I have a 96 blazer LS. the headlights appear to be dim. Could this be a grounding issue?

 

Well, depends, do they just stay dim?
or do they fluctuate, get brighter and then dim.
If they just stay dim, your bulbs could just be getting old, Halogens as they get older, they start to dim down, your lenses could also be oxidized

If they fluctuate noticeably, It could be a few things, could be a ground (easiest thing to check) or it could be your alt going bad

 

Search for; Big 3 mod; Alternator PWM mod; & Headlight Relay mod; All needed 'resifications' for these trucks

 

seem to just stay dim. will change the bulbs. thanks for your help!

 

will check it out. Thanks for your help!

 

Umm. You have this mixed up, The big 3 is the charging wires, the ground from the alt to the frame, power from the alt to the battery, and the battery ground to the chassis/frame

I would try a new set of bulbs first, Check out silvania silverstars or Philips XP's, I have philips xp's and they are unbelievably bright

 

I am not getting voltage drops, so I will do a little resto to the loghts themselves. Thanks for your help.

 

Yup Rich. The Alt PWM mod references the alt to B+ of the bat not the PCM. The headlight relay mod sources headlight current from the bat, not the dash switches. The big3 lowers impedance for all electrical loads. I will also look into Philips XPs Are they a better value than Silverstars?

 

I have tried both, even side by side, and Philips XP's are brighter, and produce a more white light than silverstars. I have not done the test on a car without a harness though, But I would imagine the same outcome.