Wiring Harness

[Txstruck]

Anyone know where I might be able to purchase a wiring harness for my M1028?<img src="emoticons/icon_smile_shrug.gif" alt="Shrug">

 

[steelsoldiers]

Holy crap, a whole wiring harness? Now what are you into Steve? Try Front Line @ www.flmv.net They have lots of odd-ball stuff. I have seen harnesses out there, just can't remember where<img src="emoticons/icon_smile_nuts.gif" alt="Nuts">

 

[Txstruck]

I guess I finally fell from the stupid tree because I cant for the life of me figure out how to get the second alt. hooked up and charging. I printed those pictures you sent me of the alt and had him build it that way but I cant hook it up without sending sparks everwhere or making my glowplug solenoid smoke like a sib. <img src="emoticons/icon_smilie_bitchin.gif" alt="Bitchin">Where am I going wrong?? <img src="emoticons/icon_smile_shrug.gif" alt="Shrug"> I have a wire going to BATT lug with ~24v from the POS term board with a smaller wire with it going to a plug at the firewall. The wire that the schematic shows to go to the lug that was added also has ~12v..... Im lost....Im frustrated....Im just plain ready to give up on it. One thing that is confusing is I have 2 ALTERNATORS but the schematic shows GENERATORS... What am I supposed to have? Im begging for some help here.... <img src="emoticons/icon_smile_help.gif" alt="Help"><img src="emoticons/icon_smile_help.gif" alt="Help"><img src="emoticons/icon_smile_help.gif" alt="Help"><img src="emoticons/icon_smile_help.gif" alt="Help"><img src="emoticons/icon_smile_help.gif" alt="Help"><img src="emoticons/icon_smile_help.gif" alt="Help"><img src="emoticons/icon_smile_help.gif" alt="Help"><img src="emoticons/icon_smile_help.gif" alt="Help"><img src="emoticons/icon_smile_help.gif" alt="Help"><img src="emoticons/icon_smile_help.gif" alt="Help"><img src="emoticons/icon_smile_help.gif" alt="Help"><img src="emoticons/icon_smile_sad.gif" alt="Sad"><img src="emoticons/icon_smile_sad.gif" alt="Sad"><img src="emoticons/icon_smile_sad.gif" alt="Sad">

 

[muddobber40]

Txstruck, they are alternators. The TM diagrams are not the best. Tomorrow I will get you some pics of an engine bay on a truck I have or feel free to call 913-961-0548 and I will try to walk you through the wiring by phone provided my phone has service out there.
Also, I have got several harnesses. If i can't help you get yours figured, I'll get you a good deal on a harness. Oh yeah, another good source for CUCV parts is www.brtruckparts.com<img src="emoticons/icon_smile_thumzup.gif" alt="Thumb Up">

 

[Desert Rat]

Tex;
It sounds like you forgot to wet BOTH fingers before touching the wires (my wife wonders how I keep my hair so curly and never have grey hairs<img src="emoticons/icon_smile_wink.gif" alt="Wink">)!

But seriously, alternators and generators differ only in how the stator is wrapped in the windings. There is no real difference between the two. It sounds like a typical GM (oops, we goofed again, time for yet another mid-year change) design.

Usually on a 24 volt system you have one 24v alternator. The CUCV vehicles I've seen blend two 12v units to get 24v (see previous side thought on GM). Some of the trucks dedicate and alternator to each battery and some use a circuit board to really screw things up. My only idea for the board is to get a TM on the sob and start tracing the circuits. When looking at the recharging system you should be increasing the wire gauge (i.e. going to a 6, 4 or 2 gauge conduit) not the inverse. But then again, this is GM we are talking about.

I wish I had more help. Let me ponder this some more and talk to some people here next month when I'll have a bit more time to get to the Armory..... Hang in there! <img src="emoticons/icon_smile_help.gif" alt="Help"> is on the way!

 

[pvkj454]

The ground lugs on the alternators must be isolated, not grounded to the case. This would create sparks. It would be easy for the builder to leave out a plastic isolator on the rectifier bridge or the brush holder assembly. I have a 12 volt conversion guide from Roscommon Equipment Center that also has some good info on how the 24 volt system is set up and how it operates. I can e-mail it to you if you don't have it.

