I'm trying to figure out some OBC issues for a 1986 325es. It's the 13 button unit.
First issue, there is no backlight. Switched with 2 other units, still no backlight. I found on another forum that pins 8, 9, and 10 appear to be the light, dimmer, and ground, respectively. Now, which ones are pins 8, 9, and 10? There's no numbers on the harness. If it's not getting power, where is it supposed to be drawing it from, so I can trace it to the source. And exactly how would I test? If it's getting 12v from 8-10 or 9-10?
Also, the AVG MPG reading is saying it's getting 10-15 mpg. It's a good running eta, so that's not even possible. The gauge below the tach is reading comparable mpg. So where do these guys get their calculations? I assume it's all pulled from the ECU.
First issue, there is no backlight. Switched with 2 other units, still no backlight. I found on another forum that pins 8, 9, and 10 appear to be the light, dimmer, and ground, respectively. Now, which ones are pins 8, 9, and 10? There's no numbers on the harness. If it's not getting power, where is it supposed to be drawing it from, so I can trace it to the source. And exactly how would I test? If it's getting 12v from 8-10 or 9-10?
Also, the AVG MPG reading is saying it's getting 10-15 mpg. It's a good running eta, so that's not even possible. The gauge below the tach is reading comparable mpg. So where do these guys get their calculations? I assume it's all pulled from the ECU.