need diode help!!!

After examining my wiring trying too find out why I wasn't getting 12v too my second coil, I jumped online and found a tci test procedure that involved putting 12v through the tci and wire harness. Needless to say it did way more harm than good!i now have no spark at all , my warning light , neutral light and horn have all ceased too function. I believe I may have toasted my tci box. So I start poking around hoping I just popped a fuse and found a single diode inline with the blue wire and the blue/yellow striped wire under my tank that was broken. The diode is very small and globe like in shape with only a blue stripe on it. It was encased in clear vinyl. My question is does anyone know the value of the diode and where I can get it? I will try to attach pics asap

 

It won't let me post pics from photo bucket

 

Jim, I believe you need to have 5 posts under your belt before you can post a picture. Post a couple more times.

Sorry, that's all I can offer... me n 'lectricity like

 

That diode is used in conjunction with the neutral switch to activate the side stand relay to enable the TCI. You should be able to put the side stand up to engage the relay, and hopefully spark will return. The only failure it should cause by being broken is if you put the side stand down while in neutral the bike will die, whereas is should keep running.

As well as flasher and brake lights? Signal fuse powers all of those so I would check that a bit more closely.

Care to share the link so we won't try it, or maybe it can help to see if it did damage the TCI - hopefully not.

It is a small current diode, so if you still have a Radio Shack in your area a 1 amp signal diode will easily do the job.

 

And to add this, the TCI is not going to cause loss of 12V to one coil if you are checking the R/W wire. If 12V ignition is good everywhere else except one coil, the more likely problem is the main harness where the single output of the kill switch is spliced to go multiple places - TCI, coils, side stand relay, and starter cutoff relay.

 

^^^^^^^^^^^^^ gets my vote for being the problem.
you may be able to rig a jumper wire from the good voltage wire at one coil to the other bad wire to test this problem. better to dig into the harness

better would be to splice a wire at the connector in the harness where the right control connects
just get the correct red/white wire it is real close to the coils and you would not have to cut into the harness

turn on key, turn run/kill switch to off and wire with no voltage is the one you want

 

Photobucket no longer allows posting to other sites without paying an annual fee to them.
You can upload or link photos afe five posts here, but you will want to use a different hosting site if you want to embed or link.

 

wtf?
the only reason I opened a Photobucket page was so i could post pics on a Leyland forum... obviously I haven't posted in awhile.

 

and all the photos you posted have vanashed and been replaced with a photobucket statement
open one of bigfitz53 threads his photos are no longer available

 

Do you own a very tall bus?

 

darn it!

no something kinda like this...


Not mine cause I can't link the pics.....

 

Thanks for the replies! I will let y'all know what I find!

 

Got the cluster lights and horn issue figured out. It was a connection at the fuse box. Still no spark. I have 12v at the red and white wire going into the tci but nothing coming back out. I'm still thinking it's fried.

 

Started from ground zero again. Went through and ohm checked the ignition and pickup coils. All are within spec. Then I went hunting for voltage. Found voltage at both coil plugs but, I noticed on the wiring that feeds the right ign coil , if I go between the orange and red wire I find voltage but not when going between the grey and red wires for the left coil. I do get voltage on all four wires going too the frame for ground. I also verified voltage at the 4 pin connector at the red/white wire, I even cranked the bike over with the stand up and the clutch pressed. Still no spark. I then conducted a continuity test on the wiring going from the tci too the coils. All was well there. I'm pretty sure it's my tci because that's all that's left that I know of. The voltage thing at the ign coil feeds has me curious though.

 

you read voltage to coils from battery ground not the orange and gray wires. orange and gray wires are what the tci controls to fire coils , opens and closes the circuit to cause the coils to do there firing. hysteresis

there should be a black/white on tour tci with a covered connector about 4" away from tci unplug it .

 

If you need a pic, let me know exactly what pic you need, and I'll see what I can do. If I can't get the pic, I can try to take one on one of my bikes.......

 

Hopefully that works and the TCI comes back to life. The B/W wire disables the TCI when ground is applied, so disconnecting it will eliminate the possibility that the TCI is disabled because of a failing safety circuit. You can also temporarily remove the side stand relay to defeat the ignition cutoff safety circuit.

Did you replace the broken diode yet? I just looked in Len's catalog and he carries it - info@xj4ever.com to order.

HCP435 OEM main harness wiring SINGLE DIODE, with harness lead and connector, located under the fuel tank within the main harness. Fits all 1982 XJ750 Maxim and XJ1100 models.

Also wondering about the special testing that you mentioned in the first post. Did you ever apply 12v directly to the ignition coil Orange or Grey wire? If so, the output transistors on the TCI could be damaged. You could ohm those corresponding terminals on the TCI to the corresponding black wire terminal on the TCI. They should check open or very high with a good TCI.