84 Blazer Diesel M1009 24v or 12v System?

[CaptFlyboy]

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.

Hi.. Newbie + not too mechanical. I looked at the M1009 battery wiring diagram so I know my two batteries are wired in parallel but not sure if they are wired correctly since it's always a bear to start when it gets cold <20. I know this is pretty common for diesels but it just seems the battery is draining too fast. Even with the truck plugged in I get maybe two or three tries before I need to charge the battery.

I only see one alternator so it makes me think it was modified at some time. I've read if you have two batteries system that the weaker battery will drain the stronger battery to the weaker battery level so this might be why I'm not getting much cranking time.

So from the pictures can you tell if this truck has been modified to start with a 12v starter?
If it was wired wrong would it even turn over a 24v starter since it is wired in parallel so only putting out 12v?

If it only needs 12v to start then could I just disconnect the second battery & use it to jump start the primary battery when I need it jumped?

I could put a trickle charge on the 2nd battery when it's not being driven to keep it topped off.
I have this one on order from amazon which will work with either 12 or 24V systems...
NOCO Genius G7200 12V/24V 7.2 Amp Smart Battery Charger and Maintainer


Thanks for your help!
CaptFlyboy

 

[Warthog]

Welcome to the site.

Moved you question to its own thread.

Before starting any electrical troubleshooting you should make sure your batteries are up to snuff. That includes a full charge and load testing. You can do that yourself or have a parts store do it for you. Looking at your battery pictures yours look to be on their last leg.

From the pictures your truck does seem to have been converted to 12v. The passenger side alternator is missing and the leads have been taped up.

Because of the design of the diesel engines, (high compression) they do like to have "extra" help from the second battery. While one many crank it over, it will not last long.

How long have you had the truck? The wiring sure look "creative". Not much is stock on the battery side.

Is the relay on the passenger fender for the starter?

As far as the starter, a 24v version will crank with 12v but not very well. Just as a 12v version will crank with 24v but it will not live long.

 

[CaptFlyboy]

Creative Wiring..

Welcome to the site.

Moved you question to its own thread.

Before starting any electrical troubleshooting you should make sure your batteries are up to snuff. That includes a full charge and load testing. You can do that yourself or have a parts store do it for you. Looking at your battery pictures yours look to be on their last leg.

From the pictures your truck does seem to have been converted to 12v. The passenger side alternator is missing and the leads have been taped up.

Because of the design of the diesel engines, (high compression) they do like to have "extra" help from the second battery. While one many crank it over, it will not last long.

How long have you had the truck? The wiring sure look "creative". Not much is stock on the battery side.

As far as the starter, a 24v version will crank with 12v but not very well. Just as a 12v version will crank with 24v but it will not live long.

Thanks for the quick reply back... love your handle... use to fly a "Warthog" A-10 hog driver in the AF.
The history of the truck I thought it was military surplus bought by an airport to plow their runway then sold to a guy who used it in my hometown to plow roads. I have a very steep driveway & so I hired him to plow my road which did great since it has the diesel engine & power to move a lot of snow. I bought it last year from him when he decided to sell it. This year I replace all the rusted front fenders & doors & next year replacing the rear fenders + I will have the floor boards replaced so I don't end up falling through someday.

The body shop had to rewire the batteries since they were just hanging by a wire due to the inner fenders rusted away. So I was concerned that they might have wired it wrong but sounds like it's probably right. I've had all the glow plugs replaced last year but still had starting issues with the battery going dead too fast. The Chevy dealer that did the work on it didn't think I needed new batteries yet but I will replace them next if the trickle charger doesn't seen to help. Next time I take it in I'll ask them to verify it has a 12v starter in it.

So you think it would do any harm to disconnect the other battery for now to see how it works on one fully charged battery?

Here is a B4 pic... I'll hold off with an after until next spring when it's finish.