Need wiring help with Cluster swap.

[87Bob]

I am swapping out a cluster with gages to one with gages and a Tach. The year of the Tach cluster is unknown it is going into an 85. I have checked the wiring one to the other and the circuit boards are the same except for the gas gage position and the tach (which I expect). The pig tail in the 85 has one open wire position #14. The Pig tail from the Tach gage set up is missing two wires in positions #14 & #15. Number 14 is the 3rd lug of the oil pressure gage (which is un-needed). Number 15 is the common between oil pressure, water temp, and fuel I am assuming it is their ground? Also I was given the pig tail for the tach it has a 3 prong connector that goes on the back of the tach that contains a black wire(ground) a brown wire (to the distributor) and a pink (12V hot) that I am assuming. However connected to the pink wire is another harness that I don't have a clue where it goes to or what it is for. It is about 32 inches long and has two connectors on it. One has 5 wires in it and the plug is in the shape of a bow tie. The other end has 4 wires in it and it is in the shape of a "T". Two wires side by side on the top like this --two vertically like this II. In each plug the wire colors are tan with a white strip, tan, light blue, light green. The bow tie shaped end has the additional pink.

These are my questions:

1) Does anyone have a wiring diagram specific to an 85 Cluster with Tach and gages that scan me a efile copy?

2) Does anyone have an 85 Truck apart that has a factory Tach that can shoot me some pictures?

3) Does anyone know if the output for the little fuel gauge is the same as the big one?

4) Can I just move the wire in the loom to the new position for the gas gage or do I even need to?

5) Can anyone shed some light on these questions?

I don't want the nickname Sparky.

Thanks in advance for any help you can give.

[PhilaTruck]

Originally Posted by 87Bob

The year of the Tach cluster is unknown it is going into an 85.

I don't want the nickname Sparky.

Thanks in advance for any help you can give.

It sounds like you already know this, but putting the wrong years together can definitely cause a fire. I woouldn't spend the time with a cluster of unknown year.

I think a coupla years ago Crossy wrote a long detailed description of what works with what. Try searching his posts.

He might be able to help answer some of your questions, too.

[BLE 'BURBAN]

Originally Posted by 87Bob

I am swapping out a cluster with gages to one with gages and a Tach. The year of the Tach cluster is unknown Does this cluster have an amp gauge or a voltage gauge? mechanical or electric oil pressure guage? it is going into an 85. I have checked the wiring one to the other and the circuit boards are the same except for the gas gage position and the tach (which I expect). The pig tail in the 85 has one open wire position #14. The Pig tail from the Tach gage set up is missing two wires in positions #14 & #15. Number 14 is the 3rd lug of the oil pressure gage (which is un-needed). Number 15 is the common between oil pressure, water temp, and fuel I am assuming it is their ground? You can look for a "+" or a "-" on the printed circuit to tell you if it's the common ground or the common main power lead Also I was given the pig tail for the tach it has a 3 prong connector that goes on the back of the tach that contains a black wire(ground) a brown wire (to the distributor) and a pink (12V hot) that I am assuming. However connected to the pink wire is another harness that I don't have a clue where it goes to or what it is for. It is about 32 inches long and has two connectors on it. One has 5 wires in it and the plug is in the shape of a bow tie. The other end has 4 wires in it and it is in the shape of a "T". Two wires side by side on the top like this --two vertically like this II. In each plug the wire colors are tan with a white strip, tan, light blue, light green. The bow tie shaped end has the additional pink. This extra wiring leads me to believe this cluster MAY have come out of a vehicle with a diesel engine in it. If this is the case I don't think the tach will work properly on a gas engine. I may be wrong on that so it would be best to pm a message to Crossy for verification on this.

These are my questions:

1) Does anyone have a wiring diagram specific to an 85 Cluster with Tach and gages that scan me a efile copy?

2) Does anyone have an 85 Truck apart that has a factory Tach that can shoot me some pictures? I believe G.M. stopped putting tachs into the trucks in either '82 or '83

3) Does anyone know if the output for the little fuel gauge is the same as the big one? No it's on the opposite side

4) Can I just move the wire in the loom to the new position for the gas gage or do I even need to? Yes you will need to as the sender circuit is on the opposite side of the plug from your original cluster

5) Can anyone shed some light on these questions?

I don't want the nickname Sparky.

Thanks in advance for any help you can give.

Also check the gauges for temp and pressure ratings. If they are the same you can still use your original sending units otherwise you'll need to swap them out for the proper ones as well.

