Hey guys, I was replacing the temperature gauge sender on my 2001 Ford Explorer 4.0. The temperature gauge stopped working and I inspected the connector for the sender and sure enough it was physically damaged/cracked. I ordered a new connector, stripped the coating off the wires for it and then cut off the damaged connector and did the same to the existing wires that the old sensor was connected to.
This photo shows the coating-stripped wires of the new connector. They are both copper and both have black coating.
This photo shows the wires with the coating stripped off for where I cut off the old broken connector. They both appear to be copper wires as well, however one wire has black and white coating and the other has red and white coating.
Replaced the connector and new sending sensor from motorcraft. Screws into the engine block. Twisted the wires together and no power to the gauge at all it seems it’s just stuck all the way down on cold. I’m data streaming using a scanner and the ECU is able to read the temperature correctly and shows 197 degrees but the gauge isn’t working. What gives?
With some engine configurations, the coolant temp sensor for the dashboard gauge is a different part, installed in a different location, than the one used by the drivetrain computer. That’s the case for my OBD I Corolla. And in some configurations there are other temperature sensors; e.g. one just for the cylinder head. Suggest to review the service data for your particular engine. Maybe the one your removed isn’t used for the dashboard gauge.
George, you are right. My car has 2 similar looking sensors that screw into the thermostat housing. I was originally replacing the timing chain tensioners as preventative maintenance and to get to the front one under the hood I had to remove the thermostat housing which required removing the entire upper manifold. While I was in there I replaced the thermostat, the o ring for the thermostat and both sensors because they were only $80 for everything from the Ford dealership. However I did notice the gauge sender connector was cracked (on the left in the photo below) so I replaced the wiring harness for that as well. ALTHOUGH the gauge was working fine before.
The one on the left is for the gauge and the one on the right is the coolant temp sensor. I replaced both with motorcraft parts and since the ECU is reading properly using a scan tool that tells me the sensors are correct and in the correct spots. So if the gauge was working before then does that have to mean the gauge sender sensor they sold me is defective? I guess I should try putting the old sensor back in but that was a PITA to get to because there is ZERO working room on these 4.0’s
I expect that’s what you are going to have to do to get to the bottom of it. You could consider yourself lucky. My OBD I Corolla has 5 gadgets that screw into the cooling jacket: coolant sensor for computer, for gauge, for purge valve, for cold start injector control, and for the radiator fan. The sensors are often just variable resistors, so worth a try just measuring their resistance w/DVM while you vary the temperature by blowing warm air from a hair dryer on it.
I didn’t realize that a 90’s corolla could be that complicated haha. I am 100% for doing preventative maintenance and in this case I had to remove both sensors anyway to get a socket on the timing chain tensioner so since they were already out anyway I figured might as well replace them since they’re 20 years old and new OEM parts are cheap
