How to test these Diodes?

[Seirra117th]

Ninja 250r 2008

thanks again everyone for checkin out my post.
any help qould be greatly appreciated.

so i was trying to test these......








Q1 does the black cap come off to reveal the diode?
Q2 or is it 2 of the terminals im testing
Q3 are all 3 diodes rated the same



thanks again for any responses

[Seirra117th]

ahahahaha ill answer this one myself.

READ THE INSTRUCTIONS CAREFULLY

[Seirra117th]

i had just read somewhere that someone replaced the dioide itselfnot the assembly, hence why i posted ��

[DannoXYZ]

Originally Posted by Seirra117th

so i was trying to test these......



Q1 does the black cap come off to reveal the diode?
Q2 or is it 2 of the terminals im testing
Q3 are all 3 diodes rated the same

All YES. Easiest to test by connecting probes to terminals. Using some test leads with alligator clips makes it easier. Let’s use the 2-terminal single-diode as example:

Test#1 - connect red probe to terminal-1, black probe to terminal-2
Test#2 - connect black probe to terminal-1, red probe to terminal-2

Repeat for terminal-3 & 4 and 5 & 6 of triple diode assembly. One reading should be close to 0 and other way significantly higher.

I’ve never heard of one failing in my 40-yrs of riding. Not on bikes, not on autos. Previous person most likely did not test properly or had an interlock switch in wrong position and bike wouldn’t start. So they blamed diode and replaced it. In event you do find an improperly replaced diode and it has failed, replacements are easy to obtain: https://www.newark.com/nte-electroni...-41/dp/10M2938

I’d say that interlock switches are responsible for 99.99999999999% of no-start issues. People just don’t want to test and measure to diagnose and find problem. Problem with that is they waste time and money replacing perfectly working parts with brand-new perfectly-working parts and nothing changes.

[Seirra117th]

ok i thought i was getting mixed up abit.....ill teat all 3 dioides then

the black caps are very hard to get off the conectors �� was worried they would break

ill post results soon
thanks heaps for your help

[Seirra117th]

ok so how do i get the black cap off.......ive tried pullin prying carefully but they allnseem stuck

[DannoXYZ]

No need to remove black cap
Just test the terminals. You should have 6 different readings
Please them here.

[Seirra117th]

ok 1st one
a-b approx 300
c-d approx 300
e-f approx 40
with the probes swapped around i keep getting OL
but the e-f terminal does 40 both ways
im guessing defective

[Seirra117th]

btw i had no sound before testing them......then i have put them back in the opposite sides now i get a buzz from the starter......so i guessin the starter one was defective b4

[Seirra117th]

here are the tests on the two 6 prong connectors

im wondering if ef is the problem.......i could replace the part from kawa for 90 dollers or just the diode for 90 cent

but still cant get that dam cap off 😆

[DannoXYZ]

wow, good job testing!!!

That 3rd one does look defective. Possibly the “repaired” one. OL = Open-loop? Infinite resistance, which is good. Diodes are supposed to conduct one way only.

To remove cap, clamp plastic body in vice. Try prying tab on plastic cap outwards, i see one on right side of your photo. If that doesn’t work, position so bottom edge of black cap is level with top of vice jaws. The insert large flat screwdriver and pry down against vice to force cap upwards. Might break off a tab or two, no big deal. Use silicone to re-attach.

Buzzing sounds like not enough juice from battery though. Make sure battery and jumper pack are both fully charge. Or use an auto-battery to jump from (auto engine off).

[Seirra117th]

mate thats awsome thank you heaps for your help

my local elec store only has 4004 1A 400V Diode would the jigher rated diode still be ok?

[Seirra117th]

and thanks heaps for the positive feedback

really encouraging ��

[DannoXYZ]

You're most welcome. Making great progress!

Originally Posted by Seirra117th

mate thats awsome thank you heaps for your help

my local elec store only has 4004 1A 400V Diode would the jigher rated diode still be ok?

Yup , should be same item I linked to from Newark. 1N4004 has sliding rating depending upon voltage. So 1a@400v = 30a@1.1v . This is used in very basic boolean-logic driving starter-relay, not much power at all.

Once you get black cap off, take close-up photo of diodes. Might be able to identify original one, and failed one.

[Seirra117th]

totally love all the help hey

off to elec store now ������

[Seirra117th]

has someone glued these or metal clips?

[Ralgha]

Third diode is definitely bad. I'm guessing that when it was "repaired", they shorted it somehow and blew it out with too much current. Whatever the cause, it's definitely toast.

