rx7lives

My stock GSL-SE radiator needed coring out (last done in '97) so I took it out and got that done with no problem.
My issue is with the two sensors on the radiator.
The water level sensor in the top tank is no big deal as it's readily available.
My problem is with the one on the drivers, rear side in the lower tank. It has two wires and goes to a plastic connector. The wires both came off and while I might be able to re-solder them back after I grind away the phenolic but I'd prefer to use a new one if I can find it.

Does anyone have any deals? I'll owe you a beer.

I went to Bizrate.com and it appears they have what I need at a decent price but when you checkout, it tries to direct you to one of those 'free' 30 day deals that they hope you forget about on day 32 so I don't even know if it took my order.

I guess, if worse come to worse I'll go to a P&P and snag what I need.
Thank you,

DarkDrakeX

When i swaped to a aluminum radiator i looked into that sensor. From what i read and understood is its something to do with emissions. But the general decision i came up with is that it was unnecessary. Especially since one of the wires was broken for years anyways. Ive since removed it and had no problems.. So thats just my .02$. I would def like to know 100% what it is tho.

rx7lives

That's what I want to hear!

Put the rad in this morning, works fine, noticeable change in temp readings. I had to short the wire to the top sensor so I don't have to see the coolant level light until I get the switch. Since the temp gauge work, I'm assuming that sensor isn't for that.

flight_of_pain

No. 2 Water temp switch, connects to the ECU, and has to do with emissions.

Look in the FSM and all your questions will be answered

http://foxed.ca/index.php?page=rx7manual


Isaac

rx7lives

Looking at manual, it shows two temp sensors. Since my temp gauge still works, it's not that one. It shows that one connector goes to ground and the other goes to the ECU. Why it needs two sensors I don't know but this one is mounted in the lower rad tank. Maybe the ECU compares the outlet temp of the sensor behind the water pump and the one in the rad tank. The only other thing I can think of is that if the diff between the two sensors is not that much, it knows the rad is plugged or the water pump isn't pumping. That or it's to turn off the A/C compressor when it gets to hot.

Since I just replaced my O2 sensor which seemed to make it run much better and hopefully better mileage, I hope these are the last two, the one in the rad besides most places saying it's no longer available is the places that have it for $100. Partsgeek had it for around $75.

rx7lives

Once again, I'm an idiot. On Monday I ordered the top water level sensor and the bottom sensor for around $100. On Tuesday I decided to take a Dremel and see if I could solder the wires back on and once I ground down the epoxy, it had two easy to solder studs so I soldered the wires back and measured the resistance which was .68Ω then I put it in and noticed no difference. Yesterday I went to the pick and pull and got the bottom one which is around $75 new for $3.49. I measured its resistance and it's the same as the original I soldered in. I couldn't get the level sensor since someone had stripped it.

So now, the only sensor I need is the coolant level sensor and its already ordered so I wasted $75 bucks.

Once I'm sure the new sensor is the one I need, if anyone needs the bottom sensor, I'll sell the one I got at P&P for $5 plus shipping which can't be much or for trade.

j9fd3s

iTrader: (3)

the SWITCH in the bottom of the radiator is to turn on the emissions system, basically. without it the car will never go into closed loop, and never pass smog.

and its not a sensor, its just a switch, so it just turns on @65C

rrob311

do you know the thread size of the sensor?

Jeff20B

iTrader: (13)

12mm x 1.25... am I right?

rx7lives

It takes a 21mm wrench to remove.

It has fine brass threads that don 't taper.

According to my cheapo micrometer it's 11mm in diameter.

I don't have a tap and die set so I can't give you exact thread pitch but it looks like 7 threads per 10mm.

The place it screws into on the radiator is sealed (at least it is on mine) so you don't even need to plug the hole but I would triple check that.

rx7lives

It's a switch? Thanks you, it didn't seem to do anything however...

I put it in around 100°F water and it was still reading around 0Ω.

One thing I noticed or thought I did was that it seemed to surge on the freeway without it.

At the same time I was checking my A/C and although the compressor clutch engaged before, it didn't now. It worked when I jumped it to the +12v but I figured I would worry about it later.

After I re-soldered the wires back on the switch, the car seemed to run better. Then I started to look into the A/C issue and now it works, typical.

I looked in the FSM and it calls it a water temp switch. Connector BØ6 for 13b. According to the schematic, it connects to ground and the ECU but it doesn't say exactly what it does.

j9fd3s

iTrader: (3)

it gets explained in the training manual http://www.jimrothe.com/mazda/84_tra...raining_4b.pdf

rx7lives

Awesome link, Thank you!

I've downloaded everything and the printer is chugging away although my wife is going to wonder how her new printer cartridge needs replacing.