Hey guys I have a 1983 Mazda rx7 with the 12a rotary. How far up should the needle go on the gauge for the coolant temp? I changed the sensor thinking that maybe it wasn’t reading correctly but is it suppose to be about right here? It starts at the bottom and only climbs up to this post and never goes any further?

 

Thats perfect! Less than 1/3 is the ideal and 1/4 is perfect. Send it!

 

welcome to the board.

from what i remember of my old '83, and my brother's car (when it was stock), that's about where the needle sat.

 

I have a 1983 GSL (just purchased 2 weeks ago) and my needle looks exactly as yours. I too was going to buy a new temp. sensor but my uncle said not to mess with it unless it wasn't working. I need to change the water pump and was going to add the sensor to my laundry list but realized it wasn't necessary per my uncle. Now that I see your picture; I am more confident that the temp gauge is working properly. My gas gauge isn't working on mine though. It only goes to a 1/4 tank when I fill up so I need to research how to fix this eventually. For now I have ran the car for 200 miles before I go in for a fill up. I've been using Lucas 2 stroke at every fill up that I have on hand from my Rx8.

 

My temperature gauge doesn’t even work. Changed the water temperature sensor and checked the condition of the wire that naps on the end of it. This didn’t make any difference. What should I check next?

 

My 83 never goes past that.

 

Only other possibilities are the wires to the cluster or the cluster gauges. The connections on the printed circuit board to the gauges can become corroded. Remove the cluster and clean the nut connections and screws for the gauges and wires one at a time and check the two plugs and solder connections on the plug pins are not cracked. This is a '79 cluster but the '83 will be similar in construction.


1979 instrument cluster.

 

I will check this as soon as I get a chance to pull the gauge cluster out.