Instrument Cluster Wiring (79 GS750)

[Guest]

For those changing out the huge instrument cluster (tach, speedo, indicator lamps, etc), for an aftermarket, here is the wiring info to save you mapping out the wires.
The bike I am working on is not an OEM restore project. Its my daily rider which I am working on doing a proper cafe racer (not an ebay racer). With that, I'm keeping most original parts where I can, aftermarket where it makes sense (cost and functionality).

OK, the wiring referencing the plugs from the cluster as the wire color codes may not be the same on every bike;

Gear selector cable, plug with indent at top, left to right, top down:
Neutral -----> Loose wire butt connector
Empty 1st Gear
5th Gear 2nd Gear
4th Gear 3rd Gear

Indicator cable, plug with indent at top, left to right, top down:
Hi Beam -----> Loose wire butt connector
Backlight Ground
+12V Oil Light
Right Turn Left Turn

My almost completed wiring harness. Need to pull off the red tape and use proper black. Harness makes the all in one gauge plug and play thanks to a spare cluster I had in the bin.

 

[Guest]

This is why I went through all the troubles of mapping the wires.


This is it's replacement (bench test before wiring harness build). Weight drop of 1259g (2.8lb) and a whole lot less bulk up front.

 

[Guest]

Thanks for posting this up all. I'm planning on changing out the stock one on an upcoming project as well, great info. Where did you wind up buying the replacement gauge?

 

[Guest]

Thanks for posting this up all. I'm planning on changing out the stock one on an upcoming project as well, great info. Where did you wind up buying the replacement gauge?

I ended up buying this one from ebay. Its available through a number of shops, but ebay was the cheapest.
I will however admit, documentation on this one was a pain to find. The large plug used in the unit is a 20 pin male plug found on computer ATX power supplies. I looked to find a new plug to build my harness, but couldn't easily find one and gave in to recycling one from a dead computer power supply.

I should note, this one does not have an oil light and does have a fuel gauge. Not sure what I will do about the oil light. Might mess around while its all off the bike and see if I use the fuel gauge for the oil light or add a small LED or just go without.

If you go with the same unit I have here (goes by 'DSP SYS' or another brand), the following wiring diagram will help you confirm the wires (ignore the colors as they don't or didn't match mine).