Ignition Switch smoking at the resistor

[dvtw79]

Just got a 70D with the pony motor on 6V. It hasn't ran in about 25 years, but
both motors are now running. Whoo-hoo!

First time trying to start the pony, I turned the switch to the "on" position prior to
cranking the pony and the little resistor on the back of the old switch would smoke and
get red hot with the switch turned on.

Here's my question...I installed a new switch, and it is doing the same thing. The
resistor on the back of the switches (old and new) starts smoking and getting red hot.

Is this normal??

 

[Bob Harvey]

Pretty much. It is a resistor, hence converting electrons to heat to reduce the 'flow'. The smoke may go away over time - dirt, oil or packing grease may be the current (no pun intended) source. HTH

 

[buckeye al]

Getting hot enough to burn your fingers or make oil on it smoke especially on its first use? Ya maybe.

RED HOT like a toaster element? NO! Something is wrong some place and it is passing too much current if it's getting red hot!

Make sure no "other appliances" are powered by these posts of the switch. Those posts should ONLY power the cranking engine distributor, nothing else. Check the bypass wire from the cranking engine starter switch to the distributor to make sure it is functioning properly and NOT faulting to the frame or to the cranking engine's starter. Check the bypass switch operation in the cranking engine's starter switch too.

That little guy should not glow with heat!

 

[Bob]

Resistors do their job of dropping voltage/limiting current by making HEAT.

That we can all understand.

But WHY are you switching the pony's ignition "on" and dilly-dallying around looking at the ballast resistor?

Flip the switch to "ON", start the pony, start the big engine, then shut off the ignition to the pony.

All that can be done in less than a half of a minute, way BEFORE the ballast resistor has time to heat up and worry you!

 

[ET]

You don't have 12 volts hooked to it do you? That's a bad thing for pony motor ignitions.

 

[dvtw79]

No sir, it's an Optima red top 6V battery.

 

[dvtw79]

The first time I started the pony over, I noticed smoke coming from under the dash. The hood was off and I could see smoke and smell something burning. Naturally, that alarmed me given the fact this thing has sat in a barn for 25 years idle and not knowing the condition of the wiring, etc. I was standing and leaning over the steering wheel so the smoke was wafting right up into my face.

So, that's why I started to investigate. Seems to me it is getting too hot. At any rate, thanks to comments like yours, I will do my best not to leave that switch on any longer than necessary and get to it!

 

[dvtw79]

Buckeye al, I have one suspicion that I do need to check based on your comment. The wire than runs from the ignition switch down to the cranking engine is new. The old one was in rough shape with lots of "naked spots". The wire that then runs from the post on the cranking engine starter switch to the distributor is also new.

The starter switch was bad and we had to buy a new switch which corrected the starter problem. My local tractor shop didn't have one with a side post on it, so we bought the new swtich and drilled it and put the old side post w/old insulator and everything else inside the new switch. I'm wondering if I have a short through that side post to the starter maybe somehow. The insulator was old and the copper tab inside the switch may be touching the housing.

I put a VOM from the wire/side post on that switch to the starter casing and it was showing .5 Ohms. That would seem to indicate that the post is grounded and I don't think that should be the case. Maybe that is the issue?

I may order a new starter switch with the side post terminal and see what that does.

 

[John T]

Its been years since I owned and worked on those, but best I recall (NO Warranty), that ignition ballast resistor reduces the 6 battery volts down to around 4.5 for the Pony's Wico Distributor Ignition. I think some gents who use the new improved pony coils do away with (by pass) that ballast and just supply battery voltage to the coils. I agree a ballast, especially if old or dirty or dust or oil covered gets pretty hot and can smoke, but NOT so hot it turns glowing red.

John T

 

[WeirdDeere]

I was running my ponies thru the resistor, but I switched one to full six trying to trouble shoot and it ran SO much better, I'm definitely in the camp of no more resistors for the pony motors.

Brandon

 

[old]

Does it say red hot when the pony is running?? Bet it cools some when running. Also bet you if you where to spin that pony over just enough that the points are open that resister will not be red hot but then that is because the curcuit is open and with the points closed it is a closed circuit and the resister is taking full battery voltage so yep it will get hot

 

[dvtw79]

I was able to tinker a little yesterday on the 70. I turned the switch on and immediately proceeded to fire up the pony and got her running and all seemed to be well. With the engine running, the resistor never really got hot. Guess that is normal for the resistor to heat up with the points closed and the engine not running.

On another note, ran about a tank of gas through the pony and the carb must be chugged up, because I had to run it on near full choke to keep it going. The tank and line are clean, so I suspect the carb is dirty. Also found a MAJOR oil leak coming from somewhere on the pony. Not sure where. I may save that for another thread...

 

[old]

Having to choke it to keep it running can be a carb problem but can also be a spark problem. I would check the spark and make sure it is a good blue/white in color and that it will jump a 1/4 inch gap or more. Next I would pull the carb drain plug if is has one and let gas flow for a few minutes. It should flow fast enough to fill a pint jar in less then 3 minutes.

 

[buckeye al]

With the wire between the starter switch side post and the distributor post disconnected, and the starter in the NOT running position, that post should measure as an OPEN!

This wire and that tab inside the starter switch is supposed to BYPASS the resistor on the ignition switch putting full battery voltage to the distributor for extra hot spark when the starter is cranking the starting engine.

If the little tab inside is touching the post of the starter (it should not be) it's trying to run the starter whenever the ignition is switched on. If it's touching the frame of the switch it is at least partly shorting out the distributor. Either condition would definitely pull extra amps trough the ignition resistor on the switch making it get extra toasty!