Wiring to fuel filter question

[chrishelakdo110]

Original fuel filter for 2.5 NA has been upgraded to the system for 200tdi. There are some electrical additions here also, not sure what they are supposed to be. I’m sure someone has seen before and can give me an idea. Blue wire is spliced in from purple on harness, brown goes out to relay seen in top right of pic. I have no idea if this even works, whatever it is. Thanks for advice.

 

[javelinadave]

I love demystifying bastardized trucks. I feel like a Defender Myth Buster, Dave Savage or Dave Hyneman.
I have actually seen that before. I'm 99% sure it is a German companies fuel heater. You can always pull it off and run 12v to it to see if it gets warm.

 

[chrishelakdo110]

Interesting. Thanks. If you like debugging old wiring, take a look at my other post under starter switch. I’ve got all sorts of mysteries to sort through. The more I dig, the more I find