Hello people need some more help . Last week I replaced my thermostat on my 92 Bronco (5.8 351 engine) which was more work than I thought. I did that to see if I could get some movement from my temp gauge, which barely moves past the cold range even though i get heat in the truck. After i put the new thermostat in still no movement on my temp gauge which got me heated(no pun intended). After some searching on the site i find out that the ECT sensor might be the cause of my temp gauge not moving past cold. My question now is where is the ECT sensor and what else could cause the problem? thanks

 

The ECT sensor and the temp gauge sensor are two different animals.

The temp gauge sensor is a single wire resistance-type sending unit mounted in the intake manifold between the distributor and the #5 fuel injector. If you want to check the gauge before changing the sensor, ground the wire running to the sensor. This should peg the temp gauge needle all the way over.

The ECT sensor sends coolant temp info to the PCM only. Its mounted in a fitting immediately behind the water neck and has at least two wires extending from it.

 

ok I replaced the sensor today, still no movement on my coolant gage in the dash. My next move is to check the wiring on the gauge . I guess i better wire up and dashmount gage. Ford gages stink. Thanks Greystreak92

 

Yeah, thats the general concensus for most people. They don't give an actual reading, they give a reading based on change in voltage based on resistance. This is really the fault of the snesors/sending units employed. They are glorified switches. The oil pressure sending unit will give a "normal" range reading with as little as 5-10 PSI oil pressure! Well we all know thats NOT normal and is a problem. This setup doesn't get any better with age either. Electronic devices change their resistance value as they get old. Its the way electronic devices "wear", so the setup will inherently get worse as the vehicle ages.

 

is the normal way to replace the electronic oil pressure "switch" with a mechanical pressure sensor and then fit a new gauge in a pod on the dashboard? Is there 2 sensors for oil - one for the gauge and one for the loss of pressure warning light?

 

The one sending unit handles both the gauge and the red ENGINE light.

Check out my gallery for pics of where I mounted mine.

 

I have a three-gauge "A" post mounting pod with Autometer Ultralight coolant temp, oil pressure, and vacuum gauges installed. B-day present from my lovely bride. I have the OEM gauges still in the dash but they are non-functioning right now because I swapped sensors/sending units to make the "good ones" work.

 

Just curious, is it possible to hook up the mech. gauges and still have the dummy gauges work?

 

Yes, there are adaptor fittings you can get to provide a split sensor setup. Check with your parts store or better yet, the manufacturer of the aftermarket gauges you will be using.

 

You can only split the oil pressure, not the water temp. The tip of the sender has to stick out in the water flow. If you use a T, like you would with the oil pressure, the coolant will get trapped in the T, and the temp won't be accurate.

Also, consider using electrical gauge as opposed to the mechanical gauges. I can't seem to get mechanical water temp gauges to work for more than a few months in my truck before they die. With a mechanical oil pressure gauge, you have to worry about the line leaking or rupturing. I have mech. gauges now, and I'm in the process of swapping them out for electrical ones.