Unique battery wiring screw up on 09

So after all the last minute hook ups on the motor I just installed, I attempted to start it up. There was a large spark from the rear battery positive post, and the starter did crank the motor, then click click click. I had just done the starter relay mod and the glow plug bypass prior. (as a side note, I didn't hear the glow plug click, either...hmmm...but that's a topic for another thread.)

I looked at the TM to see what had happened, didn't find much, so I looked at SS for an hour or two. It dawned on me that it appears I made the mistake of running the cable from the NEG post on the rear battery to the POS post on the front battery, and the black cable from the firewall to the NEG post on the front battery.

Yes, I actually did that. In my defense, if there is one in this case, is that it has been a while since it was all put together properly, having taken me months to swap motors, and I just had a brain cramp.

My concern is how long and expensive the list is of things I may have screwed up. Before I dig into this further, I would appreciate any ideas as to what this list may have on it.

Thanks, and apologies if this thread is improperly placed....I simply couldn't find one that had such a colossal screw up.

Well, hang on.....I'm getting my brain wires crossed too...I may have actually had them wired correctly...I need to seriously think about this and get back...won't be till Wednesday that I can have a better look...I'm so confused right now.

and the black cable from the firewall to the NEG post on the front battery.

the engine block needs a ground also for the starter,...

dirtdiver said:

...I need to seriously think about this and get back... ...I'm so confused right now.

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I suggest you not think about it.


I suggest you draw it out. Stop trying to do this in your head. Make a diagram of what you have. Do NOT let that diagram be influenced by what you think it should be.

Draw what is THERE.

That will help reduce the confusion.

Now you can compare what's there to the TMs.

You can chase this around in your brain for a long time, and just get more confused.

The two front bats are wired for 12 volts, pos. to pos. neg to neg.creating one big 12volt battery, the two back batteries are also wired for 12 volts. The two "Big" battery assemblies are wired for 24V. I have a diagram on the underside of the passenger seat you can see with the seat lifted.
Note: The small wire attached to one of the battery post. That is the 12 volt pick up for the heater blower slow speed.

"To err is human to forgive is divine"

"To err is human to forgive is divine"

Click to expand...

We forgive you for posting incorrect info. He has a cucv, 2 batteries only.

Ok boys...here is what I did. I actually did have it all wired correctly, as far as what cables to what battery. However, I went back and checked ALL the connections and grounds. I found that when I did the doghead starter mod, the black (ground) wire was not crimped tightly enough, and very loose. Also, the small S wire to the gear reduction starter was not tight enough. After tightening, the thing cranked like it was gonna start, with no fireworks this time. My next task is to figure out why I didn't hear the glow plugs relay clunk, or cycle, or whatever you call it, then bleed the fuel filter. My spirits are much better now. I appreciate the guidance and for not making "short bus" comments. Ha.

Anyone reading this who are new to this addiction or just a shadetree mechanic like me, please take note of electrical connections, their cleanliness, and how secure they are. Thanks again!

Ok. So...to follow up on my last communication.....
Today I got two new 1050 CCA batteries, type 31, to continue where I left off on my last post. I had tightened the doghead relay and S wire on the starter. My intent was, after having successfully cranked the motor with no fireworks at that time, to bleed the fuel lines and get this baby started. I double checked the S wire and doghead relay. Hooked up the batteries, cranked it, and sparks flew again from the POS post rear battery. The starter whined but did not engage. I have changed nothing other than to add new batteries. I did have the GP's out in order to relieve the batteries. I was also going to check the GP relay for any problems with voltage, as I intend to modify the GP controller card with a manual pushbutton. I did hear it clunk while I checked voltage with the key on. the battery wiring is as follows: POS post rear battery from buss bar on firewall, NEG post rear battery from buss on firewall, as well as resistor bypass cable from top of GPR. From there, that goes to POS post front battery. NEG post front battery from buss bar as well as ground to chassis. I believe this is all correct, having reviewed the diagrams extensively. I am at a total loss as to what I am doing wrong. There must be something I am missing. Any ideas?

