Volts going to coils

[DavesXS]

Originally posted by 81xsproject
my '81 doesn't use resistors in the first place.

Come to think of it...Why would a resistor be there any way. Thats a good ez free mod. Remove resistor mod. A quick step up going into the coils.
The box steps up much more so the resistor would hurt the performance. Probably an emissions thing.

[81xsproject]

No, it needs to be there unless you go to different coils. Otherwise, IIRC, it can damage the 2H7 iggy. Other than the built in timing curve, that is one of the differences in the 4RO iggy. It was made to work with different coils and no resistor. So the no resistor mod only works if you also change coils to...

[Crazcnuk]

Trying to follow this, after all is said and done what should the voltages be at the TCI connector?

I know what it says in the manual, ie; 12 volts for most, and 6 volts on the black/white.

When I checked mine tonight, with the key off, all the 12 volt ones were 10.85 volts, and the 6 volt black/white was 6.38 volts.

The battery was at 11.8v.

[DavesXS]

Originally posted by Crazcnuk
Trying to follow this, after all is said and done what should the voltages be at the TCI connector?

I know what it says in the manual, ie; 12 volts for most, and 6 volts on the black/white.

When I checked mine tonight, with the key off, all the 12 volt ones were 10.85 volts, and the 6 volt black/white was 6.38 volts.

The battery was at 11.8v.

Originally posted by DavesXS


Can some one who's bike fires great check the volts coming from the ignition control unit gray and orange wires on the end?

Thank you for taking the time to check your volts. That helps tell me what it really should be now. Not what the book says it should be brand new.

[DavesXS]

Originally posted by 81xsproject
No, it needs to be there unless you go to different coils. Otherwise, IIRC, it can damage the 2H7 iggy. Other than the built in timing curve, that is one of the differences in the 4RO iggy. It was made to work with different coils and no resistor. So the no resistor mod only works if you also change coils to...

I'm going to install the msd's

Its too late but maybe admin can edit my post and take out the remove resistor mod part so new guys don't try it with out reading further to see they'll fry there coils

[randy]

In reality, the TCI does not put out voltage to the coils. The coils are fed +12V through the resistor, dropping it to (now don't crucify me for this) 9V or 10V.

The TCI grounds the Gray / Orange from the coils to complete the circuit. As the pickups send their signals to the TCI, the TCI breaks the circuit to fire the coils.

[DavesXS]

Ok swapped coils. No more resistor. And double checked connections.
The wires running to feed the coils Y off one single wire. So its not the supply.
It did it again when I first started it. Gray wire had 2 volts and not firing. It quickly corrected and both are at 10-11 volts.

I think what ever controls the gray wire is going out in side the TCI. Maybe moister got in or something.

[randy]

Dave,

If you searched my web page, you may have seen the photo of the pins inside the TCI. If you haven't, click on my www above.

You won't even have to remove the box from the bike, just unscrew the cover and solder the double row of pins near the connectors. Use a small pencil-type soldering iron, not the monster one with the headlights in it! Use new solder, just re-heating won't work, the old solder is corroded.

Do not apply too much solder as to bridge between pins or you'll cause more trouble than what you already have. Good luck.

[DavesXS]

Originally posted by randy
Dave,

If you searched my web page, you may have seen the photo of the pins inside the TCI. If you haven't, click on my www above.

You won't even have to remove the box from the bike, just unscrew the cover and solder the double row of pins near the connectors. Use a small pencil-type soldering iron, not the monster one with the headlights in it! Use new solder, just re-heating won't work, the old solder is corroded.

Do not apply too much solder as to bridge between pins or you'll cause more trouble than what you already have. Good luck.

I don't see a link?

I looked inside the tci and the board looks good. But I can't see the other side. Some battery acid has gotten in. Just a tiny bit, dunno when or how. Maybe when the PO had it. It looks like it could have gotten on the other side but can't tell for sure. Just trickled in the edge and burned the plastic and corroded a screw. This could be the culprit right there.

Theres only one available TCI on ebay so I'm gonna get it regardless. And I'll check for and do solder fix in the new one. Then I might go further into this one and check the other side of the board if I can.

[egsols]

I don't see a link

It's between his "pm" and "search" buttons at the top of his post.

Battery acid in the box? That can't be a good thing.

[dbeardslee]

Then I might go further into this one and check the other side of the board if I can.

I think you have to unsolder the connections that connect the board to the spade connectors to get it out and look at the other side. I agree with egsols, battery acid in the TCI doesn't sound like a good thing.

[DavesXS]

I had noticed the screw was looking corroded and that made me open it. A trickle got past the rubber seal and you can see where the trickle ran down the inside box. Don't look like it got on the board since the board don't touch the sides. But the fumes from it drying can do harm as well.

But with the new coils it runs a lot better. When there both firing


I'd have never seen that www up there if not pointed out, thanks

[randy]

Dave, even if you take the board out, there's not much you can do on the other side, you shouldn't bother.

[Crazcnuk]

"Thank you for taking the time to check your volts. That helps tell me what it really should be now. Not what the book says it should be brand new."


No problem, I am having issues that may be associated with the coils too, so I have been following your thread as well.

I know that the voltage, with the bike not running, can't be more than the battery is putting out, so I suspect that, in my system max would be the 11.8v from the battery, but that still means I am short 1 volt somewhere, unless that is normal.

[DavesXS]

Originally posted by randy
Dave, even if you take the board out, there's not much you can do on the other side, you shouldn't bother.

After looking at the pic you have on your site I came to the same conclusion. If any did get on it I'm not going to start replacing diodes and such. I'm not the electrical guru you are.

The solder on the pins look shiny and new perfectly clean every where. I didn't touch the pins though. Could be a loose pin I guess.