Hi, 97 blazer 4wd, 4.3 l .i have tried the forums but cannot seem to find a similar issue. A few weeks ago my low beam headlights stopped working, now they are flickering on and off When this happens orher lights flicker as well.

Today I pulled the switch to test , and noticed it gets extremely hot when lights are on. The switch also seems to click as the lights flicker.

Checked relays, and swapped the 2 that are the same, no change.

Light switch seemed to have a low resistance measure, both parking lights and headlights.
Also noticed when i turn lights on there’s a large voltage drop on the dashboard gauge about 13 to 9 volts.
Havent checked grounds yet as i can’t seem to find them.

DRL work as do high beams. All other lights work.

is the switch defective? Any other ideas?

Any help would be appreciated.

 

Seems like there is a charging issue possibly, have your alt checked and battery, if those are good check your grounds.

 

I'm a professional electronics tech, so I'll operate from general principles. Heat is produced by current through a resistance. It's actually the square of the current times the resistance, so even a small resistance between two contacts can cause problems if there's enough current. It can be hard to measure contact resistance. Many DMMs aren't that accurate at very low readings. (I have a special low-Ohms meter for this.) The heat then degrades the contacts, making the problem worse until they burn out.

But your situation sounds to me like you may have an intermittent wiring short somewhere that is pulling more current through your headlight switch than it is designed for. That would explain everything you're observing: the low voltage readings, the hot switch, and the flickering lights.