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Discussion Starter · #1 ·
OK we got the carb rebuilt on the MF16. Now it won't start with out jumping it. So far we have checked the battery and it has 12.50 or so volts. We have looked at the wires and fixed a few that was chaffed or had bad ends on them. The headlights do come on with the switch key but when you turn the key to start it does nothing. Now if you hook up the jumper cables it will start. Where would I look for the problem at now? Any advice would be greatly appreciated.
 

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Almost afraid to touch this one!! No expert here but the electric system on these little tractors is not very compicated and I've got the MF owners and shop manuels for the 1450/1650 tractors that has a wireing diagram so I'll help if I can. You say hooking up the jumper cables- to what? If it's to the terminals at the battery, look for bad or corrouded connections. Something I've found out the hard way too is that all of the electrical draw, (ign, headlights, PTO clutch) goes through the ignition switch, it tends to over heat the bat terminal on the ignition switch to where the connection becomes a little loose and now it won't carry the load to operate the starter and ignition. Shine a flash light (I don't see as good as I used) at the back of the switch, if one of the terminals is overheating it melts the plug in a little too. If in doubt, pull the connector off the back of the switch and look closely at the back of the switch. If you're jumping straight to the starter from the battery, are you're clutch pedal switch & seat switch working? They are pass through switchs, if working you should get 12 volt on both terminals. I ran over a stiff weed stalk a while back and it got up in there and knocked the wires off of the clutch switch. Had me scratching my head for a minute when all of a sudden it wouldn't crank over.
 

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Discussion Starter · #3 ·
We are jumping at the battery, I never really tought about the switch. I checked the battery cables for continunity and they were good but I haven't really looked at the switch. After we put the carb back on it ran fine now this!!!:banghead3 Well we'll either figure it out or blow it up......no we'll get it fixed.....
 

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When replaceing my ignition switch because of that burnt terminal I also cured the problem by useing relays on the PTO clutch and lights. I should have mentioned earlier that the solenoid feed wire goes through the PTO switch too. One side of that switch can go bad(start) and the other side(PTO) still work. Had that happen on my ole 1855. My 1650 did just like what you're describeing, cranked fine and then all of sudden not. The connection gets so bad it won't let enough amps get through to trigger the soleniod. That circuit goes through three switchs between the ignition switch and the starter solenoid. Useing the relays took all that draw off of the ignition switch, I used the factory circuit breaker for my power source on the relays. There's a sticky on here about wireing those relays ( available at most auto parts stores).
 

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Discussion Starter · #6 · (Edited)
Well today I just put a new switch in and it did the same thing, I also swapped a solenoid in and it didn't change anything at all. :banghead3. So butchs_hobby did you have to buy a new PTO switch or is there a way to check it to see if it's working? Also it will start if we jump it but as soon as we take the jumper cables off it dies. If it was a car I would think it was the alternator.
 

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We are jumping at the battery.....
If you are jumping at the battery and it starts then all the switches and solenoid would be good wouldn't they? If checking for power at the cables with a volt meter, you can have readable voltage, but not enough connection when a lot of amps are trying to be pulled from the battery. If you can jump it at the battery then the battery or the cable ends have to be the problem.
 

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Discussion Starter · #8 ·
The cables and the ends are good......I checked for continuity on them. I suppose the battery could have a short under load....I had it explained to me that there is a short somewhere in the system and that the extra volts from the jump is bridging the gap.
 

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Discussion Starter · #11 ·
You know I checked the cables, but I didn't check to see if anything is coming out the otheer side of the solenoid. Whats the chances of 2 solenoids being bad? If the safety's were bad would it start with a jump? Plus I'm not real sure this thing has any safety's on it.
 

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check the voltage at the cables, then check the voltage in the same place while trying to start it. I cant help but think that the problem is before the solenoid because the only thing you are doing is jumping at the battery. the solenoid, ignition and safety switches are good or the jump would not help at all. BUT there is a difference between a good connection for a volt meter and a good connection for high current draw
 

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You've stated twice that you checked for continuity at the battery cables, but you haven't said that you removed the cables, checked for corrosion and ensured a good clean connection. Did you check ?

Bob :rauch10:
 

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I think that MF 10GT has it right, don't assume just because you have good continuity that the cables can handle a high current draw.
 

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From what I can tell the clamping of the jumpers plus a good battery starts it so somewhere battery or terminal at battery is not good enough.
 

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Discussion Starter · #18 ·
Well I learned something today continunity does NOT mean that the battery cable is good. We took the side panels off and I found a wire that had been spliced but not very good. I fixed it and started looking over the wires again and found a cut in the cable from the solenoid to the started. I replaced it and it fired up 3 out of 3 times. So MF10GT you were right, but I want to think everybody for the help....Now I just got a few other things to fix!!
 
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