[80SPORT]

Last year for factory tach was 1981
Tach was not avail w diesel pu
Tach is powered up on own circuit;pink is ign +;brn to tach term on dist via a capacitor;black is ground.
If your tach dash has voltmeter and electic oil gage you can use a 1981 wiring diagram;if you have mech oil gage and ampmeter your dash is pre 77 and will not work.(i assume your truck has voltmeter/oil gage from factory....if you have only warning lites you will require a complete harness)

[87Bob]

First, thank you responders for your help now let me see if I can answer your questions. In doing a wire trace this is what I came up with:
As viewed from behind


Orginal cluster
Left Right
10 Fuel Gauge High Beam 1
11 Brake Warn Light Cluster Lights 2
12 Common for #2,#4 Volt Meter 3
13 Choke Warn Light Volt Meter 4
14 4 WD Warn Light Oil Pressure 5
15 Seat Belt Warn Lt Gauge Common 6
16 Rt Turn Signal Not used 7
17 Left Turn Signal Not used 8
18 Ground for #8,#7 Water Temp 9
Cluster Lights


Tach Cluster
Left Right
10 Not used High Beam 1
11 Brake Warn Light Cluster Lights 2
12 Common for #2, #4 Volt Meter 3
13 Choke Warn Light Volt Meter 4
14 4 WD Warn Light Oil Pressure 5
15 Seat Belt Warn Lt Gauge Common 6
16 Rt Turn Signal Fuel Gauge 7
17 Left Turn Signal Fuel Gauge 8
18 Ground for #8,#7 Water Temp 9
Cluster Lights

Phillatruck:
If I knew what year the Tach cluster was supposed to come from it would only answer half of the story. I believe that I traced down each wire on the circuit board and I know where they go except for the additional wires in the additional harness. I have an 82 shop manual which still shows a schematic for a tach equipped cluster. However the color codes are different then what is on the 85 truck and on the pigtail stub that I got with the gages. I did have the cluster checked by a guy the does custom gage repair he said all of them checked out as good. Also thanks for the tip on Crossy I’ll do a search.

BLE Burban:
*)Both Clusters have Volt gages and Elec. Oil pressure gages.
*) I looked for +- markings and found none on either cluster.
2) Does anyone have an 85 Truck apart that has a factory Tach that can shoot me some pictures? I believe G.M. stopped putting tachs into the trucks in either '82 or '83 Thanks for the info!4) Can I just move the wire in the loom to the new position for the gas gage or do I even need to? Yes you will need to as the sender circuit is on the opposite side of the plug from your original cluster Ok I’ll move the wire in the plug for the gas gage!80Sport:
Thanks for your input as well It would appear that I am closing in on getting this all figured out. Thanks for your help guys! Sorry the charts run together but when I edit them it looks right on the screen till I run preview then it bunches them together.

[87Bob]

I double checked everything and tried it the Volt, Oil, Water and Fuel gages work great. I have to run the Tach wires before I do a perm install thanks for your help. 87Bob

[PhilaTruck]

Nice work, Bob!

[PhilaTruck]

So, I know this issue's done, but I mentioned Crossy's info on gauges and since Dave was kind enough to point it out, I wanted to post it.

It's here at Jeff's site, 73-87.com.

-Todd

[87Bob]

Originally Posted by PhilaTruck

So, I know this issue's done, but I mentioned Crossy's info on gauges and since Dave was kind enough to point it out, I wanted to post it.

It's here at Jeff's site, 73-87.com.

-Todd

Good Info!

[heavychevy79]

Bump

[Captkaos]

Why are you bumping all the cluster posts?

[tvblazer78]

I think I am going to bump my Autometer dash build..

[heavychevy79]

Originally Posted by Captkaos

Why are you bumping all the cluster posts?

What's his name was looking for the info, and I had time to look for it.

[RonnieTheBull]

[QUOTE=87Bob;3059547]First, thank you responders for your help now let me see if I can answer your questions. In doing a wire trace this is what I came up with:
As viewed from behind


Orginal cluster
Left Right
10 Fuel Gauge High Beam 1
11 Brake Warn Light Cluster Lights 2
12 Common for #2,#4 Volt Meter 3
13 Choke Warn Light Volt Meter 4
14 4 WD Warn Light Oil Pressure 5
15 Seat Belt Warn Lt Gauge Common 6
16 Rt Turn Signal Not used 7
17 Left Turn Signal Not used 8
18 Ground for #8,#7 Water Temp 9
Cluster Lights


Tach Cluster
Left Right
10 Not used High Beam 1
11 Brake Warn Light Cluster Lights 2
12 Common for #2, #4 Volt Meter 3
13 Choke Warn Light Volt Meter 4
14 4 WD Warn Light Oil Pressure 5
15 Seat Belt Warn Lt Gauge Common 6
16 Rt Turn Signal Fuel Gauge 7
17 Left Turn Signal Fuel Gauge 8
18 Ground for #8,#7 Water Temp 9
Cluster Lights



This is a great break down of the plug re-pin....think I'm gonna try and tackle this during the week before Carlisle this weekend