With that new radiator I got, I didn't bother having a bung put in for the coolent level sensor. I looked in the FSM and it shows the sensor grounding through the coolent. My question is this: If I ground the sensor wire to the chassis, will this prevent the light and such from going off. BTW, I don't have my battery and stuff in the car right now...plus it's all pulled apart to paint from the strut towers foward.

 

All it needs is to be grounded. I would rather have it put in than bypass it. I might for get to put the cap back on and kill her. I would rather have some warning than no warning.

 

That annoying sound has saved me. Figure a way to get it installed or face the idea of having to kick your own *** when you melt the engine for lack of water...
My $.02

 

But all that goes away when I put the stand alone in. Plus it's not a daily driver, so I'm quite careful on the fluid levels and watching the gauges.

 

I have repaired a couple of ECUs now that people have grounded the sensor wire to stop having the buzzer and burnt up a resistor inside the ECU. I would not recommend just grounding the sensor wire.

 

Thats what i did with my sensor wire. I just ground it to the chassis. that was nearly 2 years ago. and i am a fluid checking freak (everytime i stop for gas)

How will grounding that hurt my ECU. please someone tell me. cause i'll change it right away... lol

 

I have seen burnt resistors on two now, and in both cases the owner had just grounded the wire.

In one case it appears to eventually had the problem spread to the bac control from over heating inside the ECU. They are 1 watt resistors after all.

I imagine that a extra resistor on the sensor lead is all that is needed to ground the wire and not burn up the ECU, but I can't confirm that.

 

so i could be burning up my BAC.... or even my ECU as we speak right now?

 

and how can i stop this from happening?

 

I don't know for sure yet... I have to dig a little more into the ECUs. All I can say for sure is that the resistors are burnt up and there is heat damage to the PCB on both of the ECUs that have had the sensor grounded.

I'll try and check more tonight.

 

yeah, I was going to check the resistance of coolent with my DVM and try to mimic that with the chassis ground. Wouldn't see why won't work. Again, this all just a band-aid till I get the stand alone installed.

 

I don't get it. The coolant level warning system is not connected to the ECU at all, it's in the gauge cluster. How could the ECU be affected by grounding the coolant level sensor wire?

 

Ahh your right, I just checked the board on the one I am fixing. It was the temp sender for the water. Pin 2I

Good call. I take back all my earlier posts in this thread, but still think its intresting the over heated sensor input on both cars with the disconnected rad fluid level sensors.

 

As I thought, the ECU has nothing to do with the coolant level warning, so an aftermarket ECU won't make any difference.
My advice would be to get a boss welded onto the radiator so you can remount the sensor. Most of the aftermarket FC radiators seem to have this. Given how damaging an overheat can be to a rotary, a bit of cheap insurance like this is absolutely worth it. Mazda obviously thought so...

 

good thing I have that nice big autometer temp gauge to look at Perhaps I'll integrate it into the overflow, but I'm not going to put it in that nice radiator.