overhead console concern

[dixie1273]

ok i installed an overhead console in my 98 astro van with compass and temp gauge, well a friend of mine wanted one too so we went and got him an overhead and we installed it useing the factory harness, his overhead has compass temp and mode.. mode tells you mileage average fuel used, etc. when we first plugged it in i it gave us all kinds of information on the mode selection...thats great!!! But after about 2 minues, it zeros out, almost like it resets itself. the only thing that works after that is the compass. Everything on the display still lights it just shows zeros, or lines. Am i missing something for this overhead that i did not grab? Maybe a control module?? Also his van is a 96 safari and mine is a 98 astro, and we tried it in both vans and got the same results. any thoughts?

['cudapaul]

Yes, the advanced display features only work in the 99 and up models.
The reason is that the cabling that goes to the display has more wires and more information going to it, specifically the vehicle's serial bus. Without it, the module can not get the information to display the gas mileage, etc.

The info that you saw was from the last time it was operated in the previous van. When it tried to update it could not receive the data and went to zeros.

If you look at a factory manual for the 99 you can find the serial bus connection and wire that to the module.

BTW, I did get it to work in a 97 van, but I can't confirm that it will operate in a 96, but I don't think that there is any reason it wouldn't. Give it a try!

[GTZ]

Cool, Im having the same issue on my 97. Ill have to look into it now.

[dixie1273]

ok heres where im at, the advanced display feature harness plug has 7 wires, where the regular compass and temp harness plug has 6 wires, the 7 wire plug has an extra purple wire, i tried to follow where this purple wire goes and i didnt get very far, i traced the harness all the way back to behind the fuse block and the "purple wire" disappeared into a much larger harness. it appears that this is the wire i need to connect to get my advanced display overhead to work.

Does anyone know where this purple wire is going?? I traced this wire in a 2001 van, im assuming 1999 and up would be the same. Any input would be helpful.

[GTZ]

I think I found the purple wire:
http://econtent.autozone.com:24991/znet ... 227a7b.gif

[dixie1273]

so.... it looks to me like i just need to tap into the vcm?? am i reading this right>

[astrovan98]

By any chance, does anyone happen to know if the instrument cluster on a 1999 uses serial data communication instead of multiple gauge wiring?
My 1998 uses individual wires for each gauge. My 2005 5.3L Gen III engine (swap) uses a serial data dash cluster, and it is leading to issues for the gauges (additional sensors for oil pressure, water temp, fuel level). The biggest issue is the fuel gauge.

[DRZ]

By any chance, does anyone happen to know if the instrument cluster on a 1999 uses serial data communication instead of multiple gauge wiring?
My 1998 uses individual wires for each gauge. My 2005 5.3L Gen III engine (swap) uses a serial data dash cluster, and it is leading to issues for the gauges (additional sensors for oil pressure, water temp, fuel level). The biggest issue is the fuel gauge.

Do your anti lock brakes work ? My '98 had separate wires for the ABS, cruise, and something else (maybe odometer) but on the LS1 they all go to one place so that's how I wired the '98. Everything works except the ABS and of course the fuel gauge. I have continuity to the ABS but it's not getting the signal it expects I guess... Stan

[DRZ]

ok i installed an overhead console in my 98 astro van with compass and temp gauge, well a friend of mine wanted one too so we went and got him an overhead and we installed it useing the factory harness, his overhead has compass temp and mode.. mode tells you mileage average fuel used, etc. when we first plugged it in i it gave us all kinds of information on the mode selection...thats great!!! But after about 2 minues, it zeros out, almost like it resets itself. the only thing that works after that is the compass. Everything on the display still lights it just shows zeros, or lines. Am i missing something for this overhead that i did not grab? Maybe a control module?? Also his van is a 96 safari and mine is a 98 astro, and we tried it in both vans and got the same results. any thoughts?

I put an overhead console in my '98 as well but couldn't find any existing wires to make anything more than the lights work.

[sfeaver]

If you hook that remaining wire to the data line (the purple wire i believe) everything will start working. I tapped in mine right behind the ALDL port under the dash. My van is a 97, I did this about three years ago now and works great.

Scott

['cudapaul]

Scott is correct, the purple at the back of the OBD2 connector is the serial bus. Just tap into it.

The Instrument Panel from 96 to 99 is not ECM or serial bus dependent. Later model years are.

DRZ, not all vans have the overhead console cable. If yours is a cargo it definitely will not have the cable.
You can scrounge a cable from the wreckers ('99 and up) or make one. You can order the plastic plugs at the dealer and purchase the electrical pins at Napa or Pep boys, or any other location that sells that type. The cable does not need to be anything special, 9 to 12 conductors, unshielded is fine.