diedo block what dose it do

I have an xj550 and it is done and finshed after 6 months but now i have it done it dose not want to work as i put it all back as i got it out and when i went to start it smoke came from tje head light area so switched it off and opend light then put it back on and it was fron the diedo block can i fully remove it and if so what will not work or where can i get a new one from in the uk.

 

No, you can't just remove it.

It contains diodes that are part of various, different circuits on the bike. Yamaha conveniently located them in the same "block" even though they belong to different circuits.

WHAT circuits they each belong to will vary from model to model; your Euro-spec XJ550 will be different from the 550 Seca sold here as well as different from the 550 Maxim.

You need a circuit diagram specific to your bike to figure out what each of the diodes are for.

 

Can i just buy a new one its a xj550 maxim on a 1982
If so do you or any one know where in the uk i could got one

I have looked on ebay and there is one but it's for usa amd postage is 30 pound

 

you need to find the cause of the failure, putting a new one on a faulty circuit will just result in wanting another new one .
I thought the diode block was under the tank?
circuit diagrams are here
http://xjdiagrams.thundervalleypower.com/
stu

 

I can find lots for yamaha but not for xj550 will they all fit as they all look the same and have the right wires in the same place.

 

The diode block for the xj550 4v8 is also used on the following other Yamaha models:

TDR250 (88-90) , XJ650 4K0 (80-) , XJ900 31A/1FW , XV12/XVZ12 (83-)

Yamaha part number :4L6-81980-M0

I think they are still available new in the UK, but you may be able to pick one up cheap by trawling ebay

Hope that helps

 

The 550 Maxim is a "5K5" and the pn for the diode block is 4U8-81980-M0-00, the same as for the USA-market 550 Seca (4U8.)

Another member and I had compared a 4V8 (Euro-spec 550 "Seca") and a 4U8 (USA-Market 550 Seca) diode block a couple months back and discovered that the number of wires and their placement in the connector were different between the two.

The 4L6 part number is likely not going to interchange. The 550 Maxim should use the same part number as all the USA-market 550s.

 

Sorry, yes, my part number is for the 4v8 only. Mind you, there seem to be more maxims now in the UK than original UK Spec bikes, so you stand a good chance of getting a used one.
They are still available new for about £25 from Yamaha
Linky: http://www.cmsnl.com/products/diode-ass ... u881980m0/

 

This might help. This is a pic that clearly shows the diode block in a USA-market 550R, which is pn 4U8-81980-M0-00. Ignore all the circles and letters, they're from a different article. The diode block is directly below the lower red circle.




If that looks like your diode block, then that's the part number. If not, then we need to have somebody give us a look at a Euro-spec part, the 4L6 part number.

HOWEVER: The diode block itself is not the problem; yes you may have killed it, but it didn't smoke because IT is "bad" something else is wrong.

The diodes in there are part of the sidestand/clutch switch/safety circuit and the headlight relay "latching circuit." You probably have a dead short somewhere; not good since the headlight latching circuit is tied directly into the alternator/regulator circuit.

You need both a wiring diagram and a circuit diagram; PM me with an email address and I can send those to you.

 

I will look round for new / used block and go over the loom once more then if it bose not work i will have to try and make a new loom if it is posable to do so or i am stuck with a bike that dose not work

You can see the loom in mods forum under
My xj550 first build

I have just had the diode block off and taken tape off it and this looks like the short and only part that is f… just look at this what some one has done to it no wonder it dose not work and has smoked once power is on i was looking online and the shape was all wrong now i know why ………

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This could have cost me if i just got on and went for ride i have found one for 27 pounds new

Thank you for your help so far you all rock

 

Just for reference if any of you are looking for a diode for your 550, they are the same as the FJ1100 and early 12's.

http://www.cmsnl.com/yamaha-fj1100n-198 ... u881980m0/

 

Those components could be replaced for 2 or3 dollars

 

Now we can finally see inside of one! Time for someone to do a write-up!

Lol

Dave

 

Yes and if they do i may try and fix it better than the last person did ha ha ha

Ok that note there is no side stand switch on side stand relay they have been looped out could this have shorted the diode block just want to know before i put on the new one