[DannoXYZ]

Originally Posted by Seirra117th

has someone glued these or metal clips?

Looks like it may have been glued back in?
Hold it in vice by sides of white connector so you don’t damage locking clip.
With black cap up.
Then maybe make 3mm cuts with thin cut-off wheel to remove cap in section

[Triple Jim]

Originally Posted by DannoXYZ

1N4004 has sliding rating depending upon voltage. So 1a@400v = 30a@1.1v .

You're misinterpreting the datasheet. The 30 amp rating is for one half of a sine wave, non-recurring, which is 8.3 milliseconds in duration. The maximum average forward current rating is 1 amp, regardless of voltage.

Of course any of the 1N400X series is fine for this application.

[Seirra117th]

and were still going.......gonna just cut the black cap off all together......i can get a replacement but lets try and fix this one

[Seirra117th]

hmmmm diodes enclosed in plastic?



so do we make our own diode assembly?

[Seirra117th]

gonna keep cutting and probably make a new diode assembly

has anyone disassembled one of these before?

thanks again for everyone's help

[Seirra117th]

dont think im gonna get too the diodes.......

[Seirra117th]

inside the black cap

[DannoXYZ]

Hmm, looks all potted or epoxied together. You can try repairing yourself by reusing terminals. I may have spares somewhere. Will be back from vacation in couple days and can check my spares box. PM me your address.

[Seirra117th]

i was thinking of building the top half and reuse the terminals .
atleast ill be able to replace any if a curcuits made it blow.

The bike came with not much info but has led blinkers thay all come on at once.....so gotta read the fix for that sometime, wasnt sure it that could cause a problem with the diode.........or idk what causes them to fail.

[Ralgha]

You mean all four signals come on at once, or just both on the left/right come on steady? All four is probably a wiring problem, two on the same side is fixed with either a new flasher relay that is designed to support LEDs, or resistors in parallel with the signals to increase the power draw. The OEM flasher relay requires a minimum amount of power running through it to make it cycle, and LEDs often don't draw enough.

Looks like those diodes are potted in a plastic housing, might be a lot of work to get those terminals out in a usable condition. One option is to jury rig the new diodes just to see if it solves your issue, and if it does to buy a new OEM diode assembly, I think they're about $40. Quite a bit more expensive though.

[Seirra117th]

Originally Posted by Ralgha

You mean all four signals come on at once, or just both on the left/right come on steady? All four is probably a wiring problem, two on the same side is fixed with either a new flasher relay that is designed to support LEDs, or resistors in parallel with the signals to increase the power draw. The OEM flasher relay requires a minimum amount of power running through it to make it cycle, and LEDs often don't draw enough.

Looks like those diodes are potted in a plastic housing, might be a lot of work to get those terminals out in a usable condition. One option is to jury rig the new diodes just to see if it solves your issue, and if it does to buy a new OEM diode assembly, I think they're about $40. Quite a bit more expensive though.

yep when i push left or right indicator all the blinkers come on steady.....front and rear.......prev owner had put led blinkers which i was thinking is the wiring problem......because the meter indicator lights dont come on either?

If you mean jury rig as in just solder in the diodes without the connector........if it blows again EASY CHEAP FIX until the shorts gone then replace with OEM......thats what i was thinkin of doing

[Ralgha]

Originally Posted by Seirra117th

yep when i push left or right indicator all the blinkers come on steady.....front and rear.......prev owner had put led blinkers which i was thinking is the wiring problem......because the meter indicator lights dont come on either?

Actually, it's probably not a wiring problem, it's probably rooted in the LEDs not using enough power. Adding resistors could fix it, alternatively a new flasher relay combined with some modification with diodes at the gauge indicator should fix it.

Originally Posted by Seirra117th

If you mean jury rig as in just solder in the diodes without the connector........if it blows again EASY CHEAP FIX until the shorts gone then replace with OEM......thats what i was thinkin of doing

That's exactly what I mean.

[Seirra117th]

So here are my Diode assembly tester (until OEM ones come)
any concerns please send em





and then some heat shrink





and just gonna tape em up aswell

Diode tested each one and get 0.55v drop (if im reading the test correctly)
and nothing (OL) and the reverse direction

[DannoXYZ]

Those diodes you repaired only deals with starter circuit.

All 4 turn signals flashing is caused by swapping in LED turn signals. To fix, you need to install 2 diodes in-line with turn-signal indicator bulb on dash.