Testing Condensers and Coils

[gppj25]

Jusrt in the middle of sorting a few niggly ignition problems on my Traveller - 1098.

Does anybody know the best way to test a Condenser and a coil - and what are the correct resistance values etc?

Thanking you


gppj25

[PSL184]

A 12 volt coil should read about 3.5 ohms - any less and it will fail imminently. No point in testing condensors as they either work or don't work and are cheap enough so just replace.

[bmcecosse]

I agree - just throw condensers away - or use them as suppressors. Coil is indeed ~ 3 ohms for a 12 volt one (2 ohms for a 'ballast' coil) - between the two low volt terminals. I'm sure i have seen figures for expected values between each LV terminal and the HT - different for each - which is why coil connections should be reversed if swapping battery earth around. Any one know what they are ? Other test for coil of course - is it leaking oil? If so = bin.

[mogbob]

The secondary circuit test should be done with the meter set to resistance/ohms.Black lead connected to the centre post
( where the king lead going to the distributor exits ) red lead connected to the "plus".The reading should typically be around 5 ohms.
IGNITION SHOULD BE SWITCHED OFF AND ALL THE WIRING TO THE COIL DISCONNECTED before testing.Suitably lable the wires for easy re-connection.

Bob

[bmcecosse]

That's one terminal - but what resistance to the other ? They are different I believe on a good working coil. I'll try testing one later - if the rain lets up.

[mogbob]

The other test...Primary circuit...basically as already posted by your goodself.
Red lead to the plus terminal, Black lead to the negative.Meter set to resistance / ohms , orginal leads labelled and disconnected, ignition OFF.
Readings generally... Standard Coil ( No Ballast ) greater than 3 ohms ( Ballast ) 1.3 to 2 ohms
Sports Coil ( No Ballast ) 2 to 3 ohms ( Ballasted ) 0.5 to 1.2 ohms

Bob

[bmcecosse]

Yes - but the readings from each of the LV terminals - to the HT terminal are different I believe. And should be in the range of 5000 to 8000 ohms - NOT 5 ohms!! And no - it's been too cold/miserable etc to go searching in the garage for a coil !