New here.
...and stuck at figuring out why I can’t get headlights/tailights.
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 back 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.
Thank you for any and all advice.
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?
I don’t know exactly what I’m going to do just yet but very eager to complete this project.
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 --
