Diode specs anyone!?

[naughtyG]

OK sorry for the double post but I'm desperate here..

I found this in my harness:

I do believe that it is actually a diode - it was plugged in between a blue/white (L/W) and a green (G) wire, in a clear sleeve just under the TCI unit.

The only L/W wires I can find in the wiring diagram lead to a diode (used for the oil level light circuit) but it doesn't have a green wire on the other end.. (it's B/R, which is Black/Red)

My question is, what kind of diode is this? What do I buy to replace it? I got a 50V 1A and a 50V 2A diodes, will either work?

Does anyone know? :ummm::ummm:

 

[maleko89]

Do you not have a diode block near your ignitor? All the diodes should be there. It looks like someone spliced one together. Yes, that is for the oil unit. The Clymer shows it in between blue/white and green. I am not sure to the spec. You may need to order a new diode block.

 

[naughtyG]

Do you not have a diode block near your ignitor? All the diodes should be there. It looks like someone spliced one together. Yes, that is for the oil unit. The Clymer shows it in between blue/white and green. I am not sure to the spec. You may need to order a new diode block.

Yes I do have a diodes block - that's separate and fine as far as I can tell. I actually didn't look if there were L/W and G wires going to that one..

This one here is separate. I do think it was factory-fitted though, because it used the proper factory crimp-on round connectors I've never been able to find anywhere else.

 

[one2dmax]

I have installed diode resistors when we use LED signals to prevent feedback. What year bike? the 86? Looks like a factory type crimp on the ends (not necessarily yamaha).

Sean

 

[naughtyG]

Yes it is the '86. The only LEDs on this bike are an add-on stop lights that's simply piggy-backed on the existing tail light wiring.

I just remembered that I have a whole spare harness from my spare bike - need to go to Tampa to get it but at least I'll be able to check if it has the same thing in it or not.

It does look factory, doesn't it? And looking at the diagram, it kinda makes sense..

 

[maleko89]

Naughty, talked to Tyler P. and he said to try 1N5404 for a diode.

 

[satariel666]

Naughty, talked to Tyler P. and he said to try 1N5404 for a diode.

Its typical 1000V 3A diode so many can be used like:

1N5402, 1N5401, 1N5403, 1N5404, 1N5405, 1N5406, 1N5407, MR501, MR502, MR504, MR506, MR508, MR510

 

[naughtyG]

Ok so I went to my spare bike's harness and found the exact same component in the same transparent sleep attached to the harness in the same place, so it's definitely a factory mod.
I also worked out that this diode is in the fuel warning light circuitry, and is actually missing from the wiring diagram, so Yamaha must have realized too late they needed it and added it to the harness as an afterthought.

Having replaced it, I rewrapped my harness and put everything back together, and all seemed fine. Rode the bike for 20mns, no problem. Rode it again for 10-15mns, still all good. Then I rode it for maybe 40mns, in traffic getting hot a number of times, and when I stopped....

....mmmmmBOLLOX!!!!! Christine is alive again..:bang head::damn angry::bang head::damn angry::bang head::ummm::damn angry::bang head::confused2::ummm::damn angry::bang head::confused2::bang head::damn angry::confused2::damn angry::bang head::ummm:

So now I know it happens when the bike gets hot (kinda knew that already - it happened the first time after sitting in very heavy traffic in Daytona).

I've noticed that switching the ignition off actually kills the tail light and the fan - nothing else.

And I'm back to pulling the fuses.. WTF is going on!? I had about 70% of the harness unwrapped - all the way from the fuse box to the steering bearings and could not see/find anything wrong, other than that broken diode.

Any further ideas much much appreciated, I'm thinking I might just add a switch in the main fuse cable :damn angry:

 

[satariel666]

According to electrical diagram your problem may be related only with:
-ignition switch
-starting circut cut off relay
-starter switch
-oil level warning light
-our happy diode
-also rectifier/regulator


If you will not find the gremlin in those then i have no f... idea where else to look :ummm:

 

[Buster Hymen]

Ok so I went to my spare bike's harness and found the exact same component in the same transparent sleep attached to the harness in the same place, so it's definitely a factory mod.
I also worked out that this diode is in the fuel warning light circuitry, and is actually missing from the wiring diagram, so Yamaha must have realized too late they needed it and added it to the harness as an afterthought.

Having replaced it, I rewrapped my harness and put everything back together, and all seemed fine. Rode the bike for 20mns, no problem. Rode it again for 10-15mns, still all good. Then I rode it for maybe 40mns, in traffic getting hot a number of times, and when I stopped....

