well, This is just pissing me off..... My "add coolant" light came on - along with that pleasant loud buzzing sound that makes me want to drive my car into the leading car ahead.

I have since replaced all fuses, and all relays- I have done a complete coolant flush, and a have topped it off.

The light/sound still comes on right away..

What do I do- what is there to do, it will occaisionally stop- then come back again. is there a sensor that would cause this that may be loose- if so, where is it at, I can't find one.

At the very least- is there a way to turn off the annoying buzzing sound?

Thank you,
jc

 

My car did the same thing when I first got it except that it wouldn't really turn off (hence me naming the car Lloyd, since it made "the most annoying sound in the world).
I just ended up disconnecting the sensor altogether since there's no way to leave the light in tact and turn off the buzzer. You just have to keep an eye on your coolant levels.

 

bleed the system properly.

 

Couldn't the coolant level sensor be bad? Mine does the same thing but just for a split second...

 

Sometimes the sensor can be replaced and it will solve the problem. Othertimes it's a more in depth wiring issue and replacing the sensor will only cost you extra money without changing anything. That's why I just disconnected mine, it's not rocket science keeping the coolant level up anyway.

 

Rocket Science? No. But it's there for a reason. As a precautionary item. It's not like that piece is really that expensive anyway, and if it is the wire *Which mine will be soon*, just get the gauge wire, and replace it. Nothing hard, nor expensive. If something breaks on the car, and you just disconnect it/take it off...you'd run out of car fast! lol

 

They call them dummy lights for a reason
Whoever had the car before me seriously screwed with the wiring, and no amount of playing with it fixed that stupid sensor. I was not about to change the wiring in the whole car just to find out why my coolant sensor was squealing so it got cut.
The car has been my daily driver for going on 5 years now (almost 100 000 kms on the rebuilt engine) and still runs like a top. I wouldn't call that running out of car fast, would you?

 

No offence, but that's the craziest thing I've every heard. Cluelessly replacing random parts is the worst kind of troubleshooting. In most cases, including this one, it's a complete waste of time and money. There are no relays in the system and if any fuses were blown then obviously the system wouldn't work at all. Why would you replace perfectly good fuses anyway?

If you are sure that the radiator is completely full, then there must be a problem with the warning system. Grab your FSM, read the appropriate section and found out what's wrong. If you don't have the FSM, click here and download it in PDF format for free.

There is a radiator level sensor. Guess where it is...

Yes, by finding the problem and fixing it. Don't listen to silly people who tell you how to disable the warning system. It's there for a good reason and could save you from an expensive rebuild.

BS. Troubleshooting properly costs you nothing. There are very rarely any issues with any part of the system other than the level sensor, so you shouldn't give bad advice based your experience.

It's not rocket science to properly fix your car either. The warning isn't just there for people who forget to check their fluid levels. Keeping your coolant level up won't help you one bit if a hose splits when you're driving. If you loose coolant, the warning will go off well before the engine temp starts to rise. Surely you can see the huge advantage in that.

Only dummies call then dummy lights.

So if you knew there may be a problem with the wiring, why did you keep playing with the sensor?

Dude, it's one wire... This is a perfect example of how not to attempt to repair a problem. I hope others with this problem can clearly see that.

Wouldn't it be funny if something happened tomorrow... I hope that's not your attitude to other forms of insurance. My low-coolant warning's never gone off in 6+ years of daily driving, but I'm not dumb enough to think that means it's of no benefit to me.

 

Pretty damm stupid.

It is a single wire that ground through the coolant, and will warn you if you suddenly loose coolant (such as if a hose bursts underhood).

Checking your coolant level means nothing if you pop a hose and all your coolant drains onto the ground... your water temp sensor doesn't work if there is no water.

FIX the car, Don't bust it further. Disconnecting something that is there as a safety device against loosing your motor is just stupid.

And if you can't figure out what is wrong with a single wire that ground through the coolant, you probably should even be working on the car... well alone owning one.

I mean, you put a meter on the sensor at the radiator, and it either has ground on it, or it doesn't. If it doesn't then either your coolant is more than an inch low in the radiator or you have a bad $20 sensor. Pretty idiot proof, and simple.

Only someone that doesn't care about his motor disconnects that sensor.

 

If you guys would like to come check out the wiring issues with my car, then be my guest. I tried fixing it to no avail since the wiring in general is messed. Took it to a mechanic (who specializes in 7s, mind you) that also couldn't fix it.
I was not the one who disconnected it personally, he did it.
And like I said, this was on the DD. I bought it for $150 bucks and goofed with it over a winter, it's not the nicer of the two 7s. It's winter driven, the body is ****, but it gets me from A to B.
Don't go telling me I shouldn't own a car just because I have one little beater that gets the bare minimum. As if I could afford to keep TWO RX7s up

 

dude or dudette, if you can't fix a $20 sensor, then yes, you shouldn't own the car.

and I wouldn't take my car to a mechanic that can't figure out how to troubleshoot a single wire sensor, because he must be clueless.

The coolant sensor circuit, is so simple a monkey can figure it out. It is a simple brown wire, that grounds through the coolant, and goes from the top of the radiator to the gauge cluster. One wire. No resistor, no electronics, not even some fancy computer. One wire that either has ground on it from the coolant or does not. You can't get any simpler to trouble shoot.

Most of the time when people claim the wiring is messed up, it is because they don't know what they are doing, and have fucked something up.


Most electrical gremlins sit behind the steering wheel when the car is driving down the road.

 

Actually it's not quite that simple. There is a controller built into the instrument cluster, but it's failure rate is very low and it still only has one wire like you said. The FSM has very simple instructions for testing the system, but I bet they weren't even looked at...

