WONT START! Miller WildCat 350D WELDER

Since a strong welder is no doubt of use I've come here for some assistance. Since its a diesel...and I'm no diesel mechanic...I'm sure more than a few people here have forgotten far more about said engines than my limited knowledge. I understand the basic function but thats it.

As said in the title its a 350D Wildcat circa 1980. Goes up to amperage beyond anything I'd use it for. At the same time it wouldn't be out of place in places such as big oil platforms and upper end contractors (private or otherwise). Picked it up last November for $1800...quite a bit cheaper than I've seen them go elsewhere.

The problem: It won't run now. Also now the oil//temp light comes on.

Was using it earlier today briefly but as soon as I noticed a significant oil leak coming from the oil pressure sending unit. Turned it off...and hope I didn't hit the kill switch at a bad point.
Nearly broke the stem on the sender (has to have it to clear the oil filter mount). Had to rig up a replacement stem and used a spare non-specific sender unit. By this time this was done the engine had cooled enough that it was going to be a hard start. With myself at the switch//push button I had dad give it spray of starting fluid onto the air filter element (its mounted horizontal on top of the welder. [b:4b9a724742]NOTE: I wasn't paying attention and he sprayed enough so the air filter element dripped! I sure hope it wasn't overdone.[/b:4b9a724742] Got it started and it seemed to run rough (use earlier was fine). The oil//temp light had come on.

Now...the welder has a safety switch in it to auto-shutdown if temp gets to high or pressure too low. However was able to get it to run again after trying the OLD sender but still the light was on and it ran nowhere near like it did BEFORE killing it when noticing the oil leak. [b:4b9a724742]Could a damaged sender be causing an issue where it doesn't know if it wants to stay running or not?[/b:4b9a724742]

I'd just as soon bypass the safeties so proper gauges can be installed...never liked dummy lights.
Also...when turning the OFF//RUN switch to RUN...only the AMP light ever came on before and would go off once it got running. Turns out after looking at the manual I found for the welder...that the OIL//TEMP light should be on too with the switch in RUN with engine off. That light didnt ever come on until AFTER the sender leak//fix was done. [b:4b9a724742]IF its a matter of a working sender to make the safety system work proper...would a common oil sending unit work in its place and HOPEFULLY keep the safety shutoff from semi-tripping?[/b:4b9a724742]

I have several questions and observations:

1) What brand of engine does this welder have on it??? Miller does not make engines they buy them. With the model of engine you should be able to match a sender to motor.

2) Why not just buy the correct sending unit for your welder??? That way the safety system would still be intact. You really need that on a welder. You are welding not standing there watching the gauges. I would get the auto shut off working before I used it much.

3) Why the heck would you be using ether on motor when it is this warm out side???

4) You very well could have damaged the motor with ether. The smaller the diesel the less either you can use safely. I have seen bent connecting rods and other internal damage caused when either was used on small diesels.

It's ether not either but it could cause major damage if the air filter was dripping! That's beyond excessive. It's probably a good thing it didn't start. If the welder has a Murphy switch set up and it had an oil leak, it's supposed to shut down. If parts for the Murphy set up are broke, they need to be replaced with the correct parts, not something that will fit. That could be the exact reason it won't start.

Never heard of 350 Wildcat before. I'd guess the engine is a Perkins or a Continental as that's what Miller has used in Trailblazer 55D's that are 350/400 amp machines. They have also used other engines. Sometimes people with no experience with diesels or machines in general should REALLY get a manual and perhaps find someone with experience before they try to do anything with it. The poster may have just cost himself a few thousand dollars in unnecessary repairs.

The first thing to do is look at Millers web site and download/get a copy of the manual for your machine, and print it out. Do a search for Wildcat 350D, but if it doesn't come up that way go to nearly the bottom of the list because that's where it's listed alphabetically (Wildcat)-vs- numerically (350D). I've got one of those machines with the Waukesha diesel so I know the setup your looking at. Too there are full wiring diagrams in the manual.

