Current leakage

[dsholler 54]

Any good clues about how to track down some stray current?
My 414 has corrosion on the top of the bracket that holds the battery in the box (you know, the bar with the two threaded hooky-thingys .... you can see I am very technical) big pile of white powder.

 

Because mowing season has just started up here in CT, I have been using the tractor infrequently (every couple of weeks) and each time the battery has been nearly drained..

 

However, I have no idea where this is coming from... I visually checked the wiring I could see, and there were no obvious worn spots where it was making contact with something else.

 

Anyone have a good game plan for how to track this down? It is getting kind of annoying.

 

[WH nut 553]

Replace the Battery, its bad. When you start seeing that kind of corrsion its because the battery is leaking

[dsholler 54]

I can do that of course, and it is quite possible the battery is bad, but there is no liquid on the exterior of the battery at any time when I start or stop using the tractor, and I just saw a nice little spark at the corner of the hood when I started it up... ugh.

[WH nut 553]

I can do that of course, and it is quite possible the battery is bad, but there is no liquid on the exterior of the battery at any time when I start or stop using the tractor, and I just saw a nice little spark at the corner of the hood when I started it up... ugh.

Well now you gave the information needed to trouble shoot. First off corrsion= acid leak, Now the spark means more than likely a bad ground someplace. Your starter is trying to find ground through the hood

[dsholler 54]

Hmm, I guess that is true, but then the question is how to find it? Your notion that it should be in the starting circuit is a good place to begin I suspect... Guess I should check the ground connections from the starter. The only issue of course is that the battery ground strap is attached to the sheet metal of the tower (which is where the spark jumped between the hood the tower, on the corner) so the issue could be the other way around.. that there is something touching the hood that is a better path to ground than the sheet metal, no?

[Save Old Iron 1,563]

you always come up with the most interesting stuff. I will take a look a the 416 tucked away in the barn this afternoon and get back to you with a few suggestions. Is the spark seen at the ground strap in the hood tower or is the spark seen at the junction of the hood and the tower?

 

If you have uncoated choke or throttle cables on the tractor, start the tractor and CAREFULLY touch the outer sheath of these cables to see if they are hot. BE CAREFUL as they may be very HOT!

 

By the way, what year is this 414 ?

[WH nut 553]

Try this for shits and giggles. Take some jumper cables and connect on lead to the motor, the other end of the same lead to Battery-. try and start and see if you get the sparks. If you dont then the motor isnt grounding to the Battery. Im not for sure how your tractor is set up, but most have battery ground connected to the dash tower then the motor grounds through the frame to dash tower. If the dash tower ground is bad, the motor will tray and ground through the throttle and choke cables, or through the head light circuit or any other path to battery ground it can find. Bad grounds make things go very goofy.

[dsholler 54]

The 414 is an 87. Most of the pieces are original...

The spark was new to me. I have only seen it once. It was between the corner of the hood and the dash tower.  The time I saw it, the hood was a bit askew (you know how you can flex it so it does not sit properly on the tower). I have flexed it back into position and I no longer see the spark. However, I have had gremlins in the past where it would not start at all until I shifted the hood into the proper spot, so I am guessing this ground issue has been there for quite some time. However, I recently messed around with the tower, so I may have changed something.

 

I have cleaned the ground connections to the tower... sanded and greased the contacts and the spot on the tower, and I have checked the continuity from there to the battery, the solenoid and the starter, all of which check out OK, but this was a few months ago.. so I probably should check again. The other thing that has changed is that I had the throttle shaft and bushings replaced. your thought about cables being paths to ground is interesting, since new materials may have changed the contact if it was using the throttle cable or something.. the cables are coated, but they are also original, so may be compromised someplace.

 

I think my next test will be to see if I have continuity from the dash tower to the frame, I guess. only bad news is that the paint on the frame is still pretty good, so I am not sure where to test. I will follow SOI's suggestion and see if the cables are getting warm. I am not sure I can try WH nut suggestion, since I am not able to consistently reproduce the spark.   It still leaves me with the question about the battery, and whether the corrosion I am seeing on the strap is galvanic corrosion or whether it is from gas escaping from the battery.  I suppose the smart thing to do would be to take the battery to the gas station and throw it on the tester.