 

Ok, some further updates on the issue- I now is almost constantly on- I dont understand what you guys mean by "bleed the coolant"

I have completely drained, and have had a professional coolant flush, completely topped off, and the light still retains.

I also realized that it comes on when the car is on accessory, not even running...

I disconnected the connector from the temp sensor on the top of the radiator, and then let it idle- it immediately came on. It is one wire, yes- and I cant figure out why this one wire is causing this- this is why I ask for possible advice from another rx7 owner, there is no need for the hate going on.

I only replaced fuses/ relays that I had found at that moment to be bad ( I just got this car, and am trying to fix everything going on)

Thanks you guys,
JC

 

When the engine is cold and you open the radiator cap on the top of the radiator (not the filler neck) is there coolant all the way too the top?

Again when cold, if you squeeze the top radiator hose, do you hear air bubbles.

If no to the first one, then they didn't fill the radiator.

If yes to the 2nd, then they didn't fill the radiator.

 

It is full, and there are no bubbles- I know how to flush a coolant system, but I even had it done at specMazda ( a shop local to me). It was done properly, But how would the light come on off of accessory, when coolant isnt even circulating through the system.

 

Hehe.. man...

"Add coolant light came on... so I changed the fuses..."

Serious?

 

Not bleed the coolant, bleed the air from the cooling system. The best way to do this is run idle the car from cold up to operating temp with the filler cap off so the air can get out as it moves around the system.

So it sounds more like a problem with the warning system. Read the relevant section in the FSM Body Electrical System chapter and do what it says.

 

I blew the heater hose, and the coolant leaked out. It was almost empty, Its just as well I had the buzzer cos i wouldnt have known. I had to take the thermostat out and replace it cos it sealed shut. I havent had a problem since. I should probably replace the hoses though, its been a hot summer here.

 

Wow, some people really dont read before they make a post- I had done everything regarding "coolant" level. Then I thought maybe there was a wiring issue- this is why I went throught the electrical system. Yes, I bled the air out of the cooalant system. It is still full, and I am not going to remove the sensor.

 

remove the sensor, and check to see if there is continuity between both sides (wire side and probe side) or unplug the sensor but leave it in the radiator and check to see if there is ground on the sensor wire.

And exiletalon, just because a professional shop replaces the coolant doesn't mean they did it correctly. I have seen Mazda dealers with Mazda trained mechanics/techs that were unable to figure out there was a bad switch for reverse, and wanted to change the battery instead.

Unless you have checked it yourself, it means nothing.

 

I know people loose their cool when they feel strongly about something...but ultimately we are trying to save some of you future trouble. Also, some of you really don't get the point. Without mentioning names, some guys here have proven themselves over and over. On to more info...

The coolant level buzzer/light goes on in accessory, because it doesn't need the engine running to know that coolant is low. Engine running or not, it should be full (coolant level). We're not saying anyone or their mechanics are morons, but many times the bleed plug is overlooked. It is near the top passenger side of the rad, near the radiator water neck. After filling up the coolant, you want to warm up the car with the rad cap off, engine on. As coolant circulates (make sure the heater is on hot) because of the water pump, air bubbles escape. Some may be still trapped because of the shape of the water inlet at the rad, so you have to loosen the bleed plug until a good stream of coolant comes out. Then you retighten the bleed plug, fill the coolant and close the cap. One important note is that if you replace the thermostat, fill as much coolant on the water pump side as you can before putting the replacement back in. The thermostat needs coolant near it for it to open in the first place, or you may have air in there. I'm getting off topic though...

Testing the sensor (or coolant level): To test whether the sensor is the culprit (or the coolant level), unplug it, and ground the wire that you unplugged (on the harness side, obviously). If the buzzer/light shut up, you've found the problem. If you're sure the coolant level is up and there's no air, the coolant sensor should be grounding the current coming from the harness. Essentially, unplug the sensor, take a test light, put it on the sensor plug, and the aligator clip on the battery (+) and it should light up.

It's a bit complex to bypass the warning cluster for the inexperienced, but you can make your own wiring with a relay and the stock sensor so that when the sensor grounds, the light stays dark. This is in the rare cases the rest of the system is screwed.

Think of the water level sensor as just a switch that has to be on for the light/buzzer to be off, which necessitates the previous paragraph.

 

Hi from Norway,

Unfortunately, the wire from the water level sensor is broken where the wire meets the sensor. On my 86 NA the sensor is on top of the radiator in combination with the overflow hose ( looks like this one: https://www.rx7club.com/attachment.p...1&d=1187736468

Can I just solder the wire "somewhere" onto the metal part of the sensor ?

If not, where can I get this kind of sensor ?

Comments appreciated !

Oivind

 

#1 most common way to blow your engine is a cooling system problem. Check and fix the sensor. If the problem is permanent then the sensor is disconnected or broken. If it comes and goes, the connection is loose or you have air in your cooling system.

 

I don't know that i would trust the soldering on it, even if it would work on the hex head.

Try http://www.mazdatrix.com/b8.htm
its only $35 usd and I'm sure they would be willing to ship to norway.
OR find a dealership somewhere in your area. I don't know what sort of precence mazda has in norway so you might need to try Britton. Your english seems good enough that you shouldn't have too much trouble.
OR find a used one in the for sale section of the forum, as long as you pay shipping most people wont mind to ship out of the country. (I think)

 

ok, well- I traced the wire, and found out that it was kinked, it had broken/cut a few of the wire threads from the wire that went to the sensor. I cut/ stripped, then soldered/ heat wrapped the connection.

PROBLEM SOLVED- thanks you guys, for any/ all help given