jdulle
Veteran Member
So my new to me grey 97 b4 was a little hard to start in the cold so I replaced the glow plugs. That didn't seem to help much, so I took off the harness to check the voltage. I got voltage to all 4. Then I put it back on, and it was old and falling apart and the check engine light came on for the glow plugs. So I bought a new harness and put it in. Still the light comes on after running the engine for 20 secs or so. I checked the voltage at the 2 wires, and it was 9.2 v in one and 9.6 in the other. I am guessing they should be the same? I then checked the glow plugs by voltmeter between positive battery and top of each glow plug and got the same battery voltage (12.39). So what could it be? The wires before the harness? The battery is pretty old and doesn't have full CCA so I will be replacing that soon, which I guess could be the issue.