1985 c4, wire question
Melting Slicks
Joined: Nov 2016
Posts: 2,256
Likes: 3,082
From: So Cal
2023 C4 of the Year Finalist - Unmodified
Coolant Temp, Manifold Air Temp, and Mass Air Flow sensors all ground at C1, D13. The splice is inside the car at the first branch after the harness comes through the firewall.
Rather than disecting your engine harness, you can check for continuity with a VOM between D13 and each of the three ground wires. Factory splices generally don't fail.
The Throttle Position Sensor has a dedicated ground. C1, C14. Gray wire.
Rather than disecting your engine harness, you can check for continuity with a VOM between D13 and each of the three ground wires. Factory splices generally don't fail.
The Throttle Position Sensor has a dedicated ground. C1, C14. Gray wire.
Thread Starter
Heel & Toe
Joined: Jan 2026
Posts: 15
Likes: 0
Thank you, I have ran a new coolant temp sensor wire and have only grounded it to d13 so I’m going to splice the other two sensors grounds into the coolant temp sensor wire ground, I use a few other sensors I gotta figure out and run wires to like the knock sensor.
