New here.

[AlaRado]

Greetings AlaRado,

Welcome to the GMT400 forum, where we all share your good taste in
this generation of the General's trucks & SUVs.

In order to shed a little light on your illumination woes, I fired up the '94
Driveability, Emissions, & Electrical Diagnosis manual and located the
Head Lamp wiring diagram, which is where we would start theorizing on
what's malfunctioning on your truck based upon the symptoms:

You must be registered for see images attach

(NOTE: Tail lights, turn signals, and marker lamps all on neighboring pages.)

Of course the above is drawn at the electrical abstraction layer. Fortunately the manuals
also include the wiring harness physical layout as originally installed on the assembly line:

You must be registered for see images attach

(NOTE: Important Head Lamp grounds circled. Bad grounds can create a real diva of a daily driver.)

I've also attached the first page of the non working Head lamp troubleshooting flows, just
to give you a taste of what's waiting for you in the FSMs. (Factory Service Manuals) They
don't cover all possible problems, but I find they do help get your head into a productive
troubleshooting space.

And since it looks like you are putting together something that someone else took apart,
I included the first page of the Lighting Connector listing. I find this helpful when trying
to identify a particular branch of a (new to me) wiring harness.




1) I'd like to echo what other members have already mentioned about downloading a set of
the Factory Service Manuals for your '94. By doing so, when you ask a question based out
of the FSM, us remote dudes scattered all over the globe can literally be reading from the
same page. If you haven't already done so, follow this link and take a lot of guesswork out
of your project: ('88+ GMT400 FSMs) Note: This is where I got the .pdf files I used above.

2) Consider turning this into a dedicated build thread for your truck. This way when you ask
a new troubleshooting question we can review the thread and have the proper context to
help frame the most suitable response. (As opposed to starting a new thread for every issue,
and we have to pretty much start over with what we're working on.) Here's a good example of
what I'm talking about: (Komet's K2500 Revival) Possibly a moderator could move this thread
to where these threads live?



Your actions support your statement. Anyone who is willing to put in the time & effort to
divert one of these machines from the scrapyard and back onto the road as a reliable daily
driver has instant cred with lots of folks in here. Keep fighting the good fight, and if any
more questions come up just post them in here and we'll give it our best.

Again, welcome to the forum, and nice to cross paths with you.

Cheers --

Thank you so much!

 

[registered-bum]

Welcome AlaRado - good work on that half ton already!!!

 

[AlaRado]

I would say picking up a project at that level of disassembly, you probably just have some ground wires that aren't connected. As docstoy mentioned, look at the sticky posts at the top of the Engines forum and you'll see one with the factory service manuals; they're free downloads. There's wiring diagrams in the electrical section and you'll see the locations of those grounds. For the headlights each side of the forward lamp harness has a ground that attaches at the core support. The rear lamp harness has a ground (maybe two) that attaches at a frame cross support near the end of the driver's side frame rail.

Looks like you got a lot of truck for $200.. and you've made a lot of progress so far!

Richard

Thanks! I saw the potential it had. I was skeptical at first but after setting up a time to meet and actually viewing it in person, I couldn’t pass the deal up! More pics to come as I make more progress!

 

[CumminsFever]

Man who buys a bag of bones and turns it into a live runner is very welcome here. Posting pics is the icing on the cake! You have great vision on potential, keep up the great work!

 

[jd33173]

Welcome, looking good and nice job so far!

 

[AlaRado]

Welcome, looking good and nice job so far!

Thanks!

 

[AlaRado]

Welcome, looking good and nice job so far!

Man who buys a bag of bones and turns it into a live runner is very welcome here. Posting pics is the icing on the cake! You have great vision on potential, keep up the great work!

Thanks!

 

[AlaRado]

Welcome AlaRado - good work on that half ton already!!!

Thanks!

 

[AlaRado]

I have a question about the engine before I dig into it. My buddy told me that it had been rebuilt previous to him purchasing it for his project. Long story short. He never ran it and when I put it in my truck I thought I could simply crank it and it wouldn’t turn over without me turning it over a couple revolutions with screwdriver on flywheel before each time cranking it. It seems freed up now but I hear a slight rubbing inside the oil pan. It’s more of a scrub sound and I really don’t want to admit it but I believe it may be something serious! What should I expect? I’m thinking to drain the oil and remove oil pan while engine is still installed in truck to inspect and hopefully just find something fell into the engine at the least. I crank it up maybe a handful of times pouring fuel in carb bowl and don’t believe I’ve ever let it run long enough to cause any damage but what do you guys think may be the issue I will find?

Backstory
*my buddy had purchased it from a friend of his after he had it rebuilt. He put it in his 59 Chevy truck project but never ran it. I bought it and installed it and noticed it was only turning over a quarter of a rotation before getting stuck. I got under truck and turned flywheel left and right attempting to get unstuck until I finally got it to turn freely. I now hear that rubbing in oil pan when it gets to a certain point of the crankshaft?!

 

[HotWheelsBurban]

I have a question about the engine before I dig into it. My buddy told me that it had been rebuilt previous to him purchasing it for his project. Long story short. He never ran it and when I put it in my truck I thought I could simply crank it and it wouldn’t turn over without me turning it over a couple revolutions with screwdriver on flywheel before each time cranking it. It seems freed up now but I hear a slight rubbing inside the oil pan. It’s more of a scrub sound and I really don’t want to admit it but I believe it may be something serious! What should I expect? I’m thinking to drain the oil and remove oil pan while engine is still installed in truck to inspect and hopefully just find something fell into the engine at the least. I crank it up maybe a handful of times pouring fuel in carb bowl and don’t believe I’ve ever let it run long enough to cause any damage but what do you guys think may be the issue I will find?

Backstory
*my buddy had purchased it from a friend of his after he had it rebuilt. He put it in his 59 Chevy truck project but never ran it. I bought it and installed it and noticed it was only turning over a quarter of a rotation before getting stuck. I got under truck and turned flywheel left and right attempting to get unstuck until I finally got it to turn freely. I now hear that rubbing in oil pan when it gets to a certain point of the crankshaft?!

If I were you, I'd check it out pronto. No telling what it may be,but your description doesn't sound good.