So today I was taking out all the dry-rotted crappy coolant hoses, and I was gonna take out the thermostat to get it replaced, but I'm kinda confused. Here are some pics and questions.



This was between two coolant hoses. I believe it is the temp sensor, but the temp never goes up on the after-market gauge or cluster.



Inside that thingy.



Nothing seems to be connected for the thermostat?



This temp sensor seems to be okay, but the temp never goes up on cluster or after-market gauge.

 

I also checked the thermostat, and it looks perfect, it's all shiny. But why would nothing be connected for it? I'm just really, really confused. I know the actual place to connect the temp gauge is on the driver side of the rotor housings, near the transmission, and there is a wire connected to it, I will do a more thorough following of wires this afternoon to see where everything goes. I'm just confused about the thermostat.

 

I'll take a lighter later then and put it on the tip of that thing that was in between the hoses and see if the temp goes up at all somewhere, but I doubt it will because nothing ever went up when I was driving the car.

 

the first three pics are of some added sensors..the third pic is a water thermo sensor from an EGI engine, 84+. it detects coolant temp and sends the signal to the ecu for idle speed adjustments based on coolant temp. use only a mazda thermostat. they are brass in color and have a jiggle pin (which is required) and that jiggle pin should be facing the 12 o'clock position when reinstalled.

the fourth pic is the coolant level sensor that threads into the top of the radiator.

 

Temp gauge for the water sensor (that uses the stock gauges) is on the rear housing spark plug side IIRC.

 

^and next to the oil pressure sender.

 

In the 3rd picture, shouldn't there be a wiring connecting to that spot? Or since I don't have an ECU (I haven't seen one or found one), should there be nothing connecting to it? And do you reccommend I get rid of the in-hose temperature sensor? I'm going to follow where the wire leads to when I get home.

 

I saw that there is a wire connected to it, but neither of my temp gauges work. I will follow the wire when I get home and see where it leads to.

 

its an FC water pump, so that isn't used for you. it does work great to keep water in the engine though.

the other sender in the pipe, is for an after market gauge

 

Ohh, okay. Thanks for the clarification, I didn't know what they were for.

 

PS; don't use a lighter to test water temp sensors... way too hot! Use boiling water instead.

 

Well I did my wiring following and here is what I got. I followed the in-hose temp gauge to find out it goes to the after-market gauge. I checked with a lighter to see if it takes readings, and no luck. I then followed the random temp gauge in the engine bay to find it goes to the after-market oil temp gauge, but the after-market oil temp gauge gets a reading when I'm driving the car. ??? It might be possible that it's so close to the headers that it gets a reading, but when I used a lighter to test it, nothing came up for it, and I don't think that it would get to be over 150 degrees in the engine bay, because when I open the hood when it's running, it's definitely not 140 or 150 degrees. I also found out that I got the oil pressure sender mixed up with water temp, so the water temp gauge doesn't have anything connected to (I mean the stock water temp gauge). So I then followed the after-market water temp gauge wire, but the wire I believe is for the light bulb, and that wire led into the wiring harness.
So as you guys can see, this car is a wiring night mare. If anybody has any suggestions or help, lemme hear it. I'm most likely going to be getting over my friend's dad who is an electrical engineer and see what he thinks of the mess because this is way beyond my head. If he can't figure it out, then I'm not sure what's going to happen.

 

Quick question, it would be a great help if it was answered fast, I'm ordering stuff tonight/tomorrow. Since my water pump is from an FC, is the thermostat different?

 

And the temp sender in the picture above, doesn't look anything like this 1983 rx7 temp sender.



So I'm quite confused about that.

 

the thermostats are different. 79-85 are identical, 86-88 are identical, and 89-95 are idenical.

the temp sender you have pictured in post #14 is the coolant temp sender located under the oil filter, just ahead of the oil pressure sender. the coolant temp senders are identical from 79-80 and 81-88

 

Thanks a lot for the help. I will try and match up the thermostats then.

 

i have an aftermarket temp gauge with prob in that location in the back of the pump housing.

 

How is that set up? Pics?

 

the temp gauge came with several different adaptors so i used whatever fit. needed to use teflon tape too. i'm at work right now so i'll have to find u some pix later.

 

Aite, sounds good. I want to see how it's set up, I don't like the mid-hose sensor look.

 

anything else let me know.

 

Thanks.

 

Bumping an ancient thread to give thanks. Mine's been inactive and I couldn't figure out how/why... You just saved me the hassle of tearing apart my cluster for nothing!