Gnx style dash Conversion

Joined
May 21, 2017
Good evening everyone I’m getting ready to swap out my digital dash to a gnx styl dash and I’m wanting to know what is involved in getting everything to work I know the obvious to get the boost gauge and others to work but I’m in sure about the fuel and tach and how the harnesses are
 
the avc/ poston/ quality engineer and precision instruments kits are similar and they followed the gnx design and install when thev built them. they had a plug that just slipped over the oe cluster main harness plug and then tape over and ziptie to keep together ,
the tach lead wire was run direct to the connector under the hood behind alt , (if you had analog you could run to that connector in the dasg but you dont have that connector with digital)

the oil pressure gauge replaces the idiot sender and the output from oil sender is tied to the oil idiot wire that you unplugged ,, this completes the feed to the new cluster
the water temp just replace the coolant idiot lamp switch in the intake with the new sender and connect the old wire to the new sender

the digital has two main connectors (analogs only have one) and to make it plug and play requires some additional wiring to be jumped from the smaller cluster connector to the main connector

if you didnt get one already cut up with the gauge setup youll need to cut out your cluster backer plate (the black plastic behind gauge cluster) to make room for the new cluster gauges
once the backer is out remove the flat plastic wiring harness protector and tape the wires up to protect from rub through
then need to drill a hole through the vent duct behind gauges and sleeve it for the new upper speedometer cable
then if you dont have a bezel already cut youll have to cut yours out and install the plexiglass lens (hope you have the preped bezel or the lens because you wont find one )

lastly youll need to connect the new upper speedo cable and inline vss sender under the hood and run the wires to the oe vss buffer (cut optic end off) ..hope you have that vss sender or you wont have cruise or lockup without it and they arent easy to get these days , if you have XFI there are ways to get the vss for the lockup but you wont have signal for cruise .
 

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the avc/ poston/ quality engineer and precision instruments kits are similar and they followed the gnx design and install when thev built them. they had a plug that just slipped over the oe cluster main harness plug and then tape over and ziptie to keep together ,
the tach lead wire was run direct to the connector under the hood behind alt , (if you had analog you could run to that connector in the dasg but you dont have that connector with digital)

the oil pressure gauge replaces the idiot sender and the output from oil sender is tied to the oil idiot wire that you unplugged ,, this completes the feed to the new cluster
the water temp just replace the coolant idiot lamp switch in the intake with the new sender and connect the old wire to the new sender

the digital has two main connectors (analogs only have one) and to make it plug and play requires some additional wiring to be jumped from the smaller cluster connector to the main connector

if you didnt get one already cut up with the gauge setup youll need to cut out your cluster backer plate (the black plastic behind gauge cluster) to make room for the new cluster gauges
once the backer is out remove the flat plastic wiring harness protector and tape the wires up to protect from rub through
then need to drill a hole through the vent duct behind gauges and sleeve it for the new upper speedometer cable
then if you dont have a bezel already cut youll have to cut yours out and install the plexiglass lens (hope you have the preped bezel or the lens because you wont find one )

lastly youll need to connect the inline vss sender under the hood and run the wires to the oe vss buffer (cut optic end off) ..hope you have that vss sender or you wont have cruise or lockup without it and they arent easy to get these days , if you have XFI there are ways to get the vss for the lockup but you wont have signal for cruise .

Thank you looks like I have my work cut out for me but I’m looking forward to getting this set up in I really appreciate all the info


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Install a brass T so you can use both the oil pressure idiot light and the new oil pressure gauge.
 
Install a brass T so you can use both the oil pressure idiot light and the new oil pressure gauge.

Good idea the previous owner removed the sensor to install the tubing for the gauge I believe I have the sensor


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Shouldn't be any tubing as the idiot light is electric, as is the new vdo gauge.
 
Shouldn't be any tubing as the idiot light is electric, as is the new vdo gauge.[/QUOTE


I understand that part but the person who had the car before me remove it and ran tubing for the gauge that is in the car now so I will have to put the sensor back in with the tee like you said


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Install a brass T so you can use both the oil pressure idiot light and the new oil pressure gauge.
why?? he wont have an oil idiot lamp in the new cluster , the gnx didnt keep the idiot sender either
 
And, factory oil sending unit with factory wiring will allow the fuel pump to work if the fuel pump relay on the fender should fail.
 
Some of the VDO fuel level gauges require a special tank sender that is hard to find and expensive. Check the part number on the gauge.
 
The digital dash has a 0-120 ohm sender for the fuel level. Analog has 0-90 ohm.
 
with digital (0-120ohm) or analog (0-90ohm) empty is 0 , with digital hanger a 0-90 ohm gauge will read full when tank is at 3/4 full , as it runs down the gauge is off less....not really an issue .
simple fix if it bothers you is get a 0-90 hanger
 
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with digital (0-13-ohm) or analog (0-90ohm) empty is 0 , with digital hanger a 0-90 ohm gauge will read full when tank is at 3/4 full , as it runs down the gauge is off less....not really an issue .
simple fix if it bothers you is get a 0-90 hanger

Ok [emoji1417] thanks for the info


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GNS Performance makes a kit for around $1500 with newer gauges that is plug and play. I have an old Poston dash with VDO gauges and idiot lights. It has an electronic speedo vs mechanical so I used a dead end sender from Summit Racing and a Caspers converter box to the original buffer. With the stock ecm lockup wouldn't work so I used a manual switch. After converting to XFI the lockup works like it should, but I have never tried the cruise.
 
with digital (0-120ohm) or analog (0-90ohm) empty is 0 , with digital hanger a 0-90 ohm gauge will read full when tank is at 3/4 full , as it runs down the gauge is off less....not really an issue .
simple fix if it bothers you is get a 0-90 hanger

This is interesting? I bought a car with the GNX VDO gauges and had to replace the sender, I installed the 0-90 ohm unit not knowing the difference at the time. It reads beyond full with a full tank and empty around 5/8 tank?

Any ideas what would cause this if 0 ohms is empty? I was thinking it was the other way due to the way it was responding?

I just looked up the VDO gauge specs it is a 10-180 ohm and it does say 10 ohm should be empty? Very strange? Any way that is the sender I was pointing out is hard to find and expensive.
 
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