Long story short my most of my gauge cluster doesn't work.

What works: air bag light, speedo
What doesn't work: fuel gauge, coolant, tach, everything else

It was working before I took the dash out to do a cage. I deleted the blower motor while the dash was out so I did not plug that back in. I also deleted the clock spring while it was out, removed/reinstalled the ecu and painted the floor. Everything on the driverside has been plugged in. There were 2 ground wires that were just terminated to the edge of dash metal on each side. I had to trim that for the cage so I just drilled and mounted them up a little higher. I checked resistance from the dash metal where the grounds were to the a bolt into the firewall and it was good. The only things I could find while searching for similar issues was some guy didn't plug something in on the passenger side of the dash. I looked and the only thing I could see over there was blower motor wiring which I don't have anymore. Any Ideas?

 

The year of miata generally helps.


it really does sound like a ground issue, Check from the Tach ground screw to a good ground.

 

I guess that would help lol.

It's a 1993. Ill check the ground screw again. I did have to cut that tab off, recrimp and move up the ground. Some paint probably got in the threads for the dash mounting holes so that could hurt the ground as well.

 

Make sure you didn't mess up one of the copper traces on the back of the cluster. I did that on mine and everything except a couple lights stopped working.

Also, there's a big connector on the passenger side that works a lot of different things. Should be right by where the dash support meets the body of the car

 

Ever get this figured out? I also have a speedo that works on my cluster but not the tach. I'm running a MS and thought it was that but all the common fixes don't seem to do anything. Think it's maybe the cluster itself or a wiring issue similar to yours.

Is there a certain way to test the cluster itself for the input on the tach portion? I'm not particularly great with tracing electrical issues.

 

I'm the idiot who forgot to plug in the connector on the passenger side. I was SURE it was an old HVAC/Blower connections. It was not. Not saying you did the same thing but it might be worth just double checking. I slapped myself in the face when I realized there was a perfectly shaped receptacle plug to accompany my unused "hvac" connector.

 

Sorry for forgetting to follow up on this. I was an idiot and did the exact same thing as rigidbigelsworth.... I assumed it was just useless hvac connection on the passenger side of the dash lol.

 

Yeah, wonky things happen when you forget those plugs.