i have seen that some aftermarket lights require a relay to carry the bigger load that they use. i did not think it applied to Halogen but not sure. i could test it to see what the amp draw is but wondering if anyone know off the top of there head so i don't have to test it. of course i should test it myself but just lazy.

 

I have used Halogen bulbs in the high beam position for many years with no problem. I kept the originals in low beam since they are used in town, in traffic, etc and did not require the extra visibility. The Halogens give that extra long range visibility for the open road.

There is a difference, though, which I found out with a '66 Mustang I had that had a weak circuit breaker. On I-64 near Williamsburg, the lights suddenly went out at 65mph and it was pitch dark out there. Sudden panic is not the word for it. I got stopped OK and after a few minutes, the breaker closed in again and I was able to keep going as long as I just used low beam.

 

My daughter uses sealed beam halogens and does not require a relay on her '68 Cutlass, but I have H4 and H1 bulbs in my wifes car ('68 442) and use a power relay for the high beams cuz when the four lights are on it will trip the breaker, so depending on the wattage of the bulbs you are using will determine the need of a relay...I have H4 bulbs in my '57 and have not needed a relay but I have not had the high beams on for long periods of time...

 

If you are using std off-the-shelf halogens, you should be fine by simply replacing them. I replaced my old T3s with std Wagner halogens from the local parts store and they are GREAT! It is nice to be able to see well in the dark... The bugs like them, too.

If you are using some special hi-wattage bulbs (over 65W each), then a relay will be needed, and possibly an alt upgrade, depending on what you have in the car. However, I do not see the need for them in regular driving.

My old Ford developed the "flashing headlight" syndrome last year. The breaker in the light switch was getting weak after 151K miles and was replaced. Some of the darn light bulbs outlived the switch itself!