That said, the chances you damaged the engine with the ether are minimal give the situation you describe, so I really wouldn't worry about that. Not saying it can't happen but no likely unless you kept cranking on it and it got to knocking from being over ethered.

That said the sending unit, the one that turns on the idiot light, is a part of the safety shutdown system. As such it works in conjunction with the rest of the Murphy shutdown system to protect the engine should it lose oil pressure or overheat. That being the case the switch, according to the wiring diagram should be a normally closed switch that will open when oil pressure is supplied to it, and close to ground when oil pressure drops. This causes the shutdown system to drop power to the injection pump and shutdown the engine.

Basically what I'm telling you is that you don't want to replace a system that automatically protects the engine wether you are watching it or not, with a set of guages that will allow the engine to over heat, run with no oil pressure, etc while your at the other end of a 50 foot lead and non the wiser that your engine is on it's death bed.

Beyond that many 'senders' as your calling it (it's actually a switch) are designed to be NO vs NC. If the one you got was NC vs NO, it would shift to the wrong position when you started the engine and cause both the light to stay on and the shutdown system to not send power to the injection pump...so it will not run... Now,if the old switch is making a little, but not quite enough it could possibly cause the system to send enough voltage to the injection pump to turn it "ON" but not necessarily enough to turn it all the way "ON". Too there is a fuse in with the over ride button and it may be partially blown causing the same problem.

Ultimately if I was there it doesn't sound like the problem your having is too complicated, but trying to tell you evertything to look at, and how to do it online like this is near to impossible. Your best bet, again, will be to get to Millers site and get a copy of the manual for your machine, with a diagram that will tell you evetything you need to know about the electrical system/shutdown system that you need to know.

Below is a link to their site and the page to get the manual. Good luck and post again if you've got any more questions and/or info that would help troubleshoot remotely.
Millerwelds.com

Listen to NcWayne and JDSeller, they are right on
with the safety switches. My brother was pumping
concrete one day and was on the remote about twenty
feet from the truck. The engine suddenly shut down.
An engine oil line under the truck going to an oil
cooler ruptured and dumped all the engine oil on the
ground. Would have been a lot cheaper to have had
engine shut down safety switches on it.

my thoughts are when you tried the 'non specific' sender, you took out something else, see if it uses a module.

So I didn't have to sit there and hold the button for 15 seconds I give it about 1sec spray but no more. Again I wish dad's and my position were reversed when starting it...myself with the can and HE at the button. For the start after attempting to repair the oil leak...I certainly hope the ether didn't ruin things. Hindsight now says it REALLY DID NOT need that shot.

It has the 4cyl Waukesha, Model VRD155A.

To date, the welder's control face has been within arms reach most of the time. Though did have the leads run out about 20ft when putting a hoist together that was to be used to support the tractor when dealing with wheel mount//dismount. But I see what you mean. Personal preference's aside I'll leave the shut-off safeties in place.

The "non-specific" senders, one of them that was tried had the short stem...that needed an extension to get past the oil filter mount...that was in my grandpas old toolbox. The other was a working (when removed) from my truck when I converted IT over to real gauges. Didn't think the different senders would matter. Clearly Murphy's Box found neither appropriate.

I had gotten a PDF manual off of Millerwelds.com some time back for the welder but it isn't really of use since all it says to do to fix it is take it to an authorized etc etc. No place like that around here. However it does say what could cause the non-start.

Just had confirmed what was said here, that it is most likely the Murphy box behind the non-start. While I was at work he called up a local parts supply shop that does automotive//offroad//boats and said much the same about the box. Apparently it's an issue on some performance boats as well. If the oil pressure switch...doesn't work proper (it did crimp on me since it was in so damn tight and had to use a set of channel locks to get it loose before remembering I had a socket to fit it)...then it won't run//start right. Lovely.

Got home too late to go and get a replacement switch. Dad said the place has them (they have a long-necked one but not sure if it will be the RIGHT one) so will have to see from there after getting it tomorrow on the way home from work.

