[dabnis]

VW diesels I had used a solenoid with a time out device. IIRC, a long time ago, they were fused, at least 50 amps, in the main fuse panel, I think? If powered through a solenoid the fuse could/should be ahead of it. Not sure if glow plugs are subject to shorting? Going open? yes.

A shop manual may provide details. If it shows a fuse, probably be a good idea to add one?

Paul T