....mmmmmBOLLOX!!!!! Christine is alive again..:bang head::damn angry::bang head::damn angry::bang head::ummm::damn angry::bang head::confused2::ummm::damn angry::bang head::confused2::bang head::damn angry::confused2::damn angry::bang head::ummm:

So now I know it happens when the bike gets hot (kinda knew that already - it happened the first time after sitting in very heavy traffic in Daytona).

I've noticed that switching the ignition off actually kills the tail light and the fan - nothing else.

And I'm back to pulling the fuses.. WTF is going on!? I had about 70% of the harness unwrapped - all the way from the fuse box to the steering bearings and could not see/find anything wrong, other than that broken diode.

Any further ideas much much appreciated, I'm thinking I might just add a switch in the main fuse cable :damn angry:

I've come in late on this thread. Can someone post a complete schematic of the start circuit?

 

[naughtyG]

I've come in late on this thread. Can someone post a complete schematic of the start circuit?

There you go Gary..

 

[naughtyG]

According to electrical diagram your problem may be related only with:
-ignition switch

NO problem here - checked and rechecked works as expected

-starting circuit cut off relay

How do I check it? If the bike's in gear it will not start (unless the clutch is pulled). If the side stand is down it will stall as soon as it's put in gear. All as expected, right?

-starter switch

Bike starts normally, that should mean it's ok, right?

-oil level warning light

Oil light comes on under hard acceleration (normal) and also while the starter switch is depressed.

-our happy diode

..is for the low fuel light, which comes on when the starter switch is depressed, and also when fuel runs low.

-also rectifier/regulator

OK this is my only 'maybe'. I have noticed that the connector coming from the stator looks less than happy (see picture). Everything works and the system is still charging at 13.54V on high idle though. :confused2: When I disconnect the RR from the stator the bike still starts and works, just does not charge. It still won't go off though.. :ummm::ummm:


If you will not find the gremlin in those then i have no f... idea where else to look :ummm:

At which point I'm just gonna cut the main fuse wire and install a switch inline... It's driving me CRAZY!

 

[one2dmax]

Sounds to me like a key switch problem since that's the trigger for the whole mess to supply power to the CDI box. Without that power it should not run (unless it's dieseling which I don't even think is possible on these bikes without melting the engine down).

Got another customer that is having the opposite problem. Ran fine, shut it off and now no spark.

I am going to start another thread in my section on a loan/testing service. Feel free to swing over there and see what I am going to offer.

Sean

 

[naughtyG]

Yes the key switch is the obvious call, but I can assure you it's fine - I've tested and re-tested it.
Also I can see 12V on the brown wire of the ignition switch connector on the harness side with the ignition switch disconnected and removed from the bike..

Definitely a gremlin in the harness - I've disconnected just about everything from it and it was still there, then while I was unwrapping it went away, on re-wrap and re-install everything was fine, and it took a longer ride in traffic for 'Christine' to wake up.

Now hot or cold she won't switch off anymore, so I've temporarily wired a switch in the main fuse circuit and attached it to the fuse box under the faux-tank.

I have the harness from my spare bike (also an '86) so I think it's gonna be transplant time..

 

[tugla]

electrical gremlins suck, good luck buddy, dont forget to scrub up, dont want to infect your bike during operation hahaha

just for fun, try putting the ignition switch from your parts bike.... if your going into it that far worth a shot, maybe when it gets warm it fails

 

[one2dmax]

Sounds like you are back feeding power all the time now from a fused wire somewhere that the harness melted together.

Sean

 

[naughtyG]

Sounds like you are back feeding power all the time now from a fused wire somewhere that the harness melted together.

Sean

Yes that's exactly what I'm thinking. Tomorrow I will have a go at the harness transplant - hopefully the one from my spares bike is intact!

If anyone is interested in a 'Christine'-possessed harness for Halloween I'll let you have it cheap!

Spooooooookeeey :biglaugh:

 

[Buster Hymen]

Yes that's exactly what I'm thinking. Tomorrow I will have a go at the harness transplant - hopefully the one from my spares bike is intact!

If anyone is interested in a 'Christine'-possessed harness for Halloween I'll let you have it cheap!

Spooooooookeeey :biglaugh:

We'll be waiting for your documented write up ( with pics) of changing out the harness! :biglaugh: I hope this cures the problem as I know how frustrating mystery electrical problems can be.