Cleaning up 300tdi electronics and wiring

[Landi]

Gday, im the second lucky owner of a 98 300tdi and have very little understanding of electronics or wiring. Ive had the truck 6 months and have got a few questions regarding the car's current set up.

1. It has a dual battery system in the seat box with what i think is a piranha isolator. Ive checked both batreries with a multi meter: the main is showing 12.58V, and the second only 11.3V. I had an auto electrian look at it a few months ago and said the wiring was around the wrong way and the isolator was broken, so they apparently rectified it. Whats going on with the second battery?

2. It has an electronic rust prevention system fitted with a module with a red light under the seat box. I want to uninstall this. What other components are there to the system?

3. It has an Immobiliser fitted which i'd also like to uninstal. Is this easily achieved by following the wiring from the dash?

4. It struggled starting today after not being driven for a week. Is this normal? Possibly because of the Immobiliser and ERPS running the whole time?

Ideally i'd like to take it to an auto electrician and start from scratch, and get rid of all the old wiring and keep only what i need. But this would cost a fortune im guessing and i'd also like to learn about it all so i can understand my own truck a bit better

[VladTepes]

The EPRS thing must draw some current then, because I can leave my Tdi 130 sitting for 3 weeks and it starts up readily.

[Robmacca]

It will come down to how those devices are wired.... whether to the main or the aux battery. Not sure on the immobiliser but with the ERPS device, just pull the fuse for the time being. I assume the immobiliser just isolates supply to the injector Pump? There's no real electronic's in a tdi300 defender from the factory from what i've read....

[dero]

I have no idea about your dual battery set up , But I have a Traxide system that works well .
I bypassed my immobiliser in the carpark at the boat ramp , it failed whilst launching , very inconvenient & embarassing , but as I recall it was not hard to do .
Other things I have done are removing the headlight relay that is buried in the dash & putting in headlight relays [ the easy way ] both of which are explained if you search the forum & I would highly recommend both .