red plug/black cap (diodes)

[bikerdave]

Hello all , can somebody tell me what the diodes do Thanks

[eaglerider]

Cannot exactly tell u, but the bike will not run, or (I think) start, if it is missing or bad.

[mradam]

which ones...i have not dug into the electrical on this bike yet, but if you pointed them out to me i might be able to give you an idea.

[eaglerider]

The diode is plugged into the wireing harness in the back part, under the seat, on the rear fender.

[zekkfett]

A diode blocks current from flowing back down a wire. It only allows current to flow ONE way. Most likely, it is for the turn signals or brake light; so that when you turn on a turn signal or brake, the rest of the lights, or the brake light will not flash.

I'm going to do a LED conversion to all my lights, and there has to be a diode in the lights to control just that. As everyone knows, the brake light has 3 wires; brake, run and ground. You put a diode on the brake wire, so that the run wire does not have current running backwards, possibly ruining the electronics, since both wires run to the same output. And also so the run wire does not have double the current.

The diode needs to be in there. If you get flashing brake lights, (and I don't mean a subtle dimming) or any other lights, when your signals are on, or your turn signals both come on with the brake applied, then the diode needs replaced, but it needs to in there. There might even be more than one.

I have an electronics background, and most diodes are pretty tough, and built into the wiring of just about every bike, whether you know they are in there or not. Diodes are polarity specific; they are like fuel filters, one way flow only. If you have to replace, be aware of that.

[Rob]

This one is tied into the main ignition wiring to protect something in the ignition circuitry.

and she no run if you blow them (mulitiple diodes inside the red chummy)!

Its all part of your pick up coil and igniter testing in chapter 15.

And as for light wiring they are required when trying to make an after market 2 wire LED module work like a 3 wire for the front signal/running lights to work to DOT specs. (or they will only be marker lights)

and sometimes you have to swap out the flasher unit to a variable load model so the LED's dont flash to fast.

If your just changing the bulbs out to LED bulbs, they are built into the 1157 bulb light base for the brake/tail light.

No modifications needed

[zekkfett]

That particular diode is to protect both coils from firing at the same time, and to stop current from going to the opposite coil, given they both have the same trigger. When a diode goes bad, no flow goes through it.

Rob, I've got all the plans for the lights, making them myself. Replacement LED bulbs are NOWHERE near bright enough to make any kind of useful lights.

[bikerdave]

Thank you guys I will be sharing pics of the little hotrod soon

[reddirtranger]

I picked up an 85ltd model for pretty cheap recently. Its in good shape really, and i believe my problem is a simple one.
it was missing the reg/rectifier and not getting spark so heres what i know.
It now has a reg/rectifier
Its got a fresh battery and fuses.
the coils test fine as far as i can tell
(my meter is an electricians auto meter so i cant set it to 10k).
I know my key needs to be jiggled a little to get the starter swith to engage but it does.
I have connected the kick stand switch wires togeather(have not yet bypassed them as mentioned above).
the bike is in neutral and n.light is on.
New spark plugs.

I am missing the red diode under the seat. It should be in the mail today.

When i probe the pos/neg terminals on the ignition coils i get a pos reading just having the key on and no started button pressed.

My concern is frying a red diode, so is the dual signal something i should be concerned about before i plug it in?
i have not tested the pick uo coil