wiring aftermarket gauges for a gbody ls swap

[Moochie]

ok so im under going a ls swap in my 86 gbody and i have my harness broken down and my pcm reflashed and now i need my gauges wired up and working. im going to be using aftermarket but havent decided on what style so i would like to know how to wire a 6 gauge digital setup and a 6 gauge mechanical setup. Any info or links to do this would be very helpful,thanks
wiring up :
tach
speedometer
temp
oil
volts
fuel

 

[L92 OLDS]

ok so im under going a ls swap in my 86 gbody and i have my harness broken down and my pcm reflashed and now i need my gauges wired up and working. im going to be using aftermarket but havent decided on what style so i would like to know how to wire a 6 gauge digital setup and a 6 gauge mechanical setup. Any info or links to do this would be very helpful,thanks
wiring up :
tach
speedometer
temp
oil
volts
fuel

I used Dakota digital to make it easy. The Dakota gauge cluster for the Cutlass looks factory stock and has a lot of nice features like 0-60 time, quarter mile timer, speedometer reads up to 160mph and the tachometer reads up to 8K RPM.

This might help you:
Tach - use ECM tachometer lead. Check the harness pin out. Your tachomoter must be configured correctly for GM pulse
Speedometer - What transmission? Digital gauges require VSS pulse and must also be configured correctly. Cable or VSS? I have a cable to VSS adapter if you need one.
Temp - Add a separate temperature sensor for gauges only to passenger side head port. The ECM sensor is on driver side. Use sensor provided with gauge.
Oil - If you do not have oil cooling lines then drill and tap the oil cover block off plate at the oil filter location. My headers are too close to this location so I used a T fitting at the rear of the intake manifold. Use sensor provided with gauges
Volts - Use your vehicle harness. This has nothing to do with LS swap
Fuel - Use fuel level lead from your fuel pump hangar. I used the g body harness

 

[Moochie]

so the info you just gave me is associated with the ls swap ? correct. im going to be running 4l60 transmission

 

[vader87]

What harness and PCM are your using? I am asking so I can send you the pins that need to be used. Here are some dash pinouts you will need.

fuel gauge- pink wire in the dash. As stated above nothing to do with the swap.
volts-brown wire from the dash. Just shows voltage gong through he system nothing to do with swap
oil pressure- all aftermarket and a separate wire that has to be ran
oil pressure

tach- PIN 10 white wire
tach_circuit_fix

water temp-all aftermarket and a separate wire that has to be ran. You can use the head or tap into the system somewhere.
water temp

dash

Speedo-
As soon as you tell me the pcm and harness, I can tell you the pins

 

[454GrandPrix]

volts-brown wire from the dash. Just shows voltage gong through he system nothing to do with swap

Question about this brown wire: is it a dedicated wire meant for the voltage gauge only and no other purpose? Will it show accurate voltage reading (ie, equal to what would be measured directly at the battery)?

My GP came with a full compliment of idiot lights. I installed a set of AutoMeter gauges, including a voltage gauge. To power this gauge, I just connected its input to the same 12v power wire that runs the other three secondary gauges (fuel, oil pressure, water temp). My voltage gauge always reads low--for example, it will display right at 14.0v when the battery sees 14.5-14.6 volts immediately after startup. Furthermore, its reading drops even lower when there is a significant load placed on the system--with my headlights and radiator fan both on, the gauge needle will drop to 12.5-13.0v even though the battery sees 14.0 volts. (I know what my actual battery voltage is at all times thanks to my TCI EZ-TCU controller, which is wired directly to the battery terminals and has its own voltage readout function.)

Is this because I didn't use the correct wire for my voltage gauge? Or will that not matter?

 

[Moochie]

What harness and PCM are your using? I am asking so I can send you the pins that need to be used. Here are some dash pinouts you will need.

fuel gauge- pink wire in the dash. As stated above nothing to do with the swap.
volts-brown wire from the dash. Just shows voltage gong through he system nothing to do with swap
oil pressure- all aftermarket and a separate wire that has to be ran
oil pressure

tach- PIN 10 white wire
tach_circuit_fix

water temp-all aftermarket and a separate wire that has to be ran. You can use the head or tap into the system somewhere.
water temp

dash

Speedo-
As soon as you tell me the pcm and harness, I can tell you the pins

i plan on using a harness and pcm that im going to order from a company that is already made to be an stand alone harness and the pcm is already going to be reflashed

 

[vader87]

Question about this brown wire: is it a dedicated wire meant for the voltage gauge only and no other purpose? Will it show accurate voltage reading (ie, equal to what would be measured directly at the battery)?

My GP came with a full compliment of idiot lights. I installed a set of AutoMeter gauges, including a voltage gauge. To power this gauge, I just connected its input to the same 12v power wire that runs the other three secondary gauges (fuel, oil pressure, water temp). My voltage gauge always reads low--for example, it will display right at 14.0v when the battery sees 14.5-14.6 volts immediately after startup. Furthermore, its reading drops even lower when there is a significant load placed on the system--with my headlights and radiator fan both on, the gauge needle will drop to 12.5-13.0v even though the battery sees 14.0 volts. (I know what my actual battery voltage is at all times thanks to my TCI EZ-TCU controller, which is wired directly to the battery terminals and has its own voltage readout function.)

Is this because I didn't use the correct wire for my voltage gauge? Or will that not matter?

Either will work, Remember you are going through fuses and a ton of older wire so I am sure there is a little drop in voltage.

 

[vader87]

i plan on using a harness and pcm that im going to order from a company that is already made to be an stand alone harness and the pcm is already going to be reflashed

I understand but there are different pcms and harnesses. A 1999 LS1 harness and pcm are different from a 2003 LM7 Truck harness which is different from a Corvette PCM and harness.

 

[454GrandPrix]

Either will work, Remember you are going through fuses and a ton of older wire so I am sure there is a little drop in voltage.

Okay, this is what I have been telling myself all along. I hadn't really worried about it until this post. I'm sure I could run extra wires through the firewall and to the battery to get a more accurate reading on that gauge... but as is, it tells me what I need to know so I doubt I'll bother.

 

[79VS86]

gauge pin out? On79 Monte Carlo?? Done a 5.3 4l60e combo fuel injection red and blue pcm. Seeing if any one has the pin out from the original pigtail im currently upgrading gauges just wanted to used as many factory leads as possible.