Condensor Testing

OT, but this does relate to my 1952 8N as well.

I have been holding a 1977 Sears SS/16 Twin-Garden Tractor in my barn for my wife's cousin who lost his "Free" from a friend storage locker seven years ago. I have not touched the tractor, other than push it from time to time to clean around it. The battery was long dead and the gas tank had rusted up inside.

He told me he drove the tractor into the storage locker 12 years ago and it was running fine at the time. Two years ago he decided too much time had past and he ask me if I wanted to just keep it, and I said yes.

Last year another friend was visiting and he saw the Sears tractor and said he had two old Sears SS/16 tractors that belong to his father, but they were in such bad shape he was going to take them both to a junk yard for scrap metal. He ask me if I wanted both of them and I said yes again. He went back home and loaded them both on his trailer and brought them to me.

All three have been sitting side by side in the barn for 12 months, but this week I started to see what I could do to make one or two good tractors out of three.

This week I have cleaned the gas tank, replaced the fuel line, plugs and plug wires, stole the double coil from the other, and tonight after hours of servicing I tried to start the first one.

I have everything working except a good fire at the plugs. I had fire for a second at the points, but it went dead.

I have the condensor out on my table and I need a way to test it. I found a test video on Youtube but my condensor acts a little different.

My Fluke meter reading on ohms goes up to 29.00, and drains the measure down to zero on DC volts.

My question is how do you test the same type condensor on a Ford 8N like mine. I have changed the ignition several times on my 8N, not because of a problem, I do it every few years just to keep it new and running, but I've never tested the old parts. I keep the old points and condensors just in case, but now I want to know how to test a condensor.

Bishop..........You don't test condensers...or...capacitors with DC volts. The OHM meter is weapon...er...tool of choice. Ohm meters are kinda trick SOBs. They provide a low voltage (1.5v battery) and a HI voltage (9v typically) to operate the voltmeter electronics.

First thing ya gotta due, is "calibrate" the ohm meter by touching the 2-leads together. You should gitt "zero" ohms on yer meter. Ennythang else requires a NEW 1.5-volt battery. The 9-volt battery last a L-O-N-G time.

The typical capacitor/condenser is an "oil-filled" device where the 2-foils are separated by oily insulator (paper-plastic).

When you touch the ohm meter leads to the capacitor leads the foils will SUCK the electrons outta the 1.5-volt battery and the electronic meter will kinda follow the electrons racing to fill the foil. Iff'n the condenser is BAD, ...ie... shorted, the electrons will continue to try and fill the foils just like you calibrated the test leads.

Now iff'n the condenser is GOOD, the foils will fill-up with electrons ...ie... volts and yer voltmeter will sweep upwards towards max volts (1.5v) 'cept you don't read volts, you read resistance in OHMS. (its been calibrated at the factory)

Now REVERSE yer leads and watch the meter. It should INSTANTLY go to ZERO and the start sweeping upwards again. Iff'n it don't, you gotta BAD/LEAKY capacitor.

BTW, most ignition capacitors are rated about 2.2 mfd (micro-farad) and about 100-volts. So just like the points, you don't haffta worry about 6-or-12 volts.

I've always been semi-amused that every time you but points, a new condenser is included. Condensers seldom go BAD but they are SOB's for the novice shadetree mechanic to diagnose. As you found out.

As an aside, CAUTION with digital voltmeters and running tractor engines. Electrical NOISE from the sparkplugs will drive the digital voltmeter CRAZY. Old fashioned needle voltmeters are semi-immune to the NOISE........Dell, former CALIBRATION engineer

yup. reading of low to high ohms.

short leads and do it again.

low to high.

I have a good tester for coils and condensers. If you care to send them I will test them for you. E-mail is open.

Unless you have a good, high impedance analog meter, don't try testing an ignition capacitor with a meter.

Just buy a new one if unsure.

Dean

I have found new ones that are bad(leaky) too. I won't put in a condenser without testing it first.