The question is, should it be a continuity where the arrows are pointing(L-B):?) [image]http://members.optusnet.com.au/mczx/temp/diag.jpg[/image]
The power transistor it's disconnected from the harness and I'm getting continuity in those points and when the ignition is on I'm getting 13V there
Electronic Answer Youre getting 13V across there when Ignition is on. I apologise if I am telling you to suck eggs but here is some help. Thats good. That means you're getting voltage accross the Collector and Emitter lines. If it was zero then you'd have a short to ground - bad. By the way if you do a cont check between those points remember to disconnect everything else in common. You have a coil in common (on the positive side too) right near there according to the diagram. With DC voltage (what your multimeter puts out for resistance checks) a coil just becomes another bit of wire and you end up with continuity. I would be more interested in finding out what you get at those points with the tansistor in place. Hope this helps you mate Jimmy:-Z
Thanks for your help... When transistor is connected I'm reading there 12V.I was a bit confused because when I checked it showed me that both lines were in common to ground
Some info The power transistor is a switch, which will switch ON (ie be a short across the two wires that you've pointed out) when a signal voltage is applied to the base (the wire labelled G/B). This will allow current to flow from the fuse block via the wire marked G/W, through the ignition coil primary, the via wire L through the power transistor, and to earth, via the wire marked B. The current flowing through the coil will set up a magnetic field in the coil. If the signal voltage is them removed from the base of the power transistor, it 'opens', or turns OFF, breaks the circuit, the magnetic field colapses and gets out via the coil secondary, and causes a spark to head off to the distributor. If you have a reasonable multimeter, you can either test the transistor directly by using the diode check function (used to be described in the back of a Dick Smth catalog, if you have one handy) if it has it, or by the resistance test. With the power transistor unplugged, check the resistance across the two wires that you have pointed out. It should be very high. If it is not, then the transistor has 'punched through', and it's had it. Voltage wise, with everything plugged in again, check that a signal voltage is appearing and disappearing on wire G/B while the engine is cranking, and also check that the voltage across the two leads that you are measuring is changing from 12 volts to 0 volts. Hope this helps
Thx Dave an excellent explanation:YD :YD :YD Yep, I have a pretty good multimeter and I already checked that, well it looks like everything is ok, so I have to go back to the drawing board
