Convert to 12V?

[idM1028]

I already know what the responses are going to be but, here's my situation: Despite all my replacing, swapping, checking, cleaning, fiddling, rechecking and anything else I can possibly think of, I can't seem to get GEN1 to want charge. You name it, I've done it: Replaced the alternator (twice), cleaned the contacts under the hood, switched ground positions, checked voltage in various different places, swapped batteries around, checked batteries, charged batteries, made sure contacts were tight, replaced the fuse, checked for shorts, etc, etc. The thing just doesn't seem like it wants to charge. I'm about at the end of my rope with it (and by proxy, the truck in general) Don't get me wrong though, the rest of the truck is great. Today (after some heckling about a lack of AC on the truck by my father) I got to thinking about the best way run AC on the truck. I realized if I could free up one of the alternator brackets, that would be the best place for an AC condenser. I looked up the instructions for the Roscommon 12V conversion and realized the conversion calls for retaining the GEN2 circuit (which has been working great and I have had no issues with) It occurred to me that if I converted the truck over to 12V I could get rid of GEN1 (and save myself a lot of time, money and hassle), fab together an AC system to fit into the old GEN1 bracket and if I played my cards right with the wire and tubing routing, I could still have room for a turbo if I decided to add one on at a later date. To do or not to do. . . ?

 

[Cucvnut]

did you try running new wires ?

 

[idM1028]

Not yet. davidkroberts is saying its a bad connection. I'll have to double check. I've already cleaned all the contacts. Might have to start replacing them. Honestly, the thought of completely redoing the WHOLE d*** electrical system with new wires has crossed my mind. I know some of the wires would be a pain though. I had to patch up the red feed wire to the fusebox after it completely melted (so much for the fusible link) I would've replaced the entire wire except the other end was glued into the fuse box. Not sure how to get that out. Guess thats what you get when the PO is too lazy to put a fuse into the circuit for the cigarette lighter (I took care of that for him after I fixed the damage) I've also thought of completely yanking the diagnostic port and all associated wires since its just more stuff to get in my way when I'm tracing wires and in my mind its about as useless as, well you know.

 

[dstang97]

Ewwww 12 volt

 

[tnttnt187]

While I'm old school about keeping things the way they were manufactured ie: value,and historical integrity. You bought and paid for it, do what you want. That being said my personal opinion is I would not change the system.

 

[Warthog]

I'm going to send you some info in a PM. We will see if we can troubleshoot your GEN1 problem.

If it works you can post your results.

Warthog

 

[readyman]

idM1028,
In my recent M1009 the military installed AC for ambulance use as you described, nice.
Then the previous owner did the 12V conversion and it's simplified things electric.

 

[Midnight Rider]

I voted no, but in the end it's your truck so do what you want or feel is necessary.

Did you replace the bulb for the Gen 1 light in the dash? Isn't it part of charging system?

 

[idM1028]

I voted no, but in the end it's your truck so do what you want or feel is necessary.

Did you replace the bulb for the Gen 1 light in the dash? Isn't it part of charging system?

It is part of the charging system. It also comes on when I start the truck up and goes out as it should (which means its working) But. . . it also starts flickering or even glows cherry red at high RPM's (usually around 45,50,55 MPH, but also sometimes just before the truck shifts into 3rd) The other thing I don't like about the GEN1 light being part of the charging circuit is its fused into the same fuse for the heater motor. So, if the heater motor shorts out and blows the fuse, guess what. . .

 

[Screamin' Metal]

Okokokok.....I'm gonna give you the lowdown on this!!!!!
If your a millionaire and have military connections, keep her 24V's......I love those systems! I can rebuild them with my eyes closed! You can jump start your truck off of a 12v system if needed, IF YOU KNOW HOW!
These trucks are 20+ years old! They got rid of them for a reason! They knew the parts stockpiles were starting to deplete. They ordered these things with so muck bulk parts to go along with them! IF you have access to the parts, go for it, keep it 24.
IF YOU DON'T, change it over to 12.....alot simplier, easier, and CHEAPER! OVER THE COUNTER PARTS HERE FOLKS! They made a civy unit, twin batterys, 12 V starter....works for years, no problem. The parts are starting to be hard to come by now, and will get harder as we use them up.......
12 volt sys. is only a matter of time.....besides these trucks are not true 24 volt electricial systems, they are a variation. Read up on it and learn.

