hello all... been a while - trying to get over this pain or glory moment, and would like to know if someone has accomplished this task or taken it on and found it to be more or less fruitless in efforts. I am a neurotic when it comes to having things in a vehicle that have no operational function. Either use it or lose it! but, I am a victim of my own problem, cause I would like to have the coolant temp gauge on dash to work ( I digress oil press. gauge) for a secondary temp. I have a autometer already, but would like to use that dash one if I could. I have a location in my rad. inlet neck that could fit the sensor, but do not know what wire to find to connect it up. .. Who could guide me somewhere - the harness has been butchered a bit, but nothing extreme - so proper location of wire(s) and colors are a need, please. thanks

 

is there a particular series your car is?..or is a secret?

 

You will need the correct series sensor for the correct series gauge cluster (S4 for S4, ect.).
The S4 sensors are almost all M10x1.0 straight thread with a bullet-style single pin connector.
I say almost all are M10 because some late ‘88s came with a 1/8” BSPT fitting that has the correct calibration for an S4 cluster.
The S5 sensors are all 1/8” BSPT (BRITISH, not NPT) and use a ¼” spade single pin connector.

You can buy whatever sensor you need for your dash here and add it to your engine:
https://www.mazdatrix.com/86-92Electrical-Engine.htm

For oil temp, All engines 81-91 use the same pressure sensor.
It is also 1/8” BSPT and is available here: https://www.mazdatrix.com/86-92Electrical-Engine.htm

For wiring, the easier is to just splice into the gauge cluster wiring.
There is a short harness that connects the dash wiring to the actual gauge cluster behind the steering wheel.
In that harness you’ll find a yellow/white wire. This is the coolant wire.
You’ll also find a yellow/red wire that is the oil pressure sensor.
If you clip those wires and run fresh wire from the gauge cluster to the sensors, you should have working gauges!
Also, the tach input is a yellow/blue wire, if you can use that.

If you see page 40 of the 1988 FSM Wiring Diagram, there is more details on the cluster wiring.

 

Apologies for delayed response, s4 - I have an engine swap and is reason current metering is done standalone. The drivetrain is sbc, and tach is already calibrated. The speedometer cable I am going to see if custom fab to mate the two. I haven't updated my account in while due to app issues, so I'm on and off randomly- thanks again for help

 

I had located the wires, thanks. The oil pressure sender wire connector just happened to still be intact, and just tucked behind other wires near firewall on driver's side. There was no locating the original engine bay wire for coolant gauge, so I was able to locate the wire from dash cluster and speared it from plug, with plans to connect it independently. Thanks again- now i have to try test cluster gauges to ensure they are working

 

I'm at a crossroads to use the stock stuff as I got gauges that I installed and they look all nice and fabulous..haha!

I may re-do the dash a bit,seeing the weather went to **** here I think I got some time to re-evaluate things.
My speedo may be a GPS unit that I got.

 

I've heard and read about the stock gauges not being as accurate, and since the sweeps only really show you good, avg, & too late - I think that leaving them unhooked is just added weight. Surprisingly, I bought a single din gauge plate for dash that fits and looks great!



$12 eBay dash gauge panel