There are 2 sensors in the back of the coolent filler neck and I was wondering what they are for , The is also one in the front. Which is which, water temp, water level, fans??

 

The two sensors on the back:

1. Top one is the level sensor
2. Bottom is the thermoswitch (which can be switched for the Miata one).

 

Actually the one in the front is the coolant level sensor, the two in the back are the fan switch(thermoswitch) and the other is the coolant temp sensor for the ecu, not for the gauge. I forget which one is witch.

 

Opps, yea, the theromsensor is on top, the thermoswitch is on the bottom.

 

so do I need to pull one out and re-thread it for a after-market water temp guage? The one with green connector is for what?

 

Most people just leave the stock sensor there. Unless you plan on replacing the gauge inside the dash, just leave it. Depending on the gauge/snesoe, you can either tap a new hole or ones like the Autometer Temp sensor can replace the hex bolt on top of the housing (requiring no drilling).

 

The autometer has a 1/2 inch pipe thread, it will need drilling, nut know biggy. We will be drilling it tomorow, and putting the motor back in the car. I have to get a few other things though(studs,nut, bolts ect..damn engine builder) . The sensor in the back bottom of the water pump housing doesnt have anything to connect to it, will this be ok?

 

Which Autometer do you have? This one?:

http://66.216.67.51/product.asp?0=212&1=270&3=390

If so, there is no drilling required. You remove the hex bolt on top of the housing and insert there (I installed mine there not too long ago). Here's a pic, but not of mine:



As far as the sensor on the back bottom, that's the switch to turn the fans on. If you have done the fan mod, it's probably not a problem. If you don't have the fan mod, you might want to get that connected.

 

I was told that it was best and most accurate to put the sensor on behind the the thermostat becuase it would only read accurate when the thernostat was open(before the thermostate). any opinions?

 

Any place on the thermostat housing is going to be that way basically.

Take a read here:
https://www.rx7club.com/forum/showth...threadid=74058

https://www.rx7club.com/forum/showth...hreadid=179123

A good discussion here:
https://www.rx7club.com/forum/showth...hreadid=187766

Good luck!

 

ok, i hate to ask a question that you've prob heard a zillion times but i've searched and i havent found the right answer to my problem.. but since this thread is similar, i might as well bring it back from the dead and ask here instead of making another thread.

anyway

i have a nordskog LED digital temp gauge, coming out of the back of the gauge is 4 wires, red, black, purple, and blue..

in the instructions, it said the red is the 12 volts, black is ground, purple is for dim (optional) and blue is to temp sender..

all my understands for these wires are ok except for that blue wire which needs to go to the temp sender..

now this gauge didnt come with any threaded nipple or anything.. now my question(s) are, where would be the best place to put this blue wire and how, should i put it in a new location? how can i connect this thus being only a single wire?

please help

thank you and sorry for the long post and bringing this thread back

 

bump

 

without this thread I would have most likely forgotten to reattach mine...oh boy. Thank you 93redfd

 

Do not remove that thermosensor. It is used by the ECU.

The single black/red wire one is the thermoswitch used by the fan relays.

There are 3 seperate systems essentially.

1. Control (ECU, fuel injection, etc) sensors.
2. Cooling system/Fan control - the thermo-switch and relays.
3. Warning system (the water temp gauge, located towards the rear of the engine on the left).

 

I think your going to have trouble with that since it isnt set to work with the stock water temp sensor. But lets just say it was it goes to the single wire coming off driver side of the block, down and a little to the left of the oil filter and next to the oil press sensor.

~Luke

 

I think your going to have trouble with that since it isnt set to work with the stock water temp sensor. But lets just say it was it goes to the single wire coming off driver side of the block, down and a little to the left of the oil filter and next to the oil press sensor.

~Luke

 

You need to buy the temperature sending unit for that guage, then you mount it something like the picture that majik posted and connect the blue wire to it.

 

Since the stock guage is virtually useless (even moreso if you're adding an aftermarket guage), I'm recommending pulling the sensor on the block and replacing it with whatever sender your guage comes with. Leave the old one hanging if you want, it'll still move up a little, and your new guage will have the most accurate readout possible.

 

Aftermarket temp sensors should be installed in an area past the water-pump outlet side. This will give the hottest average readings and as so is the best place for it.

 

Good point, I'll stop suggesting that then.... would the side hex bolt on the housing work? I don't have an airpump, and my sender is too tall to fit under the filler cap with the necessary adapter, but does the side one go into the coolant as well?

 

so where shall i place the sender? by the oil filter location?

 

Well, the oil filter location is the temperature going into the engine, not out. Also, it's very hard to get out....VERY hard.


I opted for the side hex bolt with some adapters from Home Depot. The sensor isn't directly in the stream of things because of the adapters, but it's very close, and should be as accurate.

 

placeholder for second pic

 

ok guys, i know im a pain in the *** but im doing this job this weekend so let me clear things up

i have the nordskog led digital temp gauge, i bought the sender too so i have everything..

can i place the sender here?



or here?



prob the same thing right? which job is easier?

 

https://www.rx7club.com/showthread.p...hreadid=247152