75,

You mechanic doesn't what he it talking about. Parallel GP will work with or without a relay if both ways are wired correctly. I know this to be true because I replaced the series GP in a '64 190D with parallel GP 20 years ago and it worked great. Less time required waiting for GP to heat and engine started quicker. I made adapter bushings from loop style GP so parallel GP could be used in the 190D engine.

Its true the parallel GP were not made for the 240D engine but that doesn't mean that they can't be adapted to it. U can also control how long you have the Parallel GP energized by how long U pull out the "gorilla knob".

The relay was added to update the old obsolete "gorilla knob" with a modern system where you only had to turn a key to start and stop the engine.

Since the GP are in parallel, it doesn't matter which one U connect the emergency jumper wire to. Use easiest one to get at.

Yes 10 gage wire would work better if it fits in the terminals.

I don't understand what U mean by U replaced the resistor with a light bulb.

You can contact me at MrP8888 on Yahoo messenger.

P E H