How to: Install DIC in gmt400 overhead console

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Chris8393

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WE HAVE COME TO THE CONCLUSION THIS DOES NOT WORK ON DEISELS

What you need.
-DIC out of a blazer, a long console DIC has the compass built in
-wire of your choice (I used 6 conductor phone wire)
-temp sensor
-I used 7 feet of wire from DIC to Radio I would suggest using about 8 feet
-9 feet of wire to the temp sensor


Ok here is how I did it.

I started by removing the screw on the front of the OHC so I could slide it forward to release it from the roof
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then unplugged the connector for the lights.

I then had to make my own wireing harness for it because I did not want to even try to get the factory one from the blazer.
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If you make your own harness make sure you take notes as to what wire colors go where.
I soldered all of my connections but if you don't know how or are no good at it you can use crimp conectors , but you have to make sure your connections are flawless.

Then take the dash panel off so you have acesss to the radio wires, and remove your radio.
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I ran the wire on top of the headliner and down the drivers side A-piller into the dash by the headlight switch under the cluster and then to the radio(most of your wires will be here.
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The wires you need at the radio are as follows
Pin #6 ppl/white------>LED dimmer
#11 grey------>Illumination circut power
#9 drk green---------> RAP fuse supply
#16 drk green/white ---------->VSS


I used the power and ground from the lights in the OHC.

The only wire needed out of the cab is the signal wire for the temp sensor. (lt. green/black)
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I tested the DIC before the temp sensor and the class 2 serial wire was hooked up thats why it reads (--)
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I put a piece of wire loom over the temp sensor so it wasn't easily seen behind the grill
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This is where I mounted the temp sensor using the factory clip from the blazer
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And this is where you hook up to the class 2 serial data
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Some finished pics.

Compass was not calibrated yet

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I have not figured out why the range mode always reads Lo

EDIT: I found out that for the RANGE mode to work the fuel level sender has to run thru the computer (96-97 does not) 98+ does.

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This is the only in operation pic I have
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I have a 2000 k2500 were do I hook it up to make the range work
 

Vince290

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The dice I got came out a astro van and my wires don't match, I have the 9 pin connector but mine only has 7 wires and none of them match the order or colors of the diagram you posted. I couldn't be more lost, I might just go find one that matches one day cause I can't even fathom anything with wiring and I have no idea what I'm supposed to do with this one

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AK49BWL

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The Astro Van DIC wire colors differ from the S10 variation, but the pin-out is the same. Based on the wire colors I'm gonna guess you got that from an 02+ Astro - Pinout is as follows:

Code:
P7  - Black   - HOT in Run or Acc
P8  - White   - Ground
P9  - Green   - VSS Signal
P10 - Ppl/Yel - Temperature Sensor Supply
P11 - Orange  - LED Dimming Sig
P12 -   Red   - Park Lamps Sig
P13 - N/C
P14 - N/C
P15 - Lt Blue - Class 2 Data

If it's the same size DIC as the S10 variant, I'd say you could still use it, the only difference is there's no "HOT at all times" line that would be on P14.
 
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lxe4

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Finally got my DIC in. No worky. 96 k2500 5.7. double checked my connections, tried jumping a VSS from the guage cluster and no different. The compass will no calibrate but started out saying NE or NNE. I also didn't have the temp sensor installed at the first test but still no joy. It shows c in the complass, what I would call an accurate temp for about a minute after startup, and shows 0.0 or something on the other parameters. after a minute or so compass says C everybody else says --. Dont know when Ill get a chance to hunt down some more DICs but has anyone that has had this error ever solved it? I see at least one example in the group but don't know what the outcome is. Thanks
 

AK49BWL

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-- generally means it's not receiving data from the ECM. Where did you splice the class 2 wire?

I'm guessing you have, but have you tried driving with it? If the engine is off in my truck, mine will go to dashes as well.
 

lxe4

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Yea same thing while driving. Hooked up to the purple wire on the diagnostic port. I also have a blackbear computor. My code scanner works though so I suspect that circuit is not shorted or anything
 

lxe4

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Tried my original engine computor and another dic. Still the same result. I tossed in a stereo head with the SCV feature and it functions, so the VSS circuit seems functional. I must have crossed up the class 2 wire. I hooked it to a rather large purple wire. Scan tool still functions as well.
 

AK49BWL

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Large purple wire could be a power line... All of the Class 2 lines are small diameter wires. If you hooked it up to a power wire, you most likely fried the Class 2 receiver in the DIC.
 

lxe4

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Tried my original computor. Got another DIC. Put in a stereo that has SCV and it works, confirming VSS is actually working. Still the same stuff. I do notice my 2 dics read the temp 5' different. The first one said 22 and the second says 16c. Anyone want to try testing one of these units I got in a known working vehicle? Or maybe sell me one that is tested and known to be working? Its still possible I got 2 dud units in a row.
 

Maroon96

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I've been having the same issue in my 96. Maybe it's just our trucks? Has anyone else with a 96 got this to work properly?
 
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