[dsholler 54]

OK, had a few minutes tonight to look at it.. First, I charged the battery overnight. I think that WH nut may be correct, as I did notice a bead of moisture around the battery caps... so the corrosion on that strap may have been from some outgassing or leaking. However, I did not have a new battery handy, so I fired it up with the one I had. However, I may have messed up the test, because I did it with the hood open.   I ran it around (and took the opportunity to adjust the new sweeper I just picked up) (with the hood closed) and then brought it back. neither the throttle or choke cable were warm, and the covers appeared to be intact for the entire route.  I cannot see how either of them could be in contact with the hood. the only thing electrical that I can see that could possibly touch the hood would be the battery cables themselves, the spark plug wire,  and possibly a spliced wire behind the circuit board (I have no idea what it is, all of my safety switches work, so I think it was just a repair at some point) but this is covered with a wire nut that is more than adequate, and I made sure it was tucked down behind the board anyway.  f

Well, will try some continuity testing as soon as I get a chance. Any other suggestions will be most helpful.

[Save Old Iron 1,563]

Dan,

 

a few questions.

 

When you saw the spark at the corner of the hood, did you have the headlights on?

 

Take a look at the ground lead on the headlights. Is the ground lead intact ? and where is the opposite end of the ground wire from the headlights connected to ?  the hood ? or the frame ?

 

The spark you may be seeing could be from the headlight current trying to find a ground path back to the battery. I'll put together an explanation later tonight as to why this may be important.

 

I wouldn't worry yourself too much about resolving this as it can be fixed easily with a few well placed ground straps. Answering the above questions will allow a little learning to take place.

[Save Old Iron 1,563]

Dan
the diagram below shows the current flow thru the tractor if all the skins are grounded properly to one another. Black lines represent ground paths thru sheet metal skins and angle iron frame. Purple lines are current flow.




Now let's lift the ground between the dash tower and the frame



current from the battery cannot return thru the frame to the tower and the battery negative cable. Current flows along the path outlined in purple and jumps the air gap at the sloppy hood to hood tower junction. You see as spark there as a result of that current flow.



The reason I asked about the headlights is the spark you see at the hood / hood tower junction could be from a defective headlight ground. If the ground wire from the headlights are attached to the hood and not the frame, and the frame to tower ground is absent, the headlight current travels out from the battery - to the headlight - and must travel thru the hood and to the bare spot on the hood tower to complete its travel back to the battery ground. The spark you see could be the headlight current flow.



we need to assure the headlights are grounded properly to the frame and the tower skins are properly grounded to the frame. Without getting into disassembly of the tower and cleaning around the fasteners, a 6 AWG jumper could be run from the battery cable connected in the dash tower to a convenient fastener on the frame.The ground wire for the headlights can be 14 - 16 AWG stranded wire for flexibility. A braided ground strap could also be used at the point the hood pivots on the frame.
 

[dsholler 54]

SOI.. thanks for that...now makes a lot of sense. I will go and check the headlight ground later this evening. I am 99% sure the headlights were not on, because I had not used it at night, but there is a possibility that I could be mistaken. I did use the headlights last night and they worked fine, and I did not see the spark when I turned them on, but on the other hand, I was not looking for it either.  And of course, I have used the tractor several times this week and have not seen the spark and the tractor runs just great, so it is hard to say..

 

I think I may just put a ground strap on anyway.. There are plenty of holes in the frame (I think from where it was drilled for the larger engines).. I assume I would need to scrape some paint off there to get good contact for the ground. 

[dsholler 54]

Well, it does appear that the headlights are grounded to the hood.. at least I assume that is what the tab just inside the left one is for.. (and the left one is rotated 90 degrees from where it should be.... ) And there is a ground from the hood to the frame, although there is so much crud on the frame right there I could not even see the bolt. (lower right in second photo)

 

What does this tell us? is there any way that I can check to see if the headlight circuit is doing what you describe above? Or should I just add the ground strap and call it a day?

[Save Old Iron 1,563]

Or should I just add the ground strap and call it a day?

In a way, yes. I would run a new ground wire from one lamp to the next and down to the hood ground on the hinge area. I would also run a new wire from the hinge bolt to the engine mounting bolt. Use new terminals and clean the bolt areas on both the hood hinge area and the engine mounting bolt.

[dsholler 54]

Ok. I think I can manage that, except I need to get the pieces. Oh well, I needed a new crimper anyway.

[chazm 412]

Once you get the wiring fixed, from the looks of the hood & surrounding parts ,could use a good pressure washing   

 

 

ChasM

[dsholler 54]

ChasM... see my other thread ....

[chazm 412]

Already did... and it does look like you forgot

 

 

ChasM   

[Save Old Iron 1,563]

Dan,

 

if you don't mind waiting a week or two, I'll order the correct size ring terminals for the hood bolts and make you a headlight harness - no charge of course. No use in investing $40 into crimpers, terminals and wire, etc just for a single ground harness.

 

Let me know as I have to update two 416's this summer. Easy enough to make 1 more harness section for you.

[dsholler 54]

SOI if you are up for it, that would be fantastic. I will PM you.. Thanks a million