vac dead

kenbob · Mar 17, 2020

I have had my vac for over 2 years. It has always worked faithfully lately. I put a spark plug tester in line. WHen the tractor would fire the light would light but that wasn't very often. I put new points and condenser in. Now it does not fire at all. THe previous owner had put in an 8v farmall battery. That made it start easy, and pretty much eliminated any overcharging by the 6v generator. I see where 12v can cook a 6v coil. Can I assume that over 2 years of use the same has happened? I know there has been a problem with new condensers, but it seems it should have fired for a little while before burning the points.
Thanks for any advice.

old · Mar 17, 2020

I'd start by putting the old condenser back in. I have not changed a condenser in well over a decade in any of my tractors. If that does not do it then pull the cap off and turn the ignition on and carefully open and close the points when you do that you should see a small spark or you can pull the ignition side wire off the coil and have the cap off and with the points closed touch the wire to the coil post and then back off. You should see a small spark when you do that. Then turn the engine till the points are open and do the same touch the wire to the coil test. If you have a spark then you have a short either in the insulator going into the side of the Distributor or at the wire from the condenser at the points

Bob · Mar 17, 2020

First of all, older condensers SELDOM fail, and replacing a "good" one with one from "The Land of Almost Right" is a step backwards.

Other likely causes of having NO spark now would be points with a non-conductive film on them, or possibly you mucked something up where the point spring attaches and created either a "short" or an "open" in that area.

Connect a non-powered test light between the primary terminal on the distributor and chassis ground, turn on the ignition, and crank the engine, and post back with what you observe the light doing.

(In another recent thread, a poster had the same problem, and solved it when he found the rotor in his shirt pocket the next morning!)

kenbob · Mar 17, 2020

Ha! I have done similar by forgetting to put the rotor on. Thanks for the tip.Is there a special sequence for attaching the point spring and condenser? THe old condenser was already from the land of almost right.

kenbob · Mar 17, 2020

There may be my problem. THe old condenser was already a chinese one and the points looked burned. AND the new condenser the wire was only clamped to the U shaped mounting flange (not soldered or bonded) and that was loose! I reclamped it and it is tight, but not bonded to the U like the old one was. I would like to find a NOS condenser but not sure if there are any of those out there

old · Mar 17, 2020

There out there but people like me are not likely to let them go lol.

oldproudvet · Mar 17, 2020

The only way to pry stuff out of guys like myself, is with a good swap (not your first born).............. That's how I get stuff now days. begging sometimes works if a guy has stuff a dozen deep, otherwise you'll just have to come to our auction....... Larry

kenbob · Mar 17, 2020

I did the test as you said. I first made sure the test light worked by testing it to the battery so knew I had a good ground. I am not up on my tractor words, but I think by primary wire you mean the fat one in the center. No light no nothing. There is power to the other terminal on the distributor when the switch is on. As for as Old told me, the points do arc when turning the tractor over. With the points closed and the wire off the coil it does spark when you touch it. With the points open and the wire touched to the coil post no spark.

Bob · Mar 17, 2020

(quoted from post at 18:01:25 03/17/20) I did the test as you said. I first made sure the test light worked by testing it to the battery so knew I had a good ground. I am not up on my tractor words, but I think by primary wire you mean the fat one in the center. No light no nothing. There is power to the other terminal on the distributor when the switch is on. As for as Old told me, the points do arc when turning the tractor over. With the points closed and the wire off the coil it does spark when you touch it. With the points open and the wire touched to the coil post no spark.

"I think by primary wire you mean the fat one in the center."

Nope, the primary wire connects to the threaded stud that passes through the distributor "body".

kenbob · Mar 17, 2020

I didnt test that one when it was turning over but with the switch on there was power there.

old · Mar 17, 2020

I've seen a bad cap or bad rotor do what your seeing. That test says the points are working as they should be so only thing left is the cap or rotor or even a bad coil

kenbob · Mar 17, 2020

THe cap looks good (3 years old) new rotor...I am thinking coil cooked from 8v battery

old · Mar 17, 2020

A cap can look good but still be bad. One way to test that while not fun is a sure way to know. Grab the cap and try to start it. If you jump 5 feet the cap is bad. I learned that one the hard way ona1971 GMC pickup

kenbob · Mar 17, 2020

So Bob are there further tests I can do since the primary has juice when the ignition is on?

mEl · Mar 17, 2020

If you have power on the distributor connection when the points are closed your points are not making contact or are not adjusted properly, the points should be set at.020 thou with the pints rub block up on a lobe on the points cam.

kenbob · Mar 18, 2020

points are at .20 and they arc when the starter is turning over.

kenbob · Mar 18, 2020

Maybe I will have the wife grab onto the cap while I turn it over.

8NHENRY · Mar 18, 2020

Make sure you let us know how that turns out 8)

mEl · Mar 18, 2020

Is the system still using the 8 V battery? Does it still have the generator on it? It sounds to me like you may have a bad coil but the condenser is still suspect, without being there and seeing what's going on maybe the coil is weak. Echlin or Standard are good names in the electrical brands to get good quality stuff, Sorry to say but the Tisco brand condensers have been junk , I tried two in a row on the same job and they were both bad, ended up using the old one over. The reason I am asking about the voltage is the coil must be changed or a resistor added if the 6 volt coil is used on a 12 V system, with the points closed use a screwdriver to open them and hold the coil wire about 1/4 inch away from the block and see what happens, it should have a healthy blue spark, Voltage measurements at the coil on the opposite side from the distributor wire would be helpful checked both static and also when turning it over. Does it have spark with the metal points cover off?

kenbob · Mar 18, 2020

power to the primary on the distributor when key is on. Points arc when turned over. That 8v battery has been in it since before i got it. It has 6v generator. It
sure started good in the past. I didn't know over voltage could cook the coil but maybe over 3 years that has happened. I am going to put on a new coil and get a 6v
battery.

kenbob · Mar 18, 2020

Regarding condenser: I am trying a new one. It would seem if that was the issue it would fire for a minute after being turned on till the points burned but I got not one
pop out of it.

mEl · Mar 18, 2020

The primary function of the condenser is to absorb the current flow as it can no longer has a path to ground once the points open, so the voltage rushes into the condenser and then as the voltage discharges out of the condenser it vastly intensifies the spark, saving the points from burning is only one of the functions of the condenser.

vac dead

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Similar threads