Motorcycle turn signals

I am looking for something like a pulse on, pulse off timer relay of about 20 to 30

amps. The pulse would be of the same polarity. It would be to power 

turn signals on a trike. I am using HD handlebar controls which have a

momentary or hold for on switch. On the factory bike they are swicthed on by a

pulse and switched off the same way. Or if you start moving the speedo pulses

them off.

 

Maybe look into the Versitimer 3 from Peripheral Electonics. The VT3 converts a pulsed input to an adjustable (1 to 60 second ) output. Input may be positive or negative. Negative output with LED to indicate timing cycle in progress. The VT2 also features a brake lead to cancel timing cycle. Features Leading and Trailing edge input triggers. It cannot handle the 20-30 Amps you need but the signal out of it could be wired to a relay.

Jim