OK, so i went ahead and did the headlight relay mod.
I used 3 relays, so i could have lows on with highs.
Before the mod, i had 12.37 volts to the lows, 12.5 to the highs.
After i had 14.12 to the lows, 13.96 to the highs (but lows were on too).
Definitely brighter.
I ran 10 gauge wire from the alternator to the circuit breakers, and 12 gauge to the relays/lights. I was going to run all 12 gauge, cause thats what side spade terminals i found, but then i found some car stereo power/ground wire kicking around that was 10 gauge, so i used that from teh alternator. I mounted the 2 cb's and 3 relays really close together in the drivers front corner under the hood. This was my first wiring job on the burb, and i wanted to do it all right. All connections were shrink wrapped, even ring/spade terminals were sealed with heat shrink to the wires. Dielectric grease on all connectors. Hid all the wiring i could in stock looms, even managed to hide the 12 gauge wires running from teh drivers side to the passenger side in the wiring loom that runs under the radiator. I impressed myself how anal i was through teh whole project.
I ended up running a ground on each side to the core support dedicated to the lights. When i get time, im going to run new dedicated grounds from frame to body, body to battery, etc. I ended up just using spade connectors to connect to the light bulbs, as i didnt' want to use any of the small factory wiring just to retain the sockets. I couldn't find new sockets. I managed to zip tie everything to the old bulb retaining clip deals, so hopefully they won't come loose. If they do, ill order some new sockets.
Anyways, not really anything new, but wanted to post my pics. I only ran 2 cb's, cause i thought it unnecessary to run a 3rd just to feed the relay that keeps the lows on with the highs. I forget where i tapped this from, but i think i took it off the low beam headlight cb, so if the circuit shorted, the high's would still work as normal.
Went up to the mountains a couple weekends ago with it, and the increased light was awesome! about 1/4 of the time, the high's don't light when i pull the stalk, but i think the relay i used may need to be replaced. They were cheap off-brand ones. If not, i may need a new high/low switch. And my headlight switch is going out, so that may have osmethign to do with it.
Anyways, on to pics!
Before Mod, Lows, compared to 94 Blazer stock lights
Stock highs
Ground Wiring Harness for low/high on one side
Shrink wrap closeup - cause i impressed myself

Bought the heat gun and stuff from HF just for the project
Female spade terminals i used to connect to lights
Ring terminal heat wrap breakdown
Power wire from alternator
Breaker to breaker link for power feed
Passenger side wiring
Spade terminals hooked to bulbs
Relays and stuff - started out neater, but i wanted to keep the mounting location compact
CB's, located down to the right of the relays - sorry about crappy pic
Feed from alternator - will move if the wire loom starts to melt
High beam comparison after mod - no idea where the low beam pic went
Thanks for reading my long post! I know its pretty typical stuff, but i always like seeing what everyone else is doing, so i posted lots of pics. Thanks for everyone's help along the way on this truck!
