Overhead console temp/compass upgrade

[truckin 79]

Has anyone done this with a s-10 blazer overhead console that has temperature and compass? I bought one from the junkyard for 12, it is one of the short ones. I know there is a sensor probe somewhere in grill that I forgot to get. Does compass need any special wires or sensors I need to get? I like the over head lights,compass and temperature features. I looked in past posts but did not really see any explanation of wiring hook up. This is the type I bought do not have it hooked up yet.

[Palf70Step]

Looks like a neat Idea. Off hand I don't know anyone who has done it, but it looks interesting for sure.

[Bloodhound]

Originally Posted by truckin 79

Has anyone done this with a s-10 blazer overhead console that has temperature and compass? I bought one from the junkyard for 12, it is one of the short ones. I know there is a sensor probe somewhere in grill that I forgot to get. Does compass need any special wires or sensors I need to get? I like the over head lights,compass and temperature features. I looked in past posts but did not really see any explanation of wiring hook up. This is the type I bought do not have it hooked up yet.

I've seen (and intend to do) a rear view mirror with the temp, compass, and map lights. but haven't seen the overhead console done.

[hatzie]

This is the pinout from the second generation Jimmy.



You only need four of the wires populated for compass and temp display.
Battery power, Ignition power, Ground, Temp sensor, and Dome/Courtesy Lamp.
GM wired the temp sensor as a loop from the console ground on one side, through the sensor, and back to the console TEMP sensor terminal on the other. I would feed the ground side of the temp sensor from the ground pin on the console just like GM did to avoid ground potential differences. Ground is not always ground... If you pick up ground off the rad support or somewhere else it may not be the same potential as the ground on the console. This will throw the temp reading off.


You'll need a serial data connection to a compatible PCM & the VSS signal to make the trip computer work if your console has one.

[68PanelTruck]

Originally Posted by hatzie

This is the pinout from the second generation Jimmy.

Attachment 1975817

You only need four of the wires populated for compass and temp display.
Battery power, Ignition power, Ground, Temp sensor, and Dome/Courtesy Lamp.
GM wired the temp sensor as a loop from the console ground on one side, through the sensor, and back to the console TEMP sensor terminal on the other. I would feed the ground side of the temp sensor from the ground pin on the console just like GM did to avoid ground potential differences. Ground is not always ground... If you pick up ground off the rad support or somewhere else it may not be the same potential as the ground on the console. This will throw the temp reading off.

Hello Hatzie,
I am trying to do this same mod on my 68 Panel. I have an overhead console out of a 98-04 Blazer/GMC/Bravada. It has the compass and temp (no trip odometer or MPG functions) It has two electrical connector plugs, one that feeds the dome lights that I will have to install door switches to turn on and off. I believe the console is identical to the diagram you posted above.
The other connector plug has 6 wires that match the colors in the diagram pins #5, #6, #7, #8, #9, #10. (W/O trip computer)

#5 Dark green
#6 Black w/White
#7 Dark Green w/White
#8 Lite Green w/Black
#9 Gray
#10 Purple w/White

I think I understand most of what you said.
Can you confirm please?

Pin 5 is fused ignition (hot when the key is on?)
pin 6 is ground
pin 7 is VSS in (vehicle speed sensor I believe? Don't have that, it's a stock 68 c10. Do I leave this unused?)

pin 8 is air temp. I bought the matching ambient air sensor and it should connect to this pin on one side and ground on the other.

pin 9 is INT (instrument?) light dim. This is where I am confused. Is this to dim the digital display? I don't really care if it dims or not so do I leave this unused or does it have to be connected? If so, to where?

pin 10 Parklamps and interior light system. Not sure where to connect this one either.

So that is 6 wires/pins and you said that only 4 are needed, Battery power, ignition power, ground, temp sensor and dome/courtesy lamp.

Battery power pin #??
ignition is pin #5
ground is pin #6
temp sensor is pin#8
dome light is pin #??

So what I really need to know is what pin is battery power and what pin is dome light and is the dome light wire hot only when the dome light is on?

I really do appreciate any help you can give me. Thanks,
Robert

[hatzie]

You only need VSS when you have the serial data from an ECM/PCM of the correct generation to run the MPG calculations. I doubt the compass uses this wire. I'd leave it as stubbed off pigtail with some heatshrink over the end. Leave enough wire to attach it to a wire from a VSS if needed.

INT Lite DIM #9 is a feed from the instrument panel lamps to dim the digital display depending on the voltage level from the headlamp switch. Fun but strange fact the 73-91 squarebody trucks used Gray for the instrument panel lamps.
The parking lamps no doubt signal that the nighttime lamps are engaged so the display dims somewhat with additional input on how far to dim from the instrument panel lamp wire. The 73-91 trucks have at least one unused position on the headlamp switch plug and switch that's tied to the parking lamp circuit.

Fused BATT is #14 Orange

The swiveling dome lights are wired separate to the dome lamp wiring on the 90's & 2000's trucks as far as I know. The dome in your cab is fed fused battery voltage all the time and a switched ground from the doorjamb and headlamp switches. I would pull the ground and power wires for the two lamps in the console from your dome on the back of the cab ceiling. You can probably use the dome lamp power for #14 on the compass/temp module.

[68PanelTruck]

Thanks. I only have six pins (5-6-7-8-9-10) and no orange wire (or yellow). I guess I'm confused because you said both battery and ignition power. I don't have an orange wire for Batt power. I believe the console with the trip computer would have an orange and yellow wire but I have the console with temperature and compass and no orange or yellow. Would it get is power from pin 5 (dark green)?
BTW, if I put 12 volts on the ground and pin 5 the display lights up and shows a steady 95 degrees (only about 50 here in the shop) and NW on the compass. I do have the temp sensor wired. I'll have so wait till the truck is drivable to test the compass. I read somewhere that the temp can be off because it uses the VSV to delay reporting until the car is moving to avoid reporting an artificial high temp due to heat soak while parked. Thanks again for your help.