 

[OL AG '89]

Screamin,
Love the passion, but have to disagree. Don't FIX what ain't broke. As you say "Read up on it and learn it". If you do that, then the 24 volt system will not confuse you and will be easy enough to work on. As far as parts sources drying up, Yes eventually, but not for a while. The base K5 is this truck. It's been "Modified for use" by the Military, but still the basic vehicle that was built for civvy use. I don't like the 24 volt system, but now that I have relearned it (was a 63Y/N while in) & worked on it for awhile, it's growing on me again. I also can hook up the STE/ICE to the truck and play "real" mechanic..... I have stockpiled some of the 24 vlt starters, but they are available from different sources for different applications at this time, so I am premature.
IT's also MUCH easier to troubleshoot a PURE system than one converted to 12, unless you make your own schematics for all the changes you make.
just my 2 cents

 

[Wolf.Dose]

I use in my M715 a DD 6.2 l Diesel and the M1009 electric system for 24 V. If you understand the system, it is very smart and well designed. It gives you any oportunity to ad a sub 12 V system in your vehicle without any problems. Ad a second battery for that and get it charged from G1 with s special relay (look in the motor home scene to find the propper relay). This works great for me since 9 years.
Wolf

 

[boomer431]

My daily driver is a 12v conversion that I have had about 3 years and no problems. It was done before I bought it. The ones I restore I like to keep 24v. Unless I had major problems I would stay with the original system.

 

[southdave]

I have both 1028 is 12v and the 1009 is 24v

 

[trukhead]

Hmm good question....

I have a M1008 that the county converted to 12 volt in the typical splice and crimp method. I am changing the cab and box (matching desert tan) and rust free. So after looking at the schematic I'm gonna finish the job. I'm going to remove all the cabling and wiring aft of the firewall in the charging-circuit going to the respective batteries and alternators. I am going to get a weld on bracket and use a dual pulley 10si one wire self exciting alternator on the driver side to use the dual pulley set up. A positive wire to the battery from the alternator, a positive wire from the battery to the starter, a positive from the battery to the vehicle feed and to a huge fuse and to the glow plug circuit. S%^T&$n the alternator lights in the dash, install a 12 volt meter. I'll leave the 24 volt exterior stuff on so i don't have to plug up the holes. I think the black out light and the switching is all in the 12 volt side of the circuit so that should still work. I am going to ground , ground , and ground again. The one alternator that came with the truck might be a isolated ground so I will keep that for another M1008 that is 24 volt as a spare. I will keep all the 24 volt stuff as spares for the 24 volt system.
I am considering what to do with a M1028 I have as well.It is missing the alternators and the air cleaner was off of it and it is dented on the drivers door and the windshield is missing and the motor pool condemned it cause they didn't check the port side wheel and all that is holding it on is the brake caliper. It has 30,xxx miles on it but it is somewhat rough so I thought install rockwells, A3 wheels and tires. 205 divorced transfer case, an 800 hp BBC (with 1280 cfm throttle body and whitebrosracing dual fuel electronic fuel injection- 105 leaded turbo blue + E85). I have the stuff sitting around and the help of a 24 year old full of P$#s and vinegar to help build it so Hmm. I would keep the residue 24 volt stuff as spares so this one would go to 12 volts as well. The M1028 is rough enough that it is not worth the expense of restoring (more into it that could sell it for) and the axles will fetch more that I paid for the truck so... a green camo hot rod for pulling??? and some street legal fun. Why break a $50,000 super duty in a truck pull.
whaddya think??