Unidentified component in wiring harness

[gleno]

WTFIT:ummm:

I have been rebuilding/repainting my 1988 Canadian import.

While trying to isolate a vboost problem I found this unidentifiable component lashed into the wiring harness.

It connectes to the green wire and the blue/white wire. Both these wires have multiple reconnections to other relays and switches.

Was this a factory lash up Or some mod done by a previous owner?

What is this component anyway?

 

[Rusty McNeil]

Looks like maybe a small diode?
Could be a resistor but that would be super low wattage based on physical size.

Weird...

 

[gleno]

Looks like maybe a small diode?
Could be a resistor but that would be super low wattage based on physical size.

Weird...

Thanks for the feedback rusty:eusa_dance:.

I'm stumped on this one.

Don't know what it is so I can't figure out why it was put there:confused2:

 

[johnpclynch]

It certainly looks like something the PO put in - there's a mismatch between the connectors, only the green wire looks original

Could it be a resistor for a set of LED indicators?
A diode for an aftermarket fuel pump?

What connectors/side of the bike do the wires run to?

 

[RempageR1]

Hi,

Did this Vmax used to have an alarm on it? On one of my previous bikes, there was a diode between the indicators and the fuse box. The reason for it was that if the alarm sounded, it would turn on the indicators. They would then feed the fuse box which would in turn feed all other electronics (except starting the bike off course).

 

[gleno]

It certainly looks like something the PO put in - there's a mismatch between the connectors, only the green wire looks original

Could it be a resistor for a set of LED indicators?
A diode for an aftermarket fuel pump?

What connectors/side of the bike do the wires run to?

AHHHHHHHH.... I knew someone would ask this question..

The green wire runs to common spliced junctions with....

Relay unit
Sidestand relay
V-boost valve control unit
Fuel pump relay

as does the blue/white wire because it is connected to the green common junctionn via this weird part.

Diodes are a one way gate to electrical flow and are normally used to stop 'backflow' signals (i.e. suppress electrical noise).

Maybe the part n eeds to be removed?

**** info from the wiring diagrams SO I've hand balled this to the forum.

The big question is WHY are the blue/white wire and the green wires connected with this component?

 

[gleno]

Hi,

Did this Vmax used to have an alarm on it? On one of my previous bikes, there was a diode between the indicators and the fuse box. The reason for it was that if the alarm sounded, it would turn on the indicators. They would then feed the fuse box which would in turn feed all other electronics (except starting the bike off course).

Don't know previous history.

 

[gleno]

Question for Sean Morley.

What is this part?
Why is it there?

If I cut it out what doi I connect the GREEN and BLUE/White wires to?

 

[wildweasel_pt]

remove the insulation and try to see any reference number? If it works like its supposed to why not just leave it there?

 

[satariel666]

This is a diode and it exist on the electrical diagram. Dont have the OEM manual on hand right
now but it has a certain function. Dont remove it. Will give you more detail evening.

 

[Miles Long]

On the wiring diagram I'm using ( Clymer, '85-'92 models), there is no direct connection shown between the blue-white and solid green wires.
Which "leg" of the b-w wire is connected to the green?
-starter switch to relay **
-relay out to starter relay
-starter switch to OEM diode assembly, via tap on **
Cheers!
also, the green wire routing does not match what you have described.

 

[naughtyG]

This diode is defo part of the OEM wiring - it allows current to flow one way but not the other. From memory it has to do with the side stand/clutch/starter button circuitry. Either that, or the fuel light, I just can't remember.

 

[gleno]

This is a diode and it exist on the electrical diagram. Dont have the OEM manual on hand right
now but it has a certain function. Dont remove it. Will give you more detail evening.

Thanks man.
So I'm looking at a vintage diode.
How do I determine if its still working :ummm:
What do you suppose it's test value is :ummm:

 

[Miles Long]

This diode is defo part of the OEM wiring - it allows current to flow one way but not the other. From memory it has to do with the side stand/clutch/starter button circuitry. Either that, or the fuel light, I just can't remember.

I can't imagine Yamaha using an individual in-line diode, just seems too Mickey-Mouse to me.
All the model year diagrams I have show a ganged diode assembly, located near the steering neck.
Yup, one circuit of this ganged unit is tied into the Starter switch assembly, and is part of the oil light-fuel light test system. Maybe this part of the gang failed, so an individual one was spliced in?
But like has already been suggested - leave as is, if everything works, great.
If not, then start troubleshooting.
Good luck!unk:

 

[johnpclynch]

The Sidestand/Clutch & Neutral switch diodes are all sealed in the flat diode pack but the Oil Level diode may be seperate in the older wiring looms

One of my diagrams shows a Blue/White wire coming from the Start switch going to both the Starter Relay and a diode which changes to a Green wire which leads to both the Oil Level sensor and a resistor on the Green/Red (or is it Black/Red) wire that powers the Oil warning light

therefore - it's stock and required to light the oil warning light when you press the start button

 

[Rusty McNeil]

To test properly you need a meter with diode test function.

Ohm meter will not usually do it.

 

[one2dmax]

It is for sure an OEM part and I've seen it a few times before. Not sure what specifically was different in the bikes to require using that.

 

[Miles Long]

I can't imagine Yamaha using an individual in-line diode, just seems too Mickey-Mouse to me.
All the model year diagrams I have show a ganged diode assembly, located near the steering neck.
Yup, one circuit of this ganged unit is tied into the Starter switch assembly, and is part of the oil light-fuel light test system. Maybe this part of the gang failed, so an individual one was spliced in?
But like has already been suggested - leave as is, if everything works, great.
If not, then start troubleshooting.

My apologies to Mickey and his gang. I was dead wrong.:bang head: I just looked at the diagrams on Morley's website, and there are many in line diodes shown.
I shall have my wife lash me, as punishment.
So don't touch anything. Just hook everything up, hope for the best! Not the first time I've encountered errors in the Clymer manual.

 

[satariel666]

Thanks man.
So I'm looking at a vintage diode.
How do I determine if its still working :ummm:
What do you suppose it's test value is :ummm:

It looks like schootky diode. Voltage drop on normal diode should be around
0,5-0,6V and on schootky around 0.2-0.25V. And this is what diode test in normal multimeter will show - typicaly in mV so 600 for normal and 250 for schootky.

One of my diagrams shows a Blue/White wire coming from the Start switch going to both the Starter Relay and a diode which changes to a Green wire which leads to both the Oil Level sensor and a resistor on the Green/Red (or is it Black/Red) wire that powers the Oil warning light

therefore - it's stock and required to light the oil warning light when you press the start button

Damn you, you stole my solid explanation :rofl_200:
Gleo, hers your explenation from Mr Lynch.

To test properly you need a meter with diode test function.

Ohm meter will not usually do it.

It will show something but nothing relevant.

 

[Rusty McNeil]

As in all things electrical, I wouldn't screw around with removing it unless you understand exactly what it does, why it is there, and exactly what the expected result is if it is removed.