This is what I believe you should have. From your description, does not seem that you do.

There should also be a solid ground from engine to chassis or directly to battery so starter gets full 24 volts.

o1951,
I ran back and forth from computer to garage after reviewing your diagram. I have no reason to believe or suspect that the alternator wiring is wrong. From engine to chassis, I have all the straps and wires from the rear of the block to chassis. The NEG post rear battery also has a wire coming from the diamond above the GPR. The fusable link appears to be intact. Keep in mind I do have a resistor bypass in place. The front NEG has grounds, both clean, to frame and the crossmember to which the radiator is bolted, whatever that is called. ha. Both batteries appear to be correctly routed from the appropriate buss bars on the firewall. (POS to rear batt, NEG to front batt). My dilemma is that, after correcting some of the small things the last time, I now have sparks from the rear battery POS post. why would it do it again after making these corrections?

Post a picture or drawing of how they are hooked up and we will help you figure it out.

Have you moved the GEN2 alternator? Sometimes the terminals will come in contact with the mounting bracket.

I just attempted to make a video, but the Kansas sunset is just to powerful. I will get on this tomorrow morning and see what you all think. I do appreciate your help, but the video I just made is not of good quality. thanks...Jim

The above pics should show enough details as to how I have things hooked up. It was this way when I had success turning it over without the sparks after tightening the loose doghead relay and the S wire from starter. Mystified.

Warthog, as far as moving the alternators, yes, I have. They were off the same motor, but were dismounted for a short period of time while I installed the motor. In looking further in many posts here at SS, I have seen where alternators can cause sparking on the rear battery. I do not recall having any issues re-installing the alternators and they worked great when they were operating in the last vehicle they were in. Are you saying that there is a possibility of "shorting out" (for lack of better words) the alternator when I remounted them?

dirtdiver said:

Are you saying that there is a possibility of "shorting out" (for lack of better words) the alternator when I remounted them?

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Yessir!

One of those alternators is an isolated ground. Swap them and you have fireworks.

It appears to me that I have the isolated ground alternator on the passenger side, and correctly wired. Tonight, I pulled the glow plugs, hooked up the batteries as indicated, and was able to crank the motor without sparks and bleed the fuel, at least somewhat. Feeling upbeat, I placed new GP's, hooked up the batteries, and got sparks from the pos post rear battery again. It also sounded as if the batts were dying, as I haven't charged them since cranking. I will do that tomorrow. I am wondering if somehow, through all of this, that I have sizzled the glow plug relay. Or perhaps this is what drained batteries do? I suppose I will check that out this week. One of my goals this past weekend was to splice into the controller card and make a toggle switch to activate the GP's. Oh well, if it's not one thing, it's the other. Anyway, thanks for the input.

Update. Last night I cranked it over, still got some sparks from rear battery pos post, but not as much. Then I noticed the wire with the fusable link going from rear battery negative post to diamond 12v by the gpr was hot to touch and smoking. This is new. The fusable link does not appear melted. The only different thing I did was to take the large red battery cable from top post of gpr to neg post rear battery completely off and do the bypass by attaching the old wire from the top post of the gpr to the 12v buss next to it. Ive got my batteries fully charged and sometime this weekend will check it all with my voltmeter. I wonder if the gpr went bad somehow. Its a new one off the old 1009. I do have the old one, suppose I will hook it up and test it. This is driving me batty. I do appreciate any help. My daily driver, my explorer, blew the tranny today...eff my life.

Tested the gpr.. With key off 12v to top post, the rest 0v. With key on 12v at all posts except the bottom post, and it had a reading that started at 15 and began counting down towards zero..but never made it there before I took the test lead off. Not sure what to make of that. While cranking, I got no sparks, however, my fully charged batteries would barely crank motor and the cables got very warm to touch, especially the smaller guage from the negative post rear battery to fusable link going to 12v near gpr. So. I think my brand new 1050 cca batteries may have just taken a dump. Oh...and upon turning the key on to check things, the voltage gauge on the dash was in the yellow, even prior to the gpr clunking. Oh well