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Claudio 08-20-2017 02:51 PM

Digital dash help
I'm getting ready to do a digital dash transfer......
Doner car 88 GTA with digital dash and SWC's
My car 1991 convertible Trans Am
What do I need to know about getting the digital dash and harness out....?
Wireing diagram for the digital dash....?
Thank you

merc3065 08-24-2017 03:19 PM

Re: Digital dash help
You will need the entire wire harness from behind the dash that goes to the C100 connector on the upper left hand side of the firewall.

The dash frame may be needed, but I don't know if Pontiac changed the frame to fit the gauges or not. In the 87-89 it was not needed as these were the years for the digital gauges.

If you are transferring all of the Digital Information Center components, you will need the full lighting harness (front, rear and fog light) as well as the door lock sensors for the doors and rear hatch.
The light harnesses are resistance matched and the DIC picks up the resistance changes to determine if a light is out or not.

The sensors that go into the doors are connected via a thin grey/grey lined-black wire and are "clicky" type in nature. They look like the pressure sensors from a mouse (have a little metal arm clicker that trips the sensors).

Otherwise you will never get the read out to say "PONTIAC OK" and it will always say your lights are dead, hatch and doors are open.
The Digital Info Center (DIC) also contains your odometer so it will not be matched to your original mileage on your analog setup.

If you are transferring the electronic heater controls you will also need the heater core, digital A/C controls, and the wiring harness for the blower motor as they are different from the analog controls.

Finally, can't say if it will work with the 91-92 ECM or not. In theory it should, but no clue if the speedo and rpm are controlled differently than in the 87-89.

bob2002gtp 08-24-2017 05:46 PM

Re: Digital dash help
The digital dash was also available as an option in 1986, but the tach was slightly different. The ECM uses a different connector for the 90-92. 1986-1989 should be the same connector for ECM 1227165.

Claudio 08-24-2017 11:34 PM

Re: Digital dash help
Can I keep the 91 ecm with the 88 digital dash.....??
Any one have wireing diagrams for either car....??
Thank you

merc3065 08-28-2017 06:47 AM

Re: Digital dash help
Go to google
Type 88 firebird PDF
Click on the link
In the upper right corner you can either browse or try to download it.

Section you are looking for is the electronic dash.
It has some wiring diagrams but not all.
For some more wire diagrams, try to locate the body manual for the 88.

Chiltons and Haynes guides have some more info.

Claudio 09-15-2017 08:29 PM

Re: Digital dash help
Ok I have the ecm from the 88 GTA
Can I use it to run the 305 TPI in the 91 trans am convertible....??
Is the a/c box different from digital to non digital...?
From 88 to 91.....??

bob2002gtp 09-17-2017 09:20 PM

Re: Digital dash help
AC box is different. The heater controls are push button and work with the actuators.

merc3065 09-19-2017 03:28 PM

Re: Digital dash help
You cannot use an 88 ECM to run a 91 TPI.
The 2 are completely different sensor setups.
86-89 are mass air flow sensor.
90-92 are speed density sensor.

That link is perfect and has loads of pictures to refer to.

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