NOTE: When looking behind the panel last night to look for the safety shut down mechanism if only to confirm its placement, after looking over the wiring diagram, the fuse on the underside of the Murphy box a PO had wrapped it in tinfoil...and the fuse element was cleanly shot.
ALSO
At the very least is it possible//advisable without compromising the safety shutoff, to use T fittings at the temp//oil switches for that extra bit of visual confirmation. Doesn't do in my mind if say the engine shuts down to leave one wondering if its either temp or oil to blame. IE, if its witnessed starting to run too warm, it can be attended to.

Hmm. A Murphy box. There for when Murphy's Law decides to hit you while trying to be helpful at the same time.

Teeing in a gauge AND the Murphy switch is a great Idea. Also the running rough could very well be the wrong sender only half way turning the Murphy system off. We used to put them on tractors that ran manure pumps. They can be touchy to get set right but can really save you from a major repair.

The ether more than likely did not hurt your motor. I thought it might have been a smaller diesel like a Kabota or Yanmar. Those two are real easy to mess up with ether.

Just realized I misunderstood the label for the SAFETY SHUTDOWN SWITCH. When I'd read the replacement nameplate I have (the one on the welder a PO had painted over rather thoroughly...barely had gotten enough off to get the name//model off it after purchasing it, I kept reading it as HOLD UNTIL ENGINE STOPS.
When looking back at it...and confirming with the manual...it looks like its an override to be [b:f860cabf16]held until engine starts[/b:f860cabf16] (if a good fuse is in the Murphy). Try it if engine still refuses to start once a new fuse is in place and the tentatively-proper-oil-switch is installed?

Well, new fuse in the Murphy and sending unit (looked identical to the one removed). Still no start but the light will BLINK now. That's an improvement. <sigh> At this point now I think the Murphy Box isn't working right. Even in daylight I should see diesel smoke coming out the exhaust when cranking until it starts. There is none. It ran briefly on a spritz of WD40 but died almost immediately. Hopefully its as simple as the Murphy just not sending power to the injector solenoid. Disconnecting the oil switch and using a different one was probably the last straw for the box...that foil wrapped fuse probably never helped either.
Getting some professional help tomorrow to better troubleshoot the issue before going further. Hindsight, the PITA it is, had me recalling a stubborn seen-better-days workhorse of a diesel mower from last week. The fuel cut-off solenoid wasn't working fully...if only partially in it ran slow: The welder (the last time it actually RAN) ran slow just the same instead of revving up to its standard governed 1850RPM.

I apologize if I come off as "derr" (buck tooth, cross eyed cartoon character comes to mind), about this but its frustrating enough for myself since I bought the welder and would have to cover any repairs. Even worse for dad since it was my finding the welder that made it a godsend to help in the shop. What might take an hour and maybe a gallon of diesel beats the hell out of MANY hours and half a tank of acetylene (oxygen doesn't go as quick).

You hold the override switch down to get the engine to start. Then you keep holding it until the oil pressure is up and then you let go.

On these systems you should hear the solenoid click when you push the over ride button down. They really are not that complicated to deal with.

(quoted from post at 22:02:43 09/24/13) You hold the override switch down to get the engine to start. Then you keep holding it until the oil pressure is up and then you let go.

On these systems you should hear the solenoid click when you push the over ride button down. They really are not that complicated to deal with.

Click to expand...

I hear the "click" but still wont start on its own. Did enough cranking that the deep cycle battery I got for the thing is started to chug a little bit. Oil//Temp light would blink out when cranking so it IS getting pressure. Needs a spray in the air breather to even kick over. At this point I think that Murphy box is being temperamental. After discovering the wire layout I checked for power at the injector pump terminal with a test light...nada. I get continuity but thats it. In a short bit (within the next hour of this post) will be getting that assistance spoken of.

At this point I just need to know if the thing will still run, and want a more experienced hand just-in-case if I have to bypass the Murphy because of an electric fault in it.

EDIT: All is working back the way it was after first purchasing the welder and using it from time to time. Appears to be an issue somewhere between the oil pressure switch and the Murphy...annoying but far better than all seemed before...but fully intend to trace down.
Still plan on installing real gauges though as addons under the engine cover.