Hey ccharr. This truck came from your neck of the woods. I have to admit it is fun to drive just need to get on this electrical and like they say enjoy the ride
Welcome scot ! Don't be in any hurry to change that GMC driveline ! . You'll find once tuned the engine has gobs of good , useable power and the Dual range Hydromatic transmission is one of the best automatics ever made ~ it'll easily run you down the road @ 70 + MPH . Tune and service it then drive it and get a feel for why GM makes the MOST POPULAR trucks in America . There's a LOT to proper service and tuning , valve adjust then points , then timing , then open those spark plug gaps up to .035" or more...
I got it running good now. Just need to get all the lights to work so i can get up on the freeway with it. What about just doing the 12 volt conversion?
The 12V conversion is straightforward, and allows you to use readily available and affordable parts (lights, alternator, etc.). Stoveboltengineco makes a mini-HEI, or you can step down the voltage to your coil so you don't burn your points up. 6V starter will be fine on 12V (spins over nice and fast!).
Thanks i think instead of tracing all the wiring ill start the 12 v this w/e. This was a barn find has been hidden away for over 30 years i know i do have a couple of leaks have to really clean it up and see where there coming from
As you are going through the conversion, Check all grounds and connections to the lights. Check the wiring at the junction blocks on the inner fenders. As for the coil...an IC64 coil from NAPA is 12v with internal resistor to eliminate the ceramic resistor block. Do the Flamethrower points eliminator also. Put a Runtz resistor on the gas guage. Replace all bulbs. I really like the Sylvania Silver Star headlights. Install an alternator, a one wire is easiest.
Electrickery Fun ! Be aware that converting it to 12 volts means you'll still have non working lights etc. You only need the $99 stock harness too ~ 12 volts works fine & dandy , wires don't care . How much crap will you be adding ? radio & CD Player ? no fancy harness necessary , most folks wa$te $ better spent elsewhere like on new tires , upholstery and so on and don't need the complicated " painless " modern harnesses . Think before you act , it will improve the fun you'll have driving it .
Thing is i already have the harness was going to use on the bucket i got rid of i also have a brand new alternator so i really just need the bulbs and battery heck i even have 2 s10 rearends a 350 motor and a new turbo 400 but i think i only want to do the 12 volt for now
If the insulation is in good shape, the factory wires are more than adequate, but all of them I have seen are cracked and peeling. The harness is not hard to install, just take your time and plan it out. Make shure all grounds are good and feel free to add more, especially engine to frame, engine to body, multiple body grounds, etc. Clean all rust and paint from the metal where you ground any wire. I also like star washers under grounds.
Good idea on the star washers never thought of that ill see if i do a quick trace and can get it quick without the harness if not ill start installing the harness
Get out your multimeter and check for 12v at the terminal ends of the lights. If you have 12v, look at the grounds. If you don't have 12v, start tracing the wires back to the switch to see where you loose voltage, probably a disconnected junction or a broken wire. Make shure the wires are still attatched to the headlight switch.
Well got the headlights to work and the dimmer switch. Found that the tail lights are not hooked up and missing the inner parts so ill work on that next
Awesome! and yes another GMC! Trust me you want to get it on the road and drive it! You will love that long GMC motor. I love my 228. I have used mine to haul and haul and haul and it works just fine. Pulls no problem. I remember some of converting mine over to 12V neg ground. Take your time no big deal. I remember having my headlight switch hard to pull. I used some WD 40 and then some contact cleaner. Now it works as it should. Also I remember after fixing my gauges that there were 3 wires on the amp meter. I had to have those on the right posts for everything to work. I went through all the possible combinations. Tail lights are fun. I got them from our host here. The toughest part for me was to get the wiring correct into and around the turn signals. My truck didn't have it. I got that relay for it from our host as well. Now post up a pic of that engine bay and interior. The engine bay may cause some extreme jealousy from tour Chevy brothers...
I just got done ordering some parts from the host. Real good prices Im going to see if the tail lights will work with 6 volt if so ill gather the rest of the parts i need for the 12 v conversion
If it already has a 12v battery and is negative ground, someone has already done that conversion for you.
Wiring 6 or 12 volts , the job makes no difference ~ In fact , you can use the original 6 volt harness in 12 volt conversions , just change the bulbs , relays and so on .
