Greetings All. I was wondering if anyone knows how the B+ lug stud in the PDC under the hood is connected inside the box. I want to disconnect the B+ cable but when I start to turn the nut the cable and lug start to turn with the nut. From what I can see it looks like the stud base is a square and has a little play then tube locks in a slot. I'm just a little afraid that it will spin if I continue to turn the nut and will break something causing me to have to replace the entire PDC. I sprayed a little penetrating fluid on the nut and am letting it do it's thing. PO has another fuse/wire connected there that I want to remove is the reason I want to remove the nut. I cant find anything in the manual and prints are no help so any advice would be greatly appreciated

 

Is it really stiff? Or, did it come off a bit, then start spinning? I suspect that there is a bolt-head shaped recess it fits into, that keeps it from turning, so, pull up on it, and turn it to get it to re-engage the recess, and finish removing the bolt. Keep in mind, if you let go, it will probably fall out.... No clue how it was originally held in.

 

Thanks for the reply HeyYou. It's stiff and tight, and not stripped, and doesn't look cross threaded. I scribed a line over the nut and stud and it looks as if the nut moved about a 32nd of an inch after the stud tube locked so maybe I just need to wrench on it to see if it breaks free. I just envision a mess of wiring or transistors underneath twisting if the stud turns because I have no idea how the B+ stud is connected internally to the rest of the works. I thought about using a Dremel cutting wheel to just cut reliefs in the nut and pealing it off but not a whole lot of room in there and I figured I'd check here first before doing any more to it. I'm using a wrench rather than a socket also so I can see what it's doing without doing any unnecessary damage to it.

 

Can you get a look underneath with a mirror or something?

 

Yes a mirror and flashlight, and that's where I saw it looks like a square block base encased in the PDC plastic housing by a slot, and it must come up through a hole to the top of the PDC where the B+ connects to it. For all I know it could be a stud threaded into that block but I doubt it because there would be no way to thread it in other than the nut holding the + cable to the stud. I haven't tried but I have some tappet wrenches that I may try to fit into that slot and get on the squared base but I really don't think there's clearance. I'm always afraid working on these things because for over 40 years I worked Detroit's, Mac's, Cummins etc. and torques and things were much higher than on these trucks and plastic was minimal on them so I have a tendency to accordingly torque by habit and get cold feet on these little trucks. By the way the PDC looks fairly new, the P/N sticker is bright and not weathered. It was a city or county truck all it's life so I'm fairly sure it's been maintained professionally. 162K miles, it's fine as it is but if I ever have to change the + cable I'll wind up dealing with it then so I figured I'd tackle it now. I really appreciate you're input and reply's though as I'm just a tad nervous with this being it's on the PDC ($$) and all, and I don't necessarily HAVE to mess with it.

 

Do you have the service manual for your truck yet? If not, get one here. There *might* be useful pic in there of how things go together, but, I suspect the PDC is 'non-user-serviceable' part.... though, they likely have the procedure for changing that cable, might be enlightening.

 

Yes, I had downloaded the 2001 manual and it has almost the same info, minus any real pics as my 2000 factory manual. It is just a nut and the manual says to remove the nut so I guess there's no mystery to it. Now the 2000 manual I have gives the torque to the B+ nut on the PDC as 75 in. lbs. where the 01 manual doesn't say anything as to torque when assembling. I don't think I used 6.25 ft. lbs. of force in trying to remove it because I saw the stud and cable moving till the base of the stud tube locked in the slot underneath, so it should come off now that I have an idea how tight the nut is on there and have the procedure verified by the manual. So I'll get over my jitters and just give it a little more oompf and it should break loose ok. I didn't see anything in the manual the first time I looked because I was keying on searching the PDC and it was under battery cables in the battery section. Thanks for re-directing me, I really appreciate you.

 

That's quite normal for the cable to turn with the nut. Numerous times I've been scared of breaking something when removing the cable from the alternator or starter. Usually those cables have been in cavity that stops the the cable from turning if the nut doesn't break loose first. But if not such structucal help, I've used screwdriver or pliers to hold the cable from turning. If there is no visible corrosion, nut usually breaks free quite easily when rest of the parts don't turn along with it.

 

Try a 1/4" or 3/8" impact driver to buzz it off. Doesn't work all the time but it's something else to try.

 

Thanks for the tips guys. I've been doing chores today before the rain we're expecting this week so I haven't done anything more to the truck yet, but I'll be getting to it soon. No visible corrosion or rust at all. I'm going to replace the battery anyway, it came with an under rated 540 CCA one so I think I'll wait till then to tackle it!