tim292stro

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Welcome to the SS forums you two!

Sounds like the 12V alt is functioning correctly, but the 24V one is not charging.

First question - are there two alternators? The Roscommon 12V modification often includes pulling the 12-24V (high 12V battery's) alternator, leaving only the GND-12V (low 12V battery's) alternator. That's how my '86 M1009 came from the last owner.

The factory wiring diagram is in section 4 of the xxxxxx-20 Technical Manual. It's all there, and for free. Beats a Chilton's any day :beer:

The Gen2 (12-24V) alternator is triggered from a relay powered by the ignition as well as the 24V voltmeter in the dash. If that circuit has been altered or removed during a 12V conversion, you'll have to repair that to make the 24V portion work correctly. You should also check the wiring to the 24V terminal block on the firewall (passenger side). If it's measuring out at 12V then it's been rewired too.

Pictures help when you can't describe something: nopics
 

Warthog

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