CHIPMUNK BASIC BREAK IN GOTO SERIAL

Good news from the Internet: One of the places that claim to have the chip identify it as a 5-channel gauge driver with serial link. That will let me test the switch to see if it truly is open, once I am certain of of the lead identifications. The other treasure from the junk yard was the pigtail. On the other hand, the Malibu was right up in front at the radiator and easy to access. It can be reached from the top, but most everything is done by feel. Ford had the foresight to bury the switch at the rear of the engine compartment just at the transmission tunnel. That is a more difficult trouble shoot as the PCM to which the wires go is buried under a bunch of stuff. Cutting that off and attaching wires to it is one of my next planned steps.Ģ) A d*** chipmunk chewed the harness wires - only the 5V reference needs to be broken - and the link is broken.

Got the used sensor just for its male end. Plausible causes:ġ) Maybe my connections to the plug were faulty. I did testing the harness as recommended by a reputable (?) automotive 'diagnostics expert' on YouTube and came up negative - meaning all of the voltages that were supposed to be on the 3-pin plug read zero. I just want some confidence in my identifications. The Ford factory switch does have a protrusion to open a Shrader valve, if one is present.Ĭlick to expand.That is exactly what I am considering. Does anyone know where Ford does that? Haynes' directions say the system must be emptied before changing the switch. Is that correct?Ĥ) Some cars have a Shrader valve on the port to which the gauge attaches. Are those assignments correct?ģ) The signal seems to be a DC voltage from 5V (no pressure applied) to something less than 5V depending on how much I press on the ceramic disk (white thing below the PCB). The white wire was added to allow testing to chassis ground - there are no direct connections to that ground although, there are some capacitors that connect to it (one is obvious in the picture).ġ) Does anyone here have access to that datasheet?Ģ) I have identified the three leads on the Malibu switch as RED/BLK = Signal, GRAY or GREEN (can't tell) as Reference voltage (5V), and BLK as the Return Common. The chip is labeled MLX12103EB (Melexis?) and is apparently a real number, but I cannot find a real link to its datasheet or pinout. Here are the Ford schematic for my make and model and the inside view of the one I excised from a Malibu: I pulled one off an old Malibu yesterday for testing. The gauge is a 3-wire gauge and is used on a lot of cars, including GM. Instructions I found for testing it in circuit on the Internet are baloney. Refrigerant pressure is 90 PSIG static by actual measurement. Pressure reads ad '499.7' PSIG from the scanner, which I believe corresponds to open circuit. My scanner shows an error for the high-pressure switch. A lot of Internet experts say it is probably the temperature sensor on a receiver under the dash. A/C went out on my 2012 Fusion last year, 600 miles over warranty and got no help from Ford.

Chipmunk basic break in goto