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Kent

Big Ten wiring challenges....

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Kent
Does it matter if I check resistance on the switch when the switch is not in the tractor? That's what I did, and saw no change... Tim, I'm still a bit confused on your description of testing the new wire. If checking the new wire I put in, shouldn't I check resistance from one end to the other end, instead of from wire end to ground? It's an unwanted ground that's causing my problem in a circuit leg designed to provide a ground....

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Kent
Ok I'll bite. You obviously had it running beore you put the panels on? If you were able to run it and stop it before you put the panels i'll bet you pinched a wire. If the wire is where you can pull on it, back to the engine it should not be pinched. If you can't put one hand or fingers on one end and fingers on other end and feel pulling back and forth while you work it its pinched. If you take the wire off of the switch all together measure the Wire or terminal on the wire to ground if you have a short to ground it will show up. If you touch your 2 leads together you will see what your meter does with a short. The switch will work out of the tractor. Will it start without the wire connected to switch? Let us know Scott

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TimE
Kent, By measuring from the new wire to ground you be able to tell if it is shorted to ground. You measure from one end of the wire to the other for continuity. This will tell you if the wire has broken (open), but won't tell you if it is shorted to ground.

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TimE
Kent, If one end the "kill" wire is attached to the ignition points it will show as being grounded regardless of key switch position when the points are closed. This is normal. When the key is in the RUN position, the "kill" wire should read grounded/not grounded as the points open and close. When the key is in the OFF position, the "kill" wire should read as grounded regardless of the points being opened or closed. The easiest way to test this is with a simple 12 volt test light. VOMs can be confusing to use.

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Al
Hi, The above are correct. When the switch is in the off position [not running] the terminal is grounded to the case. I would disconnect the kill wire at the little insulated block at the point cover. Then I would check the wire to ground with an ohmmeter when you turn on the switch [Run position] there should be no ground on the wire and when you switch the switch off, it should ground the wire. If this is happening the wire and switch are OK. If you are using points and not a magnetron, you can then check from the terminal on the point cover to ground. When the points are closed this terminal is connected directly to ground. When the points open the resistance will increase a little because the primary winding of the magneto is connected directly across the points. If you do as Herb suggests and use a small test light bulb, you can connect one lead to the + of the battery and the other to the points and when you turn the engne over the light should be very bright when the points are closed and dim some when the points open. The light can be used to make the switch and wire test above and with the one lead connected to the wire instead of the point term the light should go out when the key is on the on position and be on when the key goes to off. If this is not happening disconnect the wire from the switch and check each individually. The wire should cause the light to light if you go to the other end and ground it. If this happens the wire has continuity and is not shorted to ground !!!!!!CAUTION: DO NOT USE THE LIGHT TO DO THE TEST AT THE POINT COVER TERMINAL IF YOU HAVE A MAGNETRON. ANY VOLTAGE APPLIED TO THE KILL TERMINAL OF ANY ELECTRONIC IGNITION MODULE WILL INSTANTLY DESTROY IT. EVEN WITH POINTS IF DIRECT 12 VOLTS [NOT THROUGH A SMALL LIGHT] GETS ON THE KILL LINE IN ANY WAY IT WILL MELT THE WIRES, AND THE IGNITION COIL WILL NOTIFY YOU WITH SMOKE COMING OUT OF THE BLOWER HOUSING AND THE POINTS WILL HAVE THE CONTACTS BURNED BLUE. If you have a Magnetron failure, Briggs has a service bulletin out that says to unhook the kill line from the engine and put a voltmeter on it and turn the switch to start position 25 to 50 times to look for transient voltage on the line. They say most Magnetron failures are caused by ignition switches that have particles of metal inside that intermittantly short 12 volts to the ignition terminal for an instant and destroy the Magnetron. They don't warrranty these. Sorry, TOO LONG, NUFF SAID. Good Luck, Al E

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B_WALLY_
Kent, are the points opening and closing properly? any stray strands of wire by the points? Sounds silly, but been there, done that!

