Temp sending unit?

[rustang87]

Alright. How many are there? There are 2 - 2 wire connecters. One is on the heater tube, i beleive it goes to the computer. There is another behind the 5th cyl injecter. Does that go to the guage? Or is it the one wire boot that is in front of the 5th cyl injecter? I need to test the temp via volt meter. Jrichker said to probe both wires while sender was attached.
The connecter has a black/blue and green/purple wire going to it. And the boot on the other side of the injecter is a single red/white wire.

Which ONE is the temp sending unit? What are the others then?

 

[HISSIN50]

The temp sending unit is the single wire unit on the driver's side.

 

[rustang87]

There are two larger 2 wire connectors: one on the heater tube, one on the lower intake behind the 5th cly injecter. The one on the drivers side has a black/blue and a green/purple wire. is the one on the heater for the computer? Is the one between the 5th and 6th cly injecter for the guage? Or is it the single red/white wire with the rubber boot on the end in front of all the driver side injecters? I want to check the temp with my voltmeter. Jrichker said to probe both wires while they were connected.

Soooo, which one is the temp sending unit? Which one do I probe? What are the other 2 units?

 

[bretamo]

I've never seen a wire "on the heater tube", so I cannot comment on that.

The stock lower intake has the temp sending unit by the 5th cylinder. Some intakes also have fittings at the rear of the lower intake by the 8th cylinder.

For testing , use the one by the 5th cyl.

 

[88mouse]

the one on the heater code lines are for the computer and the other is for the gauge.

 

[RYC CUKR]

pretty much what mouse said. The larger connector behind the injector on the #5 runner is the ACT (air charge temperature) sensor.

 

[rustang87]

what is the ACT and the ECT ? The 2 wire connecter by the 5th runner and the one on the heater hose: what are their purposes?

I am assuming that the Autometer guages replace the single red/white wire spot...

 

[HISSIN50]

ACT/IAT = Air Charge Temp sensor/Intake Air Temp sensor (same thing, two different names). This sensor does as the name implies - lets the puter know how dense the incoming air is.

ECT = Engine Coolant Temp sensor. Simply relays coolant/engine temps to the puter.

Both sensors are used for fuel trim, etc.

The Autometer sending unit would indeed take the spot of the OEM one wire temp gauge sender. The OEM sender can be relocated elsewhere to keep the stock gauge active.

 

[rustang87]

hmmmmm, I wonder what Jrichker meant by probing both wires of the unit when it is only that single red/white wire...
Thanks for the help guys.

Oh yah, since I bypassed the heater core, can I get rid of the hard coolant lines that the ECT plugs into? Can I move the ECT somewhere else?

 

[Mustang5L5]

I'm gonna merge the threads here. We don't need two threads on the same topic by the same poster

 

[88mouse]

hmmmmm, I wonder what Jrichker meant by probing both wires of the unit when it is only that single red/white wire...
Thanks for the help guys.

Oh yah, since I bypassed the heater core, can I get rid of the hard coolant lines that the ECT plugs into? Can I move the ECT somewhere else?

yeah you can remove the hard lines but you will have to put that ECT somewhere not sure but it may beable to on where the other sending unit was. then put your after market gauge where the hard lines where.

 

[rustang87]

awsome, thanks for spelling it out for me... I needed that.

So, do I probe the 2 wires wires off the ECT to use the conversion. Volts - Degree's F.

 

[88mouse]

not sure maybe you can pm jrichker and get a little more detail as far as that goes. ( he is the man to talk to about wiring).

 

[RYC CUKR]

hmmmmm, I wonder what Jrichker meant by probing both wires of the unit when it is only that single red/white wire...
Thanks for the help guys.

Oh yah, since I bypassed the heater core, can I get rid of the hard coolant lines that the ECT plugs into? Can I move the ECT somewhere else?

I believe that the ECT is a 3/8" NPT thread and the hole in the intake for the coolant hard lines is a 1/2" NPT thread. I picked up a brass bushing from the hardware store and reduced the hole in the intake down to the same threads as the ECT and then put my ECT in. Works like a champ.

 

[jrichker]

hmmmmm, I wonder what Jrichker meant by probing both wires of the unit when it is only that single red/white wire...
Thanks for the help guys.

Oh yah, since I bypassed the heater core, can I get rid of the hard coolant lines that the ECT plugs into? Can I move the ECT somewhere else?

The ECT is located in the heater feed tubing on the passenger side and has two wires.
The wire colors are lt green/yellow and black/white.

The ACT is located in #5 intake runner on the driver's side and has two wires.
The wires are lt green/pink and black/white.

The water temp sender for the dash gauge is located on the driver's side and has a single wire.

Probe the ECT to get the temp readings if you want to check the water temp gauge for accuracy.

Pin 25 ACT signal in. at 50 degrees F it should be 3.5 volts. It is a good number if the ACT is mounted in the inlet airbox. If it is mounted in the lower intake manifold, the voltage readings will be lower because of the heat transfer.

Pin 7 ECT signal in. at 176 degrees F it should be .80 volts

The ACT & ECT have the same thermistor, so the table values are the same.

Here's the table: The values are +/- 15%, so don't get worried if your readings vary a little bit.

Voltages are measured across the two connector pins of the sensor with the sensor connected. Some safety pins used to probe the connector from the rear will be helpful

50 degrees F = 3.52 v
68 degrees F = 3.02 v
86 degrees F = 2.62 v
104 degrees F = 2.16 v
122 degrees F = 1.72 v
140 degrees F = 1.35 v
158 degrees F = 1.04 v
176 degrees F = .80 v
194 degrees F = .61
212 degrees F = .47 v
230 degrees F = .36 v
248 degrees F = .28 v

Ohms measures at the computer with the computer disconnected, or at the sensor with the sensor disconnected.
50 degrees F = 58.75 K ohms
68 degrees F = 37.30 K ohms
86 degrees F = 27.27 K ohms
104 degrees F = 16.15 K ohms
122 degrees F = 10.97 K ohms
140 degrees F = 7.60 K ohms
158 degrees F = 5.37 K ohms
176 degrees F = 3.84 K ohms
194 degrees F = 2.80 K ohms
212 degrees F = 2.07 K ohms
230 degrees F = 1.55 K ohms
248 degrees F = 1.18 k ohms

 

[rustang87]

good stuff, thanks for the help.