How To Convert From An Idiot Light Instrument Cluster To A Gauge Instrument Cluster

Contributors:  Xtremeclonedss, 80 Mich Bu and Malibuplotter

If you would like to change out your plain speedo and cluster to a cluster with a round speedo and tach, there is no need to remove your wire harness, this is a painless procedure! No need to pass any additional wires through to the engine compartment!  See below for simple instructions:

1.Remove cluster bezel and don’t forget the 4 screws on the bottom and 2 on the sides
2.Remove cluster lens and “PRNDL” indicator.  Carefully remove the push-on “PRNDL” cable from the column shroud.
3.Remove the cluster.  The cluster connector will stay with the dash pad
4.Using a very small screw driver, release each wire one at a time from the long speedo plug and place it in the correct numbered position on the plug for the round guages.  Going from the long speedo to the round speedo you will have two wires left over. I just taped them so to not cause any grounding problems and left them alone out of the plug.
5.Now put them back according to the diagram (below) marked “Round Speedo With Gauges”.
6.OK, you’re done inside the car.  Re-install the gauge cluster onto your dash pad.
7.Remove the brown wire from your alternator.  If you have a cluster WITHOUT a tach, just coil it up and tape somewhere under the hood – DO NOT CUT IT OFF!
8.If you DO have a cluster with a tach, I recommend tach filter (GM# 14062505) from any GM dealership or off any Cutlass, Monte Carlo, Regal, El Camino or Bonneville (1978-1988) at a junk yard.
9.Change your water temp and oil pressure sending units (for gauges).  You can get them off the above mentioned cars in a junkyard or a GM dealer.
10.Amp gauge is already OK
11.You’re done!!
LONG SPEEDO
WITH IDIOT LIGHTS
1ORANGEHORN, DOME, CIGAR 18GRAYCLUSTER LIGHTS
2YELLOWSEAT BELT LIGHT 17TANOIL LIGHT 
3DARK GREENTEMP LIGHT 16TAN W/WHITELOW BRAKE LIGHT
4BLANK15PINK W/BLACKIGN / ACC TEST 
5PINK W/BLACKIGNITION HOT14BROWNALT LIGHT 
6PINKFUEL SENDER 13DARK BLUERIGHT TURN SIGNAL
7LIGHT BLUELEFT TURN INDICATOR 12BLACKGROUND
8LIGHT GREENHIGH BEAM 11
9GRAYCLUSTER LIGHTS 10
ROUND SPEEDO
WITH GAUGES
18ORANGECLOCK 1BLANK
17WHITETACH / DISTRIBUTOR2TANOIL GAUGE 
16PINK W/BLACKPOWER ALL GAUGES3DARK GREENTEMP GAUGE 
15TAN W/WHITEBRAKE LOW LIGHT 4PINKFUEL GAUGE 
14DARK GREEN W/WHITECHOKE5GRAYILLUMINATION 
13YELLOWSEAT BELT6LIGHT BLUELEFT TURN INDICATOR 
12LIGHT GREENBRIGHT BEAM INDICATOR 7BLANK 
11PINK W/BLACKIGN / ACC TEST 8DARK BLUERIGHT TURN INDICATOR
10 9BLACKGROUND 
%d bloggers like this: