262's 1970 GMC

[ericjon262]

Picked up a 1970 GMC last week, the plan is to restomod it, keep it mostly stock, possibly an updated powerplant, definitely an updated transmission(want overdrive), and a good refresh of the paint. interior will be stock.

[MusicMan70]

Welcome Eric, nice truck! What does the SPID show for color code?

[ericjon262]

Originally Posted by MusicMan70

Welcome Eric, nice truck! What does the SPID show for color code?

Thanks!

I have the dealer tag, but I haven't seen the spid anywhere. where would it be on one of 70 model? glovebox?

[ole dollor]

great looking truck you got there, nice score....i like it

[ericjon262]

Originally Posted by ole dollor

great looking truck you got there, nice score....i like it

Thanks, I think I got a sweet deal, I only paid $2300 for it.

I started working on the tailgate today, I'm going to repaint around where it say's GMC white again, and then paint "GMC" red. I think it should look pretty good. I'll post pictures tomorrow.

[ericjon262]

A little bit of progress





The overspray has been removed. overall right now, it's good from afar, but far from good! I'm not too worried about it though, because I plan to replace the tailgate in the near future before I respray it.

Here's a shot of the SPId sheet. hard to make out, but the color was listed as Dark Gold.

[ericjon262]

it's dirty under there...



what is all of this???

on the firewall near the HVAC box.





on the driver's side core support, looks like a relay?


Looking better, "good from afar, but far from good"

[marvgarr68]

that box you called a relay is the voltage regulator for alternator. You might have a internal regulated alternator on it no picture of it so can not be sure. The wiring by the heater box I am not sure I tore it all out of my 71 c20 I had got ride of all the extra wiring.
And looks good nice truck

[Zeke's Garage]

I can see that someone 'fixed' a 'heat soak' problem by installing a Ford type solenoid on the passenger fender. If you're looking to clean up the electrical mess, you can start by removing that solenoid and making sure your main battery cables are clean and tight, and that your starter solenoid wire (should be purple) is in good shape going to the starter. The small relay/solenoid on the firewall almost looks like a relay for a later model emission 'anti dieseling' feature, but can't even imagine why it would be there. What's it hooked up to?

Also any wire that has black electrical tape 'insulating' a splice or worse yet, hiding a wire nut or two, needs to be replaced with a new run. Those kinds of fixes will oxidize and turn into high impedance gremlins in just a few years.

The wiring on these trucks are dead simple. Get the colorized wiring diagram (It's around here someplace, I'll attach it if I can find mine) and go through each circuit from the bulkhead connector to the device and clean up one thing at a time. You'll have it cleaned up (and less of a fire hazard) in no time.

Good luck!

Shawn

[ericjon262]

Originally Posted by Zeke's Garage

I can see that someone 'fixed' a 'heat soak' problem by installing a Ford type solenoid on the passenger fender. If you're looking to clean up the electrical mess, you can start by removing that solenoid and making sure your main battery cables are clean and tight, and that your starter solenoid wire (should be purple) is in good shape going to the starter. The small relay/solenoid on the firewall almost looks like a relay for a later model emission 'anti dieseling' feature, but can't even imagine why it would be there. What's it hooked up to?

Also any wire that has black electrical tape 'insulating' a splice or worse yet, hiding a wire nut or two, needs to be replaced with a new run. Those kinds of fixes will oxidize and turn into high impedance gremlins in just a few years.

The wiring on these trucks are dead simple. Get the colorized wiring diagram (It's around here someplace, I'll attach it if I can find mine) and go through each circuit from the bulkhead connector to the device and clean up one thing at a time. You'll have it cleaned up (and less of a fire hazard) in no time.

Good luck!

Shawn

The relay on the firewall didn't appear to be hooked up to anything. I need to trace it back better though.

I Already have a new battery cable to fix the "fix" the PO did for me. I plan to re-wire the whole truck (as you said, it's dead simple) and intend to incorporate a few modern touches,

Electric Fans
headlight relay
electric fuel pump/EFI
A/c

all in a nice little relay center like the late model trucks have. thankfully, I'm not new to wiring, this will be a walk in the park compared to my Fiero's engine swap harness.

my favorite part that you can't see, is the 4 Ga wire connected to B+ and run through the firewall with no grommet or protection...

[ole dollor]

the relay next to the heater box is the high blower relay. the two wires you were holding in your hand look like old wiring for temp and or oil gage for dash light warning ( idiot light) . yours prop. has mechanical gages in it now.

[ericjon262]

Originally Posted by ole dollor

the relay next to the heater box is the high blower relay. the two wires you were holding in your hand look like old wiring for temp and or oil gage for dash light warning ( idiot light) . yours prop. has mechanical gages in it now.

the gauges appear to be stock, oil pressure is mechanical, temp is electric. I'll just have to find a diagram and trace them back and see. hopefully I can do that this weekend. if anyone has the diagrams available, I'd love to see them so I can familiarize myself with the colors.

Thanks-

Eric

Edit:

Anyone have a P/N for radiator hoses? I remember looking ages ago, and not being able to find one that fit properly.

[ole dollor]

the wires came in all the custom pickup wiring harness, whether it was light or mech. gage. the one that has something plugged into it looks like the top off of an old sending unit, it would have been plugged into the passenger side of the block to the rear, if yours is the original motor the other part should still be there in one of the water jacket plugs....

[ericjon262]

Originally Posted by ole dollor

the wires came in all the custom pickup wiring harness, whether it was light or mech. gage. the one that has something plugged into it looks like the top off of an old sending unit, it would have been plugged into the passenger side of the block to the rear, if yours is the original motor the other part should still be there in one of the water jacket plugs....

not the original engine, this one is an older 327 block with vortec heads.

[ericjon262]

The box on the core support is most definitely the voltage regulator, the one on the firewall is still unknown. I assume is was something to do with emissions, or the choke, there's one green wire(which gm usually uses for temp sensors) a blue wire, a black wire, and a red wire. the red goes to the firewall just to the left of the master cylinder. I'm going to get a multi-meter(need to buy a new one) and check for voltage and see if it's hot still.

[SCHRUMGMC]

Only thing I'd change on that is the Side markers

[ericjon262]

Originally Posted by SCHRUMGMC

Only thing I'd change on that is the Side markers

as in delete them? I like them, I think the truck would look weird without them.

[SCHRUMGMC]

No, heck no ...I mean like Deluxe Markers

[ericjon262]

Originally Posted by SCHRUMGMC

No, heck no ...I mean like Deluxe Markers

I'm gonna stick with the plain ones and maybe throw some LED's in.

[SCHRUMGMC]

Okay, I just love the Deluxe look

[OhioDan]

If ya squint, from a distance you're truck looks familiar? Welcome to the boards from Ohio.

[ericjon262]

uhhh... ****! well, no more radio for a bit, PO did a real great job with that! along with the tachometer wiring...

I'm tempted to go ahead and just but a new interior harness at this rate. the engine harness will be redone either way, so that's no biggy...

[ericjon262]

Originally Posted by OhioDan

If ya squint, from a distance you're truck looks familiar? Welcome to the boards from Ohio.

nice looking truck! 3/4 or 1 ton?

[OhioDan]

It's a 3/4 ton. Bought it down in Texas while I was there back in 84-85.

[ericjon262]

presenting plug number 4



and plug number 6



looks like I have a reason to start on the engine swap.