I have a Sylvania Hi/Lo beam Headlamp assembly, i wanna just wire it in for fun. I am thinking of running a power from the battery and then to the light with a switch in between.

If i just run the power and ground it....will i blow it up instantly? What size fuse will i need to run to avoid blowing it instantly?

Also there are 3 pins on the back, any idea how to find the LOW, HIGH, and GROUND pins?

Thanks

 

Why are we doing this for fun?
Do you have an application need?
To find out the terminals, get the proper plug and test the combinations.
Black should be neg common.
If you really want to install for application, plan on using an inline fuse at the battery, use at least #12 wire and place two relays.
Power the relay windings with the same 12 volt supply as the lamp feed and run two single leads into the cab and switch them to ground for hi/ lo.
Feed the power to the lamp hi and low thru each relay tranfer contacts.
Use a center off switch type.
Switching direct power in and out of the cab isn't cool these days. To much chance of fire beside voltage drop.
Good luck.