Old car and state of the art headlights

I’ve been restoring my Dad’s 87 Toyota Corolla FX-16 Hatchback and I’ve hit a snag.

The problem is the headlights. I noticed the car had weak hadlights, even on high-beam setting, and so I went ahead and replaced the bulb with Sylvania Silverlight bulbs.

The bulbs work great on low setting. I czn see the road in a clear and penetrating light I have never experienced before.

But when I try the high-beams, the light actually dims, and to sub-standard levels. I can’t see twenty feet ahead.

Any ideas what is going on? thanks gg

I suspect the original problem (weak headlights), and your current problem are one in the same. I suspect there is a high resistance connection somewhere. That could be anywhere from the battery to the lights and it includes both the positive and negative wires, any relays and switches etc.

Thanks, I thought it might be electrical too, but didn’t think to look for resistance. I even have the meter.