switching from two indicator warning lights to one, do I need a diode?

[Spiff]

I have removed the original instrument cluster with the separate left/right turn signal warning lights and I'm replacing it with a smaller 2.5" speedometer but this uses ONE warning light for BOTH left and right turn signals, how do I solve this predicament?
Because If I connect both left and right wire to the ONE yellow wire thats on my new speedo current will flow to either of the circuits and ALL my indicators will be on simultaneously....
I'm thinking I need to install a diode on both left and right wire so that current can only flow TO the warning light and not back in to the other circuit. Am I right?
How do I figure out what diode I need? There's like a billion different types on ebay f.ex..

I made a little wiring scheme of how I think it needs to be. Old setup on the left, new on the right.

[rustybronco]

I made a little wiring scheme of how I think it needs to be. Old setup on the left, new on the right.

Looks good to me.

[tom203]

Something like this would be fine- find a friend who plays with electronics.. he'll have dozens

http://www.ebay.com/itm/10-Pcs-1N4001-Rectifier-Diode-50V-1A-DO-41-/160762398736?pt=LH_DefaultDomain_0&hash=item256e2f8810

[Spiff]

Thanks for the fast reply!

But maybe I'm overthinking the problem, wouldn't another easier option be to lay up a wire from the Load output of the blinker relay to the warning light?

[rustybronco]

If you wired it up directly off the flasher and dependent on the amount of current flow through the indicator bulb, the indicator would stay lit or flash extremely slow.

What model bike are you talking about?

[Spiff]

If you wired it up directly off the flasher and dependent on the amount of current flow through the indicator bulb, the indicator would stay lit or flash extremely slow.

What model bike are you talking about?

So I was told on another forum, so diodes it is!

It's a 78 750GS