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SmilinSam
The last time I had this problem it was not the switch, I was grounding the points out at the points when I put the cover on them. Loose or bare wire.

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Kent
OK, I got the first one solved -- I think. There was a short in the new wire that I had run, just at the edge of the side panel at the bulkhead.... So, I ran a new one and reinstalled the switch. Without connecting it to the points, it tests fine.... It has a ground when the switch is off, it does not have a ground when switch is on. I ran out of time to connect it to the points, reinstall gas tank, battery and test it.... And to answer some previous questions about how I got into this situation. I had not had the engine running without the side panels -- on these oldies the dash and side panels are one piece. Since the dash was already scratching the heck out of the steering column, I went ahead and bolted the dash,including the side panels, down before I tried running the engine. (I must have pinched the wire at this time.) Then, I proceeded to wire everything else, and tested starting the engine, still without the kill switch wired. After some carb and linkage tweaking, it started and ran OK.... Then I put new points in it -- old ones were in sad, sad shape, and started trying to get the kill switch to work.... This is an oldie (first year of the 243431) and doesn't have a magnetron nor a wiring block on the points cover. The points cover just has a little gap that the wires run through.... Thanks for all the help! This is a great resource we've got going here!!!!!! Next, it's time to fix the charging problem...

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Kent
A couple of electrical questions on my newly assembled Big Ten: 1) I'm trying to wire the "kill switch" for my Big Ten, following the diagram attached. It has a "kill switch" with only one wire attached to it. I assumed that this switch was to ground out the points/condenser to kill the engine, and ran a new wire for that purpose. But, when connected to the switch on one end and the points on the other end, it grounds out the points/condensor regardless of the switch position. I tried using a multimeter (I'm lost with using one) to check resistance from the wire terminal to the body of the switch, and saw no difference when you turn switch off and on... So, I thought the switch was bad. Next I substituted a "press and hold" switch off a different parts tractor that has two wire terminals. I connected one to the points/condenser using my "new wire" and the other to a ground point on the engine. Same story -- ignition is grounded out regardless of whether the switch is in or out... This is getting to be a pain in the @#$% since you can't get to the switch without taking out the battery and gas tank.... Now I'm beginning to think I may have pinched the new wire that I ran when I put the side panels on, and shorted it out. Any suggestions? Any tests that you'd recommend? As I said, I have a multimeter but don't know how to use it... 2) I wired the starter/generator, starter switch, and voltage regulator per the linked diagram. It starts and runs fine, but the ammmeter is showing a 5-15 amp discharge that increases with engine speed. It's almost like it's wired backwards. I verified that I have it wired per this diagram, though the posts on the back of the ammeter are not marked. The wire on the "outside" of the tractor, that also corresponds to negative side on the ammeter dial, is wired to the regulator terminal shown. Have I screwed this wiring up also? If I have time tonight, I'm going to start troubleshooting this gremlin, too, using Al Eden's suggestions in the Service section. But, on the off chance that one problem is related to the other, I thought I'd post my symptoms here for any suggestions...[A href='http://www.simpletractors.com/images/wiring/lighting.jpg']http://www.simpletractors.com/images/wiring/lighting.jpg[/a]

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Kent
Kent, I would think the switch needs to be on the 12 volt side of the coil supply. (thats assuming you are using a coil) If it's on the high voltage side it could very well be arcing across the switch just like a spark plug. Path of least resistance and all.............. My two cents......(refundable of course) Terry

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TimE
As an electronic technician by trade I feel qualifified to answer. When checking a switch with a multimeter, put it on the ohms (resistance) setting. When the switch is closed you should read zero (basically) ohms. When the switch is open you should read an open (infinity). Keep in mind that there are normally open switches and normally closed switches. The kill switch with one wire might short to the switch housing when closed, which is grounded to the dash to the frame to the engine. To check the new wire that might be pinched, again use the ohms setting. Measure from the wire end to ground, it should be open. If not, the wire might be pinched causing a short to ground.

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