 

[Recovry4x4]

I concur with pvkj454. If you've had work done on the pass side alternator and not the drivers side, swap em! You can always unhook all the wiring and check for continuity from that lug to the case. If there is continuity, thats your problem. The passenger side is the one that gets 12V added to it to charge the batteries. Its a weird system in kind of a cool way. To help me when I was working on repairing the hatchet job, I printed the charging system schematic and took it to the printers and had it blown up quite a but then had it laminated. I stick it right where I'm working with a magnet! Harness is probably salvagable, just gotta find that oversite that no doubt exists!

 

[steelsoldiers]

Hey Tex, I thought you bought that alternator from the same guy that I bought mine from. I still have my old one laying around for parts if you need something.

Two things that will really screw you up are an un-isolated ground lug and a 24v regulator. I had a guy sell me a 24v reg. once and it made everything go nuts. Definitely check to see if your alt. guy put a fiber washer in between the ground lug and the case. Like the other guys said, that will cause fireworks<img src="emoticons/icon_smile_angry.gif" alt="Angry">

 

[Txstruck]

Heys guys thanks for all your help!! <img src="emoticons/icon_smile_cool.gif" alt="Cool"> Heres what I do know. Bought both alts from a guy I know here in town because he gave me a great deal on them. When he rebuilt the pass. side alt, he put 24v winds in it. Basically built a 24v alt for me. The second lug that he put in it is grounded from the case but im not sure about the rectifier bridge. The wiring harness thing was my girlfriends idea<img src="emoticons/icon_smile_rotfl.gif" alt="ROTFL"><img src="emoticons/icon_smile.gif" alt="Smile"> But I may still get one just to have on hand for the future. So muddobber, if you would give me some info on a harness in PM and we can discuss a price or something.

Anywho, Whats happening is when I hook the wire with 24v to the BATT side of the alt and the other wire with 12v to the new lug and then hook the batteries up, I get gobs of smoke from my glow plug solenoid so from what Ive read in these posts, it sounds maybe like the rectifier bridge is NOT isolated from the lug.<img src="emoticons/icon_smile_vconf.gif" alt="Very Confused">

So whoever wants to walk me thru the wiring on the phone ( I have free long distance ) We can setup a conference time and I can wet my fingers and jump in.<img src="emoticons/icon_smile_rotfl.gif" alt="ROTFL"><img src="emoticons/icon_smile.gif" alt="Smile"><img src="emoticons/icon_smile_rotfl.gif" alt="ROTFL">

 

[Recovry4x4]

Might be a problem here. If'n he built you a 24v alt for the passenger side and you're hooking it up with the factory wiring you will be creating a 36volt system. The alts are wired in series so if you add the 12 from thr drivers side to the 24 of the pass side, you got 36 man! Has this truck/wiring ever worked before? What prompted the alt rebuild?

 

[Txstruck]

Originally posted by Recovry4x4

Might be a problem here. If'n he built you a 24v alt for the passenger side and you're hooking it up with the factory wiring you will be creating a 36volt system. The alts are wired in series so if you add the 12 from thr drivers side to the 24 of the pass side, you got 36 man! Has this truck/wiring ever worked before? What prompted the alt rebuild?

What your saying makes sense and I agree because I am using the factory wiring. So my next question I guess would be how should I hook it up to get a charge out of it without using the 12v from the primary alt?

