I recently picked up a 91 Jetta that is having problems with the glow plugs. I am having two problems, and they are likley related.
1) The glow plug indicator on the dash does not come on, but I believe the LED is good. I did a test between L ad 85 on the glow plug connector, but I did not show any voltage.
2) The glow plugs come on and appear to stay on. I waited 45 sec and there was still power showing at the glow plugs.
I have replaced the relay with a new one, but still have both problems.
Any ideas where I should start looking? I have tried all the tests in the Bently manual for the glow plugs, but not sure where the problems are. Also, it mentions a fuse for the indicator, but I don't see one labeled on the fuse panel.
I'd suspect the temp sensor myself.
You can jump the glow plug light through the glow plug relay socket.
You can jump the glow plug light through the glow plug relay socket.
So do I go from power to the L terminal?
Which temp sensor is for the glow plugs? The one on the top or side?