Any thoughts here. My display is not showing any temperature. The original sensor had a broken terminal connection so i had just wrapped the wire around the post. This worked for years but when i did my head gasket, i decided to make it right (almost). So i purchased an aftermarket temp sensor. Worked for some time but now i get no reading at all. Thought the sensor was bad so I ordered straight from Hyundai. No luck! Checked the wiring by grounding the wire at the sensor and the display showed full hot, all bars lit up. So the wiring and display are good. I haven't checked the new sensor yet, but just confirmed the old one will change resistance with heat applied. Not sure where to go from here.
Is it a 2 wire temperature sensor or is it 3 wire. Some are pulse-width modulated so a few possibilities exist. Does the monitor set the level of temperature based on the sensors reading if a small resistor is installed between the wire and ground. Is it suppose to ground through the wire back to Battery Negative or through the Engine block back to Battery Negative. We are not there so can only guess and some new sensors even OEM have been faulty. Simon C
I would slow down and prove which style of sender the monitor wants before buying another one. Since grounding the wire drives the display full hot, the monitor and that signal wire are at least alive. A couple of checks I like on these older machines: make sure the new sender is a temperature sender, not just an overheat switch; compare resistance cold and then in hot water against the old sender if it still reacts; check whether it grounds through the brass body into the engine or has a separate ground return; and make sure thread sealant or paint is not insulating the sender from the head. I have also seen the little female terminal lose tension after being wrapped around a broken post for years, so it touches enough for a test but not enough when the machine vibrates. If you have a resistance decade box or a few known resistors, you can substitute them between the sender wire and clean engine ground and watch whether the bars move in steps. That tells you whether you have a sender curve mismatch, a bad ground path, or an intermittent connector instead of guessing by part number alone.
its a single wire sensor. I dont have the original anymore but i remember what it looked like. The replacement had a spade terminal for connection so i know it was oem. The replacement, purchased from Hyundai dealer based on my serial number has a single post similar to the original but requires a female butt splice type connector. Ill check the sender to ground today and confirm that resistance changes with temp.
resistance changes with temperature. Also, if i unplug the wire and then ground it to the body of the sensor the monitor completely lights up so the body to ground is good.
Nothing makes sense and nothing seems to be working. Ran the machine for about an hour. Nothing on the gauge until it completely pegged. I idled down and let it cool, and the temp went blank again. I think Im going to grab a cheap dial gage and sensor and install that to monitor engine temps.
So, another update. Installed the aftermarket analog temp gage and I do in fact have increasing coolant temperature. Of course it was a chore because the engine block has an adapter for the heating line which apparently is tapped to a -18 BSP (yeah British Pipe Thread) which is ever so slightly different than an NPT! So the update is my monitor has a clock and/or tachometer reading. Its been set on clock and when i switched to tach, nothing showed up. Great another broken sensor. Nope, confirmed Im getting 5v out of the sensor with the engine running. Now, the fuel gage works on the monitor and some of the other indicator lights. Im thinking there is something going on with the monitor, even though the temp pegged when the wire was grounded.