To answer your question, I useduse this truck as a daily driveroffroad truck and one day I was doing some hardcore wheelin and some of the trails were like a foot deep or so in muddy water which also prompted the oil pump replacement.<img src="emoticons/icon_smile.gif" alt="Smile">

But I must say, these trucks are tough! <img src="emoticons/icon_smile_headbanger.gif" alt="Headbanger"> and that day mine was running on muddy water.<img src="emoticons/icon_smile_approve.gif" alt="Approve"><img src="emoticons/icon_smile_disapprove.gif" alt="Disapprove"> I was hitting those trails so hard that it was splashing the water all over the engine bay and it ended up filling the little valley inside my air cleaner and I was steadily sucking it down the intake but she never died on me once. Within a week though I started losing oil pressure because sand was in the oil from the muddy water and it pitted the gears in the mechanical oil pump, and I believe it also was what caused the motor I just replaced to begin to knock. But all in all, it killed both alts also. Whew!!<img src="emoticons/icon_smile_tand.gif" alt="Tand"><img src="emoticons/icon_smile_smashed.gif" alt="Smashed"><img src="emoticons/icon_smile.gif" alt="Smile">

 

[pvkj454]

I think if the pass. side alternator was disconnected, the 24 volt alternator was put on the drivers side with the pos. terminal on the alternator connected directly to the 24v strip on the firewall it would work. It would not matter if the ground lug on the alternator was isolated or not this way. The glow plug relay would still need to be connected to the front battery and verified to be getting 12 volts. The 24v alternator could possibly have been damaged. I like the 12 volt conversion because it is easy and reliable. A 12 volt gear reduction starter is around $160 on Ebay. If you have 1 good 12 volt alternator the starter and a brace is all you have to buy.

 

[Recovry4x4]

Hmm, tough call. In theory you cold get by for a while utilizing the 24V alt and eminating the 12V but you will get into an imbalance situation with the batteries. If its all still original the glow plugs, which are 12V, will still work since it uses the resistors on the firewall to step down the voltage. The rest of the truck, however, draws 12V and will draw from one battery and cause the imbalance. Short term would work but problems will arise. Unless you are a purist, the 12V conversion might be the easiest way out. I gotta look for the URL but Roscommon Equip has the procedure for setting it up 12V and its pretty easy. I would thing the easiest way out would be to rework that 24V to 12V. As the previous poster said, not much to buy other than a 12V starter. Tough situation!

 

[Txstruck]

Ok, Lets say I wanna do the 24-12v conversion. Can you give me an idea of what kind of work is involved and a rough $$ estimate for parts and what-not? As a matter of fact, I believe I do have a gear-reduction starter already so I wont need to buy one.

 

[Recovry4x4]

Well, your gear reduction starter would need to be reworked to do the 12V conversion. Basically the swap requires moving some wires and cables and disconnecting the wires to one of the alternators. Go to www.roscommonequipmentcenter.com/news_notes/nn10.pdf
Your net investment will be changing the starter voltage. The swap involves a little wire splicing and swapping and removal of the left alt. Is the left alt still 12V? If it is, it can be moved to the right side. Check out the site above, its thorough and has pics. Pretty simple really. Let me know how I can help!

 

[Recovry4x4]

Just rereading the stuff. You don't really need a gear reduction starter, just a 12V starter. So whatever you end up with only needs to be 12V. Thats probably your only cost and maybe some wire and a battery cable.

 

[Txstruck]

Well the starter I thought I had is no good, but I caan get one that is 12v and gear reduction for about $100.

P.S. Thanks for the link. Ill be sure to bookmark it-read it-print it-and remember it. <img src="emoticons/icon_smile_tand.gif" alt="Tand"><img src="emoticons/icon_smile_tand.gif" alt="Tand">

 

[Recovry4x4]

Its a good page. I've saved it before but lost it. I've saved it again. Let me know if I can help. Looks like I'll be out of commission again for a while, another hurricane is bearing down on my back yard. I'll be checking in when possible.

 

[Txstruck]

Originally posted by Recovry4x4

Its a good page. I've saved it before but lost it. I've saved it again. Let me know if I can help. Looks like I'll be out of commission again for a while, another hurricane is bearing down on my back yard. I'll be checking in when possible.

Dang man! That blows! (no pun intended) Well batton down the hatches and keep you and yours safe! Keep in touch when possible and let me/us know if you need anything.

 

[Recovry4x4]

Thanks TXS. We'll be fine! Not the first hurricane we've rode out. Heck its the 3rd this year that has touched us. Man are we lucky, some people go through an entire lifetime and never experience a hurricane.