[Colin W]

Hello all,

Sorry to beat a dead horse with this topic. I'm struggling to find the correct info to make the swap; different rally gauges are available, and it's hard to tell what exactly to follow. I'll attach some pictures below of my gauge. Any guidance is helpful. I'm also installing a factory-style dash tach as well.

Thanks in advance guys.

[Colin W]

Pictures via mobile will not upload. I will attach them later when I get home.

[backinhs]

Credit goes to Pete Serio:

There are 3 differences between a dash harness for a 71 GTO or Lemans with gauges and one w/o.**The conversion from red warning lamps to rally gauges is fairly easy.*

·*********Locate the black plastic plug which connects to the printed circuit on the back; you need to remove and exchange places with just 2 wires.*

·*********Remove the tan #5 wire & put that into the**#7 location.**While at the same time removing the (brown) wire that was in #7 and put that in the #5 space. After that your almost done except for one more very important thing.*

·*********As a red warning lamp harness the temperature (dark green) wire runs from the back of the cluster to the temperature overheat switch.**On non-gauge cars only; in-between the gauge and the sender the dark green wire forks over to the ignition switch and then doubles back.**Your ignition switch is bolted onto the top of your steering column up underneath the dash.**You need to get to the ignition switch (drop the column), un-plug the master plug and remove the twin dark green wire(s) from that large plug.**DO NOT CUT THE GREEN WIRE(S)!!!**Simply unplug the connector and remove the brass spade which has attached to it TWO dark green wires.*

·*********After removal you need to just tape over the brass leaving the 2 dark green wires intact.***Plug your master ignition switch back in and bolt the column back up.

*This completes the wiring modifications at the dash.

*

Change out the sender units for oil pressure*and*coolant temperature*that I give.

*

As for the tachometer this is*fairly easy.*You need*switched 12 volts (key on) directly from the fuse block via the red wire I made It has a built-in*2 amp in-line glass fuse.*

·*********Run the second lead from the rear terminal on the*tach to the negative side of the coil and your good to go. You*power for those*two lamps that plug into the*tach for nighttime*lights.

·*********If your car has a clock in*it now use that same*wire loom to light up your new tach.**If not it can be ordered from any of the Pontiac parts suppliers for a small amount of $.* There is a gray wire take-off pre-built into main dash harness on all cars which you plug into for the tachometer's wire loom lights.



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[Colin W]

Here are the pictures of my rally gauge. Doesn't sound like a lot of fun; I hate anything wire related!

[backinhs]

No wiring needs to change on the gauges. Read the 1st 3 points above.

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[Colin W]

I'll attempt to follow your guide. Hopefully I won't struggle too much with the installation. Thanks!

[West Coast GTO]

I am interested in changing from idiot lights to gauges; where did you purchase you Rally gauges from?

[backinhs]

http://precisionpontiac.net/

[UPC-WU2]

This might help:
http://www.gt-37.org/gallery/main.php?g2_itemId=3362