I am looking to begin welding new framework early next week. I have read on here that I should disconnect the computer and other things, but i forget exactly what it was, and i have no idea where to find it.
Thanks guys!
There was a pretty good thread on this subject a while back: http://www.busconversions.com/bbs/index.php?topic=10086.0
Lots of discussion back and forth. One of the suggestions was to unhook the battery cables and then connect them together (off the battery). I had asked if anyone had tried that, and I don't think I got any good feed back.
Jim
Yup, all of that is good advice...I wonder why??? ;D :D ;D
God bless,
John
My DDEC books tells me to simply un-plug the harness from the ECM and to also disconnect the batteries! Didn't say anything about grouping them together though! My ECM is located on the rear center of my 8v-92 on top. The harness plugs are two side by side on the curb side of the ECM. The plugs have a small bolt in the center that is hard to see but you have to loosen it first or your doing nothing!
Ace
We just disconnected the Tranny computer, engine ECM, and the batteries. (To abbreviate the thread posted above.) Also, if you have house batteries or inverters, make sure you take care of those too.
God bless,
John
John, where is the tranny computer located?
Whatever you disconnect to be safe is a good idea. The main thing when welding is keep the ground close to where you are working. I work in a plant that is computer controlled with plcs. We weld every day with no problems. Electricity will take the shortest path. Keep this in mind when welding. Hook your ground as close to your work as possible.
John
Quote from: iminaccess on December 25, 2008, 07:15:41 PM
John, where is the tranny computer located?
Ours was on the rear wall, driver side, first bay. I don't know where yours would be, since we have a DL3. If you can't find it, call MCI tech support. They will know (if somebody here doesn't).
HTH
God bless,
John
Jriddle has the correct answer. I have a portable service truck that we weld off of and have never experienced any type of computer or alternator problems. In fact in my 30+ years of welding I have never experienced a problem. But it doesn't hurt to take extra precautions. Just keep that ground clamped directly to what you are welding on.
Do you have an electronically controlled engine and transmission in your 1981 MC-9?
No disrespect is intended at all, early 9's we had were all mechanical - non DDEC, non ATEC.
If you do, check inside last cargo bay on streetside (L/S) and look up. You'll see a cover with Dzus fasteners, check that. Good luck.
Quote from: Sammy on December 26, 2008, 06:10:43 AM
Do you have an electronically controlled engine and transmission in your 1981 MC-9?
No disrespect is intended at all, early 9's we had were all mechanical - non DDEC, non ATEC.
If you do, check inside last cargo bay on streetside (L/S) and look up. You'll see a cover with Dzus fasteners, check that. Good luck.
Thanks Sammy, I didn't know what the MCI 9's had. Thanks
God bless,
John
My Dina says to remove the fuses for the DDEC and WTEC along with removing the ground for the equalizer before welding. I can't find the fuse for the WTEC so I just disconnect the plug from it.
Middel bay, driver side,,, crawl in the you will find a panel the length of the bay that will pull down with a little luck and a large screw driver, it will open down. Watch out for all the dust and dirt that will come with it. If you have a ECM it will be located there. Disconnect everything and you should be safe. Along of course with the batteries.
At least that is where mine is.... :) Or just do what Sammy said..... ;D
MCI-9 83 with a ATEC....
Bill
I had a buddy that thought the lug nut was a nice convenient place to hook the ground clamp. Welded fine but when he went to take off, he noticed a little extra to overcome and get the truck rolling. Then mile or so down the road the wheel was flopping. :D seems the bearing was the highest resistance in the circuit and welded it self together.
It was a lot funnier listening to him tell it but i hope it helps somebody. ;)
Bearings are not a good thing to pass though when welding. All one has to do is just imagine where the electricity has to go through when welding and keep it as close to the work as possible. I have welded on computer controlled curcits that should have been disconnected to keep circuit boards save with no problems. The trick is to know where the path the electricity wants to go and ground to your work. Bearings and circit boards aren't what you want to pass though to complete circit for welding. If you feel better unhooking things. I not going to tell you that that is BS, but you can save a lot by being smart about the flow of your welding circit.
My experience John
*** We weld every day with no problems. Electricity will take the shortest path ***
I will politely disagree;
1. Electricity AWAYS follows the path of LEAST RESISTENCE not necessarily the SHORTEST PATH
2. You have been lucky so far
FWIW
Quote from: NewbeeMC9 on December 26, 2008, 07:17:23 PM
I had a buddy that thought the lug nut was a nice convenient place to hook the ground clamp. Welded fine but when he went to take off, he noticed a little extra to overcome and get the truck rolling. Then mile or so down the road the wheel was flopping. :D seems the bearing was the highest resistance in the circuit and welded it self together.
It was a lot funnier listening to him tell it but i hope it helps somebody. ;)
Where is Quantum500, when you need him? I posted a similar story in the thread posted above, and he said that it probably would never happen. Nwbee, thanks for the confirmation ;D ;D ;D.
My point? Do as the others have said and keep the ground really close to where you are welding.
God bless,
John
Niles500
1. Thanks for the correction your words are what I was looking for when posting. I'm not saying that you should weld with things hooked up. My point is that one should ground as close to what you are welding when possible.
2. I guess you could call it luck. I call it a necessary part of the job. We have a multi million dollar plant and do not have the luxury of shutting everything down when some portion of the plant needs fixed.
I stand corrected John
Quote from: Jriddle on December 27, 2008, 08:22:52 AM
I stand corrected John
Jrdl,
What does that mean? I didn't know that I corrected you on something. Were you trying to be sarcastic? I am not trying to pick a fight...Just curious.
My point on disconnecting the computers on the bus, was just that doing a little preventative, might save a lot on the wallet. I am not saying that it happens every time, but I sure wouldn't want to spend $$$ on a computer when I could have avoided it, but again that is just my opinion.
JR, I wasn't saying that you were doing something wrong. Just that with a little application, like a bus, it might be best to disconnect what is possible.
God bless,
John
John - He was referring to me (correction is too haarsh a word - sorry if it came off that way) - Jriddle I'm sure you can make an educated guess on where to ground, but some reading the board may not. It's still risky w/o the disconnect - FWIW
If it were my Plant, unless it was a true emergency, I would do maintenance during idle or shutdown (unless your 24/7)
Niles500
That is the problem 24/7 365 Something is running.
I here what you are saying. Some may ground to frame when they can ground a foot from where you are welding.
Thanks John
Niles,
Good, I didn't know if he was referring to me ;D ;) ;D.
Still, if at all possible, I agree with John (aka Niles500). I also understand there are the commercial places (like Jriddle) that can't shut down to fix something. It is just best to prevent, if at all possible.
God bless,
John
John316
I hope all didn't get me wrong I Used the wrong words in one of my post and was glade Niles500 corrected me. If one can unplug things to protect them that is best. My point is you still don't want to take chances by grounding to far away, who knows what you are passing through.
John
I got you...Thanks. Good explanation. I just didn't know if I was the "John" that was refereed to. If I was I couldn't figure out what I said ;D :D ;D. (Can you tell I need help sometimes??? ;D :D ;D)
God bless,
John
John,
I also figured out that you just signed you name at the end. I also figured out that Niles500 isn't John, that you are ;D :D ;D. I am sorry...I guess I am tired, or is old age setting in? LOL ;D :D ;D
God bless,
John