Alternating flashing lights?

Im not even 100% certain this setup will work... but as for pulse length's... it all depends. If it was me, i would make the ground pulse longer than the 2nd, and the 2nd bulb blink faster.... been a long ass time since i have worked with capacitors.. but i would guesstimate and say.... Ground= 2k and 2nd bulb 1k? this would give you probably a 1sec flash off of the 1st bulb and a faster flash off of the 2nd bulb. That is... if my diagram is functional and working... as for them alternating back and forth... on a timed circut.. i have been playing around with this in my head for hours and im not certain it would work at all either... will let you know if i come up with anything...

In fear of posting another picture all messed up, i'll leave a link. http://members.toast.net/mikeshonda750/image2.jpg

Pretty much.. the relay on the left sends a positive pulse to relay #2 via a capacitor of your choosing. Each light is tied to terminal 87 and 87a... so as the pulse is sent.. relay #2 opens and closes.... sending juice back and forth between the 2 bulbs.

I wouldnt even begin to advise you on what size capacitor to use on relay #1 to ground. I would simply take a few bucks... head to radio shack... buy a few 12v bulbs.. relays... wiring.. a toggle switch and various sizes of capacitors(they should be fairly cheap) and wire up a demo type thing so you can make sure you get them flashing fast enough and dont burn up relays and such..... again.. this is just an idea i have been playing with in my head since i 1st read this post.... might work... might not... hoping others could go through my crude diagram and visually tell us (you) if it would function properly and not be too stressful on the relays and such.... dunno

Good Luck!

this worked for me...

Headlight Flasher

This circuit was requested from an email. It will allow your car headlights to flash on and off at the same time or it will cause them to flash alternately. The circuit is based on the 555 timers. It is used in the astable mode. The 555-timer output will go high for an adjustable period of time and then turn off. It will then repeat the procedure. The time is adjusted by R1. To hook up the circuit to your car you must locate the positive wire from the fuse box to the headlights. Cut the wire and insert the relay contact and bypass switch. The bypass switch will allow you to bypass the relay contact for normal headlight operation. In the alternating headlight configuration you must cut the positive wire to each headlight and wire in the relay contact.

Where or what does the red wire off the top of the first relay connect to?

and is the 12v wire on the bottom from a switch or constant?