I've been getting a very intermittent no glow plug light in the cluster with hard starting. To help with troubleshooting, I have rigged up a light bulb to the violet wire at the glow relay connector and another bulb at one of the glow plugs so when the problem occurs, I can pop the hood and immediately see what's going on. Since I've rigged it, the problem has not occurred lol.

Anyway, this is how my 85 behaves:

key on - both bulbs on (voltage at violet wire and glow plugs)

turn key to crank starter- both bulbs on (voltage at violet wire and glow plugs)

release key, engine started- violet wire bulb on, glow plug bulb off.

Is this how yours behave? Please state year/ model.

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85 300D turbo pristine w 157k when purchased 167,870 July 2025
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked