Does onyone know if there is a quick way to test an H4 headlight. I have power at the headlight plug but the light does not work. The bulb does not look like it is burnt out.

 

Try and start with 2a alligator clips. Put the ground to the ground prong then the other wire to another prong. Try and flick the the lo/hi beam switch to see if either lights up. Then try the other nonground prong- post your results.
Somebody smarter will tell you to just try a multimeter set on dc and look for 12the volts dc at the hi and low prongs when switched accordingly

 

Connect the bulb across a battery to see if that works ok and if all good then you dotta look at the terminals in that connector block because often the grouind terminal get s hot and then gets all baggy and won't make a connection to the bulb.

Clean the connections and squeeze them with pliers to see if you get a light.

 

Quick? Try another bulb! Easy. With care you can test it across the battery as Spanners suggests. Just keep your fingers away from the glass!

 

I used to own an old Ducati 450 one lunger that would shake the filaments loose at the base of the bulb. A new bulb wouldn't last 4 months.

I would resolder the connections at the base of the bulb.
Then I would drill a hole in the side of the base and fill it with silicone.
They lasted a lot longer after that.

YMMV