Another Points Question

[wavehog33]

The lead wire (black/yellow) to my middle cyl points reads 11 volts with my multimeter. How come when I put my garage built timing light on that same wire and ground it on the brake pedal it will not light the bulb. When I check it on the left and right lead (black and white wires) the light lights up fine? This is with the points removed and ignition on. How can a wire read 11 volts on the meter but not light the bulb??? Thanks!!

[h2okettle]

That yellow/black wire goes to the center coil where it picks up the 12 volts from the orange wire.. You might try going to the coil and try the test again on the Bl/Y wire and see if it changes.. If it does then the wire to the points is probably bad.. If not, maybe you can try hooking one of the wires from the other cyclinder to that coil and see if does the same thing.. I lost the center cylinder fire on my GT750 once and found it to be the wire had a break in it about two inches up from the connector.. If it does get the same reading (no light) after you try a wire from another cylinder hooked to the center coil, you can try to see if the orange wire has the same reading (12volts) coming into each coil.. If all those read good it may be a bad coil..

You can test the coils by hooking your muti-meter to the orange and the bl/y wire.. You should have 4-6 ohms resistance.. If the resistance reads infinity the coil is bad..

If all three chack good you can go to the plug wire.. Remove the cap and hook one wire to the end of the plug wire and the other to the orange wire at the coil.. the resistance should be 15-25000 ohms.. If its lower the coil has a short and if higher it has on open in the coil..

Allen......... Revving to the red zone, without adult supervision....

[wavehog33]

Thanks for the response. I believe there may be a loose connection or something going on. When I went to check for continuity I clipped the red of the timing light to the yel/blk wire near points and then the black I checked on the other side of the plastic connector plug up near the harness area. I had to move the yel/blk wire around to get the probe through the insulation and the light came on. So must have a tricky wire someplace. What I mostly do not understand is how was I showing 11 volts and not getting the light to light?? If I had continuity and the volts, how does the light not light?? That just doesn't compute to me?? Rode the bike about 30 miles and everything worked awesome. Not sure when or if the problem will show itself again but I will address it at that time.

[BRP Tourer]

A bad connection can cause what you are seeing, or a broken wire. Your volt meter only takes milliamps to get a reading, the test light probably takes 1-3 amps to light the bulb. So a bad connection can allow a tiny bit of current through to register on the volt meter but not enough to light the lamp. Look at volt as pressure and amps as flow volume, and ohms as restriction to flow.