On-Board Welder

[Dukes69]

you need to throw that million dollar camera in the garbage where it belongs.

[NAILER341]

that is my elph... something is wrong with it.
the million dollar one works fine

[jmbrowning]

Pictures are best.

My photo was a wiring flub-up.

Hand-drawn art is a close second


Original Wiring schematic




Welder Installed schematic





Welder Bypassed schematic

[jmbrowning]

Check that your wiring looks as above. If you are still not providing charge, check your field fuses as they may have blown and your alternator is spinning without a field current.

The wiring instructions are quite a bit confusing and I had to call Mobi-Arc to get it all straightened out. Hope this helps you.

[NAILER341]

this is how i have mine wired. except i do not yet have the bypass wired to the ecu. i'll call them this morning to confirm what to do with the part that is normally on the alternator.

thanks for all of your help and input on this thing.

[NAILER341]

this is much easier than their instructions make it out to be.
both greens go to the same field connection, and both blues go to the other field connection.
i dont know why they would have doubles of each.... it just opens the door for confusion.
the gray goes right to the mobi arc red, and violet to ignition switched power.
that is it.

they did suggest a ground wire from the negative terminal of the battery to the alternator though.
well, i am off to the welding supply store for some cable.
i'll let you know what the final result is.

[NAILER341]

well, i got it in there and working.
it is doing everything it is sopposed to.
i do however have a check engine light, and cant seem to get it turned off.
there are no codes though.
i hooked it up as stock, and the light goes out.... weird.

[blkTJ]

glad ya got her workin'. what about that plug in question and your battery isolater???

[jmbrowning]

Apparently, the Mobi-Arc puts out a set voltage around 14.5 volts. The ECU adjusts the charge voltage. It will see the "wrong" voltage and trip the light. I think Scott and Doc can change out a resistor that will change the voltage to something the ECU "likes".

[NAILER341]

glad ya got her workin'. what about that plug in question and your battery isolater???

that thing just gets set aside.
i am not using the isolator at the moment, and have it wired to one battery.
i just wanted to try to get the thing working.. then i'll redo all of that wiring mess.

[NAILER341]

ok!
well, this thing is in there, and i finally got the check engine light to go out.
i was getting an "open field" error from the alternator, which was causing the check engine light tto come on, and not allow the alternator to charge.

according to the engineers at mobi-arc, i am one of a very few people with this particular problem.
the computer is tricked to eliminate this error by putting a lightbulb between the field wire connections on the original harness, which was otherwise abandoned.
strange..
not a big deal except if the bulb dies, it will not charge the battery. so i obviously have a spare bulb. the trick is finding out how long the bulb will last. i got one that is sopposed to last 10,000 hours, but it doesnt say how many times you can turn it on and off.

i have made a couple of welds using the ready welder conected to the poles. it seems to have welded nice, but i havent really tested it yet.

i have also tested it using sticks. it worked oook this way, but that is primarily because i have no idea how to stick weld, and kept burning the sticks.

i will do more testing with it, and post up some pictures when i get some more time.

the unit is very well regulated to 40 volts and doesnt seem to fluctuate much at all. i will test this more as well with the hand throttle and see how i can manipulate the weld.

pics and info to come.

[jmbrowning]

Great to hear that yours is working! I got mine back and found out it was a bad ignition hot 12v connection. It checked out on the tester just fine. I am surprised you have to turn your field wires into a drop light for it to work! Can't you just measure the resistance of the bulb and put in a similar resistor in the circuit?

I am fiddling around with installing a hand throttle on my Jeep. I am also trying to figure out a way to get the wires to run to a quick disconnect on the front of the Jeep. Ideally, I'd like everything to terminate on the front bumper so I can weld without popping the hood.

[NAILER341]

well, the light was their reccomendation. acording to them i am one of 3 people that have had this problem. not sure i believe that, but .... oh well.

i used a 1 watt indicatir bulb like you would use to show that a switch is on or off.
at least it is a pretty green one :yay:

[jmbrowning]

Well, got things setup to do a little welding practice. I figured I'd do a bit of "real-life" welding without using really nicely prepared steel. I rustled up a little something which had been bothering me as a test mule, my .22 rimfire dueling post. That POS is made of two separate pieces of angle iron held together in a lap joint with a bolt going through it, wobble city.

The thing was powder coated or perhaps just painted with some kind of latex finish. I didn't bother to use a wire brush or angle grinder/wirebrush to clean up the joint. I just pinned it to the ground with a brick and fired up the Jeep. I hadn't installed a hand throttle yet as I was too lazy. The Wife was busy inside reading something important so I couldn't bug her to put on welding goggles and keep the engine RPM's at 2000. Instead, I just pressed the throttle down to an appropriate level of engine whining and applied a surgical clamp to the throttle wire where it came out of the firewall.

6011 rod at ~1800-2000 RPM got fairly good penetration and rod deposit, but it was a pretty crummy weld (first stick welding and lots of burning paint in the weld too). The vapors from the burning powdercoat/paint were quite nauseating as were the exhaust fumes from the Jeep (don't weld too near the back passenger side of the Jeep). Held together pretty well.

Lessons learned:
1) I am a crappy stick welder (even worse than my MIG welding).
2) Don't inhale too much if you are going to weld through powdercoat.
3) Throttle control is needed to get a good weld and I recognize I am too lazy and shiftless to install a brake cable hand throttle.
4) Find a solution that is easier to install even if it is a bit more expensive.

http://kwanms.com

I read about this on Stu's site a while ago and I was thinking about it quite a bit while I was wrestling with my Kelly clamp and gas pedal. I got a chance to meet Seek Kwan when I picked it up and it seems to be a very interesting little device. His TJ is pretty trick and his custom Sanden OBA is very slick as it lets you keep the stock airbox in place.

I'll post a pic once the throttle winch control is installed.

[NAILER341]

well, i have become completely disappointed with this thing. it is being removed from my jeep, and sent back to be repaired [hopefully they dont try to charge me] and sold on ebay to the highest bidder.

on the calico trip, after some relatively heavy winching the mobi arc fried from the current draw the winch was putting on the system.
per my conversation with the mobi arc engineers, they are guessing it is multiple "fets" that have taken a dump. fet- mosfet

i will repost once i get the word back from mobi arc on the damage.
i am, however no longer interested in this piece of equipment. it has been more trouble than it is worth the whole way through.