HELP!!! Electrical problems.

and also check that your voltage doesn't climb past 14.5v....otherwise you'll be looking for a new regulator too.

 

Well, I failed to start the bike today. Battery went flat. Plus leaky carb. Anyway the voltages was ok at TCI, the pick up coils resistance was good, spark good. BUT, no matter what I can only run the stater with clutch puled in. No matter is it in neutral or side stand up/down. As much as I remember if the bike is in neutral it should start right?

 

Completely academic, but faults in the pickups won't damage the TCI.

Shorted across, shorted to ground, open... Shouldn't cause any lasting effects inside the box.

 

That is a good thought. Not sure you ever had the bike running since the issues started, but just in case do the test once the preliminary checks mentioned earlier are completed.

Put a voltmeter across the battery once you do get it running to check the Rec/Reg output. Slowly raise the RPM making sure the voltage does not exceed the 14.5 +/- .3 as Dave suggested. It should reach 14.5 V at around 2K RPM, and should not continue to climb above 14.8 V as the RPM is raised above 2K.

Yes, the starter should engage in neutral regardless of the condition of the clutch or side stand... OR in gear AND the side stand up AND the clutch pulled in. Do you have a neutral light illuminated? Starter should not engage with the clutch pulled in while in gear and the side stand down.

Thanks, that is good information to know. I did not want to make that assumption based on my lack of knowledge of the particular component hookup inside the TCI to the pick-up coils. I am not aware of any electrical schematic diagram for the TCI that is available for viewing. And, I sure did not want to try shorting them to ground on a functioning TCI. Also, I would be very interested and thankful for the basis of that statement. Are you speaking from an actual experience or have you evaluated the circuitry inside the TCI through a bit of reverse engineering?

 

opps

 

I have evaluated the circuitry inside through reverse engineering.

And beyond that, the pickup modules themselves are simply coils to ground. One side of each coil is used as the input to the TCI and the other sides of the coils are connected to ground. When there's no signal, it's like the input pins are pretty much shorted to ground through the coil anyway.

 

Thanks for the reply, but I would have to respectably disagree with that analysis when the coil resistance on the high side places them 650 ohms above ground. I would agree that it is likely no damage would occur on the basis of the circuit in question is input, which typically employs a design that is not subject to damage from ground.

 

the TCI expects to see 3 ohms, it's designed to pass the current drawn by a 3 ohm load. more resistance will draw less current but 0 ohms (a short)will draw all current available and do bad things to the output components

 

Why would you? You've not been inside the box.

Yes, the pickup coil is approx 650 ohms to ground. However, there's a resistor inside the TCI box that is in series with that pickup and that resistor value is about ten times as large as the pickup resistance. So you've got about 6200 Ohms to ground with the pickup properly in series and about 5600 Ohms with the pickup input shorted straight to ground.

In other words, as far as the TCI input pin is concerned, there's pretty much no difference whether the pickup has 650 Ohms or zero. You can think about it this way... It's the difference between 90% and 100%. The pickup coil resistance makes up that last 10%.

Like I said... Academic.

 

Polock, We're talking about the input side, not the output driver side.

In other words, we're talking about the pickup coils, not the ignition coils.