Club Triumph

My Triumph 2000mk2 broke down today .....

She has been driving like a dream and then dead 

She wouldnt run nor start. I did manage to get to sort of start but she ran so badly.

The spark was very weak and coil very hot (Maybe the original 1969 coil).

I left the car for an hour but still woundnt start.

So Mr RAC called and he was lost.

No shops open so no other coil to test with.

He said maybe the coil shorted out and took down the condenser with it.

He was trying to bridge it but still nothing. So 5 hours later back home with a dead Triumph.

I need to order a coil now and condenser.

Does my coil need a ballast resistor? I think my coil has a ballast resistor next to it?

Maybe I will keep a spare coil and points and condenser in the car at all times.

Ballast resistors usually look like this and mount on or near the coil. I take it the RAC man tested the resistance of the coil and condemmed it?

Yes thats what I have next to my coil.

Thanks for the photo.

He ran some tests but said his tester was not the best lol (Good old RAC ).

with a simple multimeter its pretty easy to carry out a basic test on a coil as the primary side (small terminals on the top) should have about the same resistance as the ballast resistor.....

The RAC chap said that the resister side it was 12v but only 7.9v at the coil.

well thats not too far wrong as in normal running half of the cars voltage should be across the resistor and the other half for the coil. However when youre starting the engine the power required to turn the starter motor causes the battery voltage to drop a lot so the ballast resistor is bypassed to ensure there still a good voltage at the coil.

So why the weak to know spark? And coil being so hot?

Ohms across +/- is 2.7 and from centre coil lead out to + is 6.5 coil on kitchen side so nothing connected to it.

Ok the primary resistance sounds good at 2.7ohms but the secondary side from HT lead connector to the coil case should be much higher at 5000 - 20000 ohms  

It is 6.58 so isnt that 6058 ohms?

Also the resistance reading between primary and secondary side (+ve terminal to casing) should be very high or open circuit....

6.58 depends on what scale youve got the multimeter set. Have you changed scales between the 2.7 and 6.58 readings?

6.58 is set at 20k and 2.7 is set at 200ohms

well those readings are looking pretty good and the last one for primary to casing?

The last one is + too -  6.58

So it seems maybe the coil is ok?

And should it be so hot to almost burn your hand?

And why no spark or at best weak intermittent spark?

ahhh so HT to casing and +ve to casing have the same reading? That sounds like a short between the primary and secondary circuits somewhere near the HT lead connection so that when testing +ve to casing your effectively measuring the resistance of the whole of the secondary winding through to its connection to the casing.....

you should also get a low reading from +ve to HT....

Sorry I dont understand how to test HT to casing.

Ohms across +/- is 2.7 

And from centre coil lead out (HT) to + is 6.5 The coil is on kitchen side so nothing connected to it.

HT to casing is just one test lead connected to the HT lead connection and the other touching the metal casing of the coil. The internals are just two separate windings, one connected across +ve and -ve and the other HT to casing....

Ok sorry I thought you tested it by putting one prob in the HT output and the other prob on the -ve.

So I have just put the prob into the HT prob and the other prob touching the outer metal casing.

With it still set in ohms it didnt show any reading.

no sorry I always thought the casing formed part of the HT circuit but it appears not as both the primary and secondary windings are connected together inside the -ve terminal. You have measured everything correctly and the readings look good although unfortunately this doesnt guarantee the coil because the winding insulation can break down in operation. For the cost of a coil I think its worth getting a new one and at the worst you'll then have a spare - definitely let us know what the outcome is!