Electrical question - headlight relay needed?

[RICK LAKE]

strictlypersonal Mr. Wizard I agree with the switch is designed for a 20 amp feed. The question is when the system is first turned on, what is the amp ratings for that .2 sec? Years ago I used to run alot of aftermarket accessories, Fog lights, electric fuel pumps, big amps, and compressors. About every year 1 or 2 of the switches would go bad. I would pull them apart and find that their internals where melted and the contacts cooked. Every since that time and adding electric fuel pumps, aux cooling fans, accusump oil tank for preoiling to my cobra they all have relays of either 20-30a or 30-40a ratings. It's the spike of turning on the power and not the steady load of the curcuit running. The relay contacts are twice the size of a toggle switch and can hand the loads alot easier. New cars now have 20-40 relays built internally into the fuse blocks just for this issue. Will your system work without a relay, YES. Mine has the same switches in it from 96 without any problems. Your wiring harness with good ground contacts and the correct wire sizes will not cause a problem. For another car line I wouldn't say the same without seeing the wire ratings and switches. A relay weight is 5 oz. and 4 or 5 wires needed for the curcuit what's the added harm in adding one? Rick L.