How to test a Condenser or Capacitor

I usually change my condenser at the same time as my points but here is a test to see if it's faulty or not. A bad condenser can cause misfire and burning of the points. Motors won't run properly without a good condenser. This is a basic test for beginners. Thanks to my friend "A" for his advice

[orman]

Good simple explanation and vid. I will make one comment which is about changing condensers each time you change points. As VW beetle owner I can testify the days of tossing a good, old one are over. They no longer make decent condensers. They fail frequently with minimal use. If you have a good old one, keep it. Buying a new (especially Bosch) condenser is like rolling the dice

[km-gilw]

Had an 850 British Leyland Mini in 1970 going on a very long trip North and after half way pulled into a wrecking / recycler yard and said everything had been checked and it was still misfiring. he listened for a minute and oh that's a condenser. He charged me 50 cents (believe it or not) and that was the end of the condenser problem. It's like a ballast in a Fluro Light, acting as a current limiter for the high voltage, that's my limited explanation of it. Thanks for the good clear video.

[arnoldgregory]

I am retired now so I scaled my activies break. I have learned a great.deal in the last few weeks. I was a diesel mechanic for 20 years.thanks for posting it helps a great deal

[Rnmhart]

You had some questions on the bad capacitor when it did not go above 4 OHMS. The Condenser was partially shorted out.
Checking the Condenser:
1)Turn meter to 20 Ohms. 2)Put negative lead two wire coming out of the Condenser. 3)While watching the meter put the positive lead to the casing.
IF the Meter reads /5M Ohms 10M Ohms 15M Ohms 20M Ohms = Good “Yay woo “
IF the Meter reads / 5M Ohms, then 20M Ohms or straight to 20M Ohms = BAD low Dielectric.
IF the Meter does not go above 12M ohms = BAD partial short.
IF the Meter does not change from 0 ohms = BAD 100% Shorted

[JR-bjuf]

Back in the old days we used to replace points and condenser because they came in a set but the truth is condensers hardly ever went bad. The condenser is there to act as a voltage shock absorber or to keep the the current from surging or coasting across the points gap. Symptoms of a bad condenser are a bright flash at the points or pitted and burned points. Most of the reason to change the points was due to deterioration and wear on the rubbing block against the can.

[snhongo]

Thank you very much for the explanation on how the condenser is connected when its in the car, I understood the diagram much easier, I never really knew exactly what was going on there.

[Swampwild]

Thanks . You didn’t point out a bad one. Also the explanation of the electric flow I think isn’t how most other old engines work. Strange about going back from condenser to coil.

[irfaanxlcr]

Thanks for your detailed explanation and video. I'm having a problem with my 1978 Honda cb125s . I needed to know how to check the condenser and you just showed me how. Thanks once again. Very good . Have a nice day.

[peroduanippa]

Good vid and now I understand the incident @ at 4:15 which another youtuber pointed out, don't touch it with your hand. It also make me want a Renault 4.

[andreww]

Hi there! I think I'm the "A", who advised you about condensers on the Renault 4 Forum! When one tests condensers it's best to wear thin rubber gloves, as the moisture in one's fingers and hands cause current to leak & affect the meter readings. While testing the (I think) third one your fingers were on both the lead and the condenser body simultaneously, which may have caused you to condemn a condenser to an early grave!

[robertsapp]

Nice, simple explanation! Thanks for taking the time to make the video, saving me time!

[cheewurz]

Sir...when doing those types of Tests with your Multimeter, try Not having One Hand Touching One Lead and the Other Hand Touching the Other Lead at the Same Time as the Meter may/will/can Read the Resistance through your Body and/or your Part being Tested giving you an Erroneous Reading...One/Either Hand is Okay. If your Meter Reads the Same when Neither Probes are Touching Anything or the Part being Tested...the Part is OPEN, sometimes that is what you want and sometimes it is not what you want...depends on the Part you are Testing -- for a Capacitor/Condenser it would be BAD/FAILED/NO GOOD. If your Meter Reads the Same when you touch Both Leads Together or the Part being Tested...the Part is SHORTED, sometimes that is what you want and sometimes it is not what you want...depends on the Part you are Testing -- for a Capacitor/Condenser it would be BAD/FAILED/NO GOOD. If you Test the Capacitor/Condenser with your Meter the Numbers on the Display should go UP and if you Reverse the Leads they should go DOWN -- that Capacitor/Condenser SHOULD be GOOD as it is Charging and Discharging. This NOT a 100% Test for Capacitors/Condensers though as this Test does not Check Internal Leakage, Resistance, etc. You would need Other Test Equipment. Condensers are Very Cheap, that's why most guys Replace the Condenser.

[vidvidbiker]

The condenser is not linked in anyway to the secondary coil winding or generating the spark from that winding. Its purpose is to act as a store for current when the points open. This reduces arching across the points and the points then burning out. Misfiring maybe caused by the points being pitted or burnt out (as this will impact on the timing). Burning out points maybe caused by a dodgy condenser or breakdown of the coil reducing resisting (which also causes arching at the points). Thanks for posting re how to test a condrnsor though!

[ralphharris]

Excellent demo, straight to the point yet explaining every aspect I would need to know.

[rickhjortsberg]

Excellent presentation on testing. Well done sir.

[AaronRiegel]

Nice video. I always would just replace them without testing this is nice info

[Tree-feller]

Thanks for posting your video, just what I needed to learn right now.

[chuckmaddison]

A couple of other hints of poor capacitor. The motor may start but won't rev and the points if the negative has an excessive loss of metal, then the capacitor is low on capacitance.
If it's Lucas, change every time and carry a spare.
Best option fit electronic ignition.

[dlc]

Will this keep the spark plugs from getting voltage?. Engine turns over no spark

[fiffe]

Thanks for the vid. Would a bad consider cause the voltage after the consider to be lower than the voltage before the consider.