So last fall I finally got my 93 Touring back with a fresh, new (Mazda rebuilt) engine. The only problem is that the coolant level sensor light and buzzer simply will not go out. My mechanic has spent several hours trying to hunt down the problem to no avail, now he is wanting to replace the cuircuit board on the insturment cluster. I am not completely convinced that is where the problem is and I am getting tired of spending money for the experimenting.

Has anyone ever heard of this problem before? Does a replacement of the insturment cluster circuit board sound reasonable? Please help.

My car is a 93 touring daily driver. All stock, with about 102k mi on the car and about 2k mi on the new engine. Yes, the sensor has been replaced with a new sensor.

Any help or advice is greatly appreciated!

Thanks!
BRAD

 

either change the sensor, and if that is not it. go recheck your work. there are 5 (if my memory serves me right) conection in that line. if one is not connected, it will cauze the buzzer.

 

Thanks for the reply. Actually, the sensor has been replaced. I have checked the X-12 and X-06 connectors and can't find any problems. I just realized that I neglected to mention in my earlier post that My mechanic at one point misread the schematic and connected the sensor directly to the R4 on the circuit board in an attempt to eliminate the connectors as a problem. He tells me that the light and buzzer did stop at one point and then he couldn't do it again. The last time he tried to hook it up, the oil pressure gage and light don't work at all. I hope I'm being clear enough. Thanks for your help!

BRAD

 

there is a big wire harness over by the sparkplugs that has a handful of connections being made there. One of them is a small black plug that just barely pokes out of the harness. On mine anyway it just barely pokes out and its on the back side of the harness pretty far down so you'd prob never notice it (from the top anyway)

If that connection isnt made your light will never go off, I had the same problem and it just wasnt hooked up right.

Anyway, I felt like maybe he has it pluged in the wrong connector or something since there are a handfull of similar plugs all around the same area.

Hope it helps, if not then sorry,
STEPHEN

 

my bet is what spo's said..the wire just jumps across from the sensor to the harness.and isnt a very nu=ice connection inho...
first check the sensor when its wet it will be 12- so basicaly when its wet if you hook a multimeeter to 12+ and the neg to the sensor it will read batt voltage...


if sensor checks out ok then hook a 12- to the terminal in the harness the little black one by the ps pump but under the elbow...
is that dosent shut it off..its somthing further in the car


hope that helps
len

 

ohh btw..to the best of my knowledge theres only 1 level sensor and 3 or 4 temp sensors....

the level sensor is the black one on the fron of the thermoneck ..right above the rad hose

 

Mine did the same thing until it got properly burped. Didn't have anything to do with the sensor or the level. I would get the level filled up and the sensor would go off....cap goes on, and a few minutes later the sensor would go off again. The level was right up where it supposed to be and the light would go off and on. So, I checked the sensor...it's ok, checked all the wires, they're ok...still the light is driving me nuts.....but I would always hear a lot of water whooshing on the passenger side when first starting up the car. So I did a thorough burp and voila!, solved the problem.

If your light doesn't go out with the water level above sensor heighth then burping's not going to help.

 

Is this a valid test? I took the plug off that runs to the sensor, I then ran a wire from the side that goes to the car to the neg on the battery. Is this correct?

The light still came on, if I'm doing the test right, what should I check?

Thanks!

 

This is the exact problem I have run into. So far we are into the insturment panel with still no luck. I did notice in the manual schematics that the exhaust overheat will also cause that light to come on. However, it is internally wired such that the oil light should come on as well. I will let you know if we find anything else. I just want my car back!

BRAD

 

mine did the same damn thing. haven't fixed it yet (only about a week) after putting in a fresh mazda rebuild. I could dunk the sensor in a bucket of antifreeze and it still wouldn't do anything. new sensor, checked all te wires, etc....

I could accept the light, but no buzzer. That's just aggravating. Mazda was pretty good at hiding that buzzer, so I got cocky. I tore my whole dash apart looking for it, unplugging and checking everything. The service manual seems to have "forgotten" to add this part in the book. how convenient. Anyway. There's a little black box on the left kickpanel (driver's) near the fuse box. First, unplug and unbolt the silver/grey box that holds it on. Then, unscrew the black box (long like a rectangle. It has three plugins. Unscrew the back off the box and remove the circuit board. You will see a funny little round black box on the board with a hole in it. If you look in the hole you will see a metal piece. CAREFULLY. Melt the soder on the back of the LARGER TWO HOLES (not the tiny third one) while pulling it the speaker. Voila! reassemble. No more buzzer, and no more aggravating door beeps, ignition beeps, etc. SILENCE!!

The light still comes on, but who cares. At least I can drive it with no buzzer.....

BBBBBBBBBBBBEEEEEEEEEEEEEEEEEPPPPPPPPPPPPPPPPPPPPP PPPPPPPPPP!

that sucks.


hope i helped....

 

Well, the circuitry looks to be the problem. I put a tester on the senser out wire and the battery positive, and I get a somewhat dim light, so it appears its sending a ground signal. (though its not super strong, but maybe thats because its grounding in water?)

 

Thanks for the info, are you referring to the p/s fill tube?

 

whats the proper way to burp your collant system????

 

How I did it was pull both rad caps off, then take off the 5/8s hose off the back of the intake manifold, use a funnel and fill it through there until the filler tank was to the top.