Cluster wire diagram

[Wahugg]

Hey all!

I have an 04 trailblazer, and as we all know the tire size can not be changed through the PCM for the 02-05 years. So instead I bought a spedo modifier that changes the signal from the PCM and modifies it to make the spedo either read slower, or in my case faster. The only catch is I don't know which wire is the spedo signal wire, so I'm wondering if anyone has a document listing the output of the connectors that go to the cluster. As a last resort I can break out the multi-meter but I'm hoping to save some time.

Thanks!

-Wahugg

EDIT:

I found the pin out after digging through the Service manual. It's pin B9 which is the dark green and white wire. Keep in mind this diagram is for the 04 GMT360, the wiring could have changed from previous years or future years.

[navigator]

Wallace, let us know how this works for you, I expect some of the guys with the older TB's will be interested.

[dirty anton]

PG 3 truck discussion,midway down,it says (abbots speed corrector after pcm), you may be interested

[v7guy]

For the lazy... viewtopic.php?f=32&t=2852


Anybody happen to know if the odometer pulls its signal from the speedo?


Mike, I take it it's still workin fine for you?

[dvanbramer88]

I don't know how it works on the TB's but i thought about the same thing on my truck as my speedo is off. On they highway, my odometer and tripometer are dead on using mile markers as a guide. I'm guessing they use the front wheel speed sensor and the speedometer uses the transmisson/transfercase output sensor. This is all based off of, When i spin the rear wheels, the speedometer displays the wheel speed from the rear, but the odometer doesn't move any faster and seems to be based on actual vehicle speed.

[Wahugg]

The unit I am using is being shipped all the way from down under (Australia) so it won't be here for about two weeks. Maybe even longer with the holiday shipping. The total cost was about $55 dollars, but the unit requires FULL assembly. This means soldering the all the components to the board. It may seem daunting, but as long as you can read a diagram and solder, it will be pretty easy. I am picking up a project box for about $4 from radio shack to house the finished board to ensure nothing will be shorted out.

I'll post a full review and overview once it arrives and is assembled.

-Wahugg

[dirty anton]

For the lazy... viewtopic.php?f=32&t=2852


Anybody happen to know if the odometer pulls its signal from the speedo?


Mike, I take it it's still workin fine for you?

yea it's bin working fine since the spring

[chevycrew]

Based on the fact mike and I are only running the t-case output speed sensor, I would venture to say that's where the speedo and odo signal comes from.

[Nakashige]

I agree with that statement as well Steve

[Wahugg]

Well the package finally came in, exactly 36 days later....

Anyways the package came with 4 sets (2 green, 1 red, 1 black) of wire, a bunch of electronic parts, a detailed instruction and theory of operating packet, and a circuit bored its self.


^Work Station


^Partially completed


^Fully completed

I hooked up 12v power and the led came on, and then after two or three seconds it went off.... Hopefully I did infact solder everything correctly and there are no short circuits. We'll find out tomorrow when I tear apart the dash and hook everything up!

I'll scan an attach the documents when I get off of work and home to my scanner.

Cheers!
-Wahugg