I performed pin by pin test on wiring according to manufacturers service manual, I have two seemingly ambiguous results, the first is 50.7 ohms of resistance in the F terminal of the APP wiring terminal and the main relay terminal A. I attributed this to the evap leak detection pump which shares this wire since that is at the top end of normal resistance between power and ground (terminals A & B) for that component. Is this correct? Secondly in the manufacturers (mazda) manual it refers to continuity between the ground terminal and the power supply of both the APP and the Evap leak detection pump as a short circuit. Isn't that a complete circuit and totally normal?
My car has an automatic transmission.
Hello. Generally speaking, most automotive circuits have very low resistance, usually less than 50 ohms. Unless there is a resistor, or sensor that acts as a resistor between the APP wiring terminal and main relay terminal A, then there may be some sort of wiring issue causing the excessive resistance. I would refer to a service manual or dealership for specifics on what the readings should be for the circuits in question. If the manual indicates that there should be no continuity between those circuits, then that may indicate that those circuits have grounds that are switched on an off, usually by the computer. If you are getting readings outside of normal range then it may be possible that there is an issue with your test leads, or a wiring issue with the circuits in question. Contact a professional mechanic, such as one from YourMechanic, if you want to have a technician inspect your circuits for you.
Have a car question? Get free advice from our top-rated mechanics.
Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%