Wiring

[fabjunkie]

Can anyone tell me what this is?

I found it wrapped up in a bundle of electrical tape (like everything else so far) and have no clue as to what it is for. The little black box plugs into the "card". I've lost my turn signals so far, although I have some other stuff unhooked.

Does anyone have a wiring schematic they can post or email me that I can print out? I hate not being able to trace sh!t through wire looms.

 

[dontoe]

Mini-thermonuclear device?

 

[fabjunkie]

Lol...The black box has "made in canuckland" on it so I thought it might be aftermarket trailer brake wiring or something, but it runs up into what appears to be factory looming. I've just never seen a circuit board exposed like this from the factory. I just realized that this truck does have the "Trailering Special" package, so it may have something to do with that. I'm not even far into this thing and am already contemplating ordering a painless kit.

I did a search and came across MuddyTazz's wiring schematics on his webshots page, but when I print them out, I can't make out what is what. What's a good book for the diagrams? From what I gathered from the search, Chilton's suck. I've always like haynes better anyhow.

 

[Cmoe]

a few things:
What year?
Where is this at (location)?

 

[dyeager535]

I see the gas/brake pedals and the wiper connector, so it's gotta be right around the steering column.

First guess was the convenience center (handles horn, etc) but that has a different wiring configuration.

I don't think GM would have done something like that from the factory, but a dealer may have.

 

[1985_K5_Silverado]

What does that large black box have printed on the side? Is it a relay?

 

[fabjunkie]

Yeah it was hanging on the right side of the steering column. I found the bottom half of an enclosure for it attached to the right side of the column, about half way between the firewall and dash. The outer cover is missing, so I stuck it back in there and zip tied it in. The black box just says "made in Canada" with a couple numbers. Looks like the one might be "33R" from the pic I posted above. I'm not sure if it's a relay or not. I was thinking that too though. It does appear to be factory though. The way it's wired into the main harness doesn't appear to have been a dealer doing.

The turn signals not working were the result of a flasher going bad, so no biggie there.

 

[goldwing2000]

Might be helpful if we knew the year, make and model of what you're working on.

 

[fabjunkie]

Oh yeah, sorry. It's a '77 K5. Guess I need to set up my sig.

 

[goldwing2000]

In that case, I would venture to say it's definitely something aftermarket.
Computer chips didn't make their way into vehicles until MUCH later.

Possibly some sort alarm or remote starter. Looks like it has too many wires to be a trailer brake.

Take the wire loom apart and see where it goes!

 

[fabjunkie]

I didn't pay any attention to the fact that that chip was there until you said something. Damn, now I'm going to have to tear it apart.

 

[goldwing2000]

LoL... that was the first thing I noticed.

Any time you have a PCB with that many resistors, you can bet there's a chip in there somewhere!

 

[AZ79K5Project]

I also would guess some home grown thing. The transistor that is bent over is probably suppossed to be attatched to a heat shield.

You may want to do a couple of tests:

See if there is any power to it under different conditions.
Use a Volt Ohm meter and a test lamp.

Check to see if it has power with key off and on?
Check to see if power with brakes or signals operating?
Does it have multiple power sources and multiple power outputs?
You should be able to narrow down the circuits it touches by this method.

Type in the number that is on top of the IC into Google. It looks like it starts with MM by the pic. You should get an idea of what the IC does or post all the letters and numbers and I can see what I can find.

It looks like to type of remote switch or flasher

Are there any switches mounted that don't seem to do anything?

 

[BobK]

Might be a day-time running light modual.
That's alot of wires going to and from that thing though.