Hey gang - 88 GTA digital dash. I would like to connect a custom-made external digital speedometer separate from the dash itself. I received the Speedo board in the mail the other day and it works fine on my friends Thirdgen when spliced directly into the Speedo wire coming into his harness. But when I try to do the same thing on mine, the speedo doesn't work (just always reads zeroes). Does anyone have any suggestions? I'm thinking it's got something to do with my digital dash vs. his stock guage one, but can't say for sure. Thanks for any assistance you can provide.

 

With the D-dash, the VSS goes to the processor contained in the dash.

To run the analog-look speedo, you need to use a buffer.

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Happy Racing!

 

Thanks Nina! Not sure I'm familiar with a buffer or how it's installed. Can you assist there? Or, would soldering directly to the wire on the PCB solve the issue?

 

Quote:

would soldering directly to the wire on the PCB solve the problem?

That might work if it doesn’t load the circuit to the existing speedo.

You might have to use a buffer to prevent loading.

You can use a buffer from a salvage yard car, or use an integrated circuit.

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Happy Racing!

 

Is there a way I can see if my car currently has this 'buffer' already? Someone mentioned he's almost positive it does already. I don't know what they look like or where they are located, so if you can guide me in the right direction on where I could look, that would be great. My car is an 88 GTA 350 5.0 L V8 TPFI THANKS!

 

All the circuitry in the DD is being used for the DD.

Trying to tap it to run a second speedo might cause damage.

Therefore to run the second speedo get a buffer and tie it to the VSS.

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Happy Racing!

 

Thanks Nina. I got that part. Not sure if you understood my question though (see below). Where can I look in my car to see if this buffer already exists? Do you have any pics of what it looks like? Thanks again for your help!

 

The buffer is behind the dash on cars with the L03 engine + analog dash.

On cars so equipped the buffer, usually a yellow case, is behind the dash on the right.

It has 2 connectors.



Other cars use the ECM.

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Happy Racing!