HELP!!! Electrical problems.

So I am waiting for another TCI to arrive.
If I by pass the safety relay will that remove the side stand from the circuit as well?
I'm thinking to remove all surrounding electrical circuits, and see will it work. If everything starts to heat up again, then obviously something from ignition circuit is faulty

 

So did you have a chance to check out the side stand relay and pick-up coils as suggested?

Bypassing the safety relay will not remove the side stand from the circuit. All the associated wiring is still in place so when the side stand is raised and lowered and the switch actuated it will still either apply ground or remove ground to the L/Y wire.

The side stand relay can be removed for testing purposes to eliminate that portion of the safety circuit. With the side stand relay removed and ground no longer applied to the TCI enable / disable terminal (B/W wire) the TCI will always be enabled.

Before connecting another TCI I would also suggest checking the voltages on the TCI mating connectors to make sure they appear normal.
4 pin connector:
R/W power to TCI so approx. 12V
B is ground so should be zero
O for one ignition coil primary should be approx. 12V
Gr for the other coil primary should be approx. 12V

6 pin connector:
There should be no voltage present on any of the wires

 

Ahhhhh... Finally.. I received the TCI. Anyway I gave the bike to a man with bit more knowledge. His conclusion was that the wires from pick up coils caused short by touching the frame. Well the wires are old, there is some splits in them. MAYBE somehow they touched the frame. Could that be the reason for TCI failure?
I checked everything as suggested before plugging the TCI. Well everything seems to be good enough, so I plugged the TCI. Nothing is heating, good healthy spark (didn't even expect such a good spark)

 

Good to hear all appears better and hope it stays that way.

Was this detected by actually checking continuity to ground and noting a problem? Or, was it just speculation after noting the condition of the wires?

This is a tough one to answer... I am not aware of any schematic diagram that exists on the TCI, so without that I can't say for sure one way or the other. I could only speculate that the TCI biases the pick-up coils in such a way that grounding the pick-up wires might cause some damage. The pulse from the pick-up coils per SQL Guy can be 100 volts peak to peak, so be sure to take care of those wires and verify they are properly insulated from ground. If they didn't cause the problem, they could certainly contribute to a poor running bike.

Have you started and ridden the bike? I would be very methodical about the order of things on the first run, just in case a particular event causes a repeat of the condition.

 

Where did you get the TCI? New, used, rebuilt, aftermarket?

 

If you're getting sparks flying, that would seem to indicate you have a pretty good short somewhere--- you may have fried the tci too

 

Oops.... Didn't realize that I was still on page 2---- just saw page 3...... Carry on

 

Used, from ebay

 

I think it was more speculation than fact about the wires.
I haven't start the bike yet. Just putted electrical part back. Tomorrow exhaust goes on and the try to START. Any advises on how to prevent any disaster?

 

My suggestion would be after assembly is to do the voltage and continuity checks on the TCI mating connectors again before connecting the new TCI. Just make sure no strange voltages or unusual resistance readings are noted, particularly resistance to ground. For the voltage checks, exercise the starter cutoff relay and side stand relay by taking the bike in and out of neutral, pulling the clutch in, and raising and lowering the side stand. With the TCI still disconnected, verify the you can bump the starter;
first in neutral, then in gear with the side stand up and clutch pulled in.

And, back to your original problem of the diode block overheating, make sure it is cool to the touch... hopefully you have a new replacement. If any of the conditions don't check out then don't connect the new TCI until the problem is solved.

 

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.