Voltage Regulator Connections - Mystery Box

[Pawel66]

Does anyone know what is the marked box for exactly? It has 3 spade pins, same as the VR, and the VR plug is connected to them, then it has the wire and plug coming out of it, plugged into VR, identical to plug coming out of harness to the VR (just has one wire D+ while the plug from the harness has 2 wires, as it should).

Looks like it is just extension - just by looking at the connections. There is 0.5ohm resistance between "in" set of spades and "out" set of connectors in its plug (but it might be just measurement error).

I do not see it on the wiring diagram. It has the dedicated space on the VR mounting bracket.

What is it for?

[Pawel66]

More to this thread:

With the Bosch VR that I bought ca 5 years ago, I have on battery posts 14.1V while engine is running, idle or higher rpm, regardless if I connect VR through this box or not.

I installed a new Hella unit, just to check and I have:

- 14.9V at idle with voltage going up as rpms increase (saw 16.5V and stopped increaseing rpms) - this is too much
- 14.1V and steady when I connect Hella through this box (correct value)

What is this thing?

I assume the voltage, as per Technica Manual, should be 13.5-14.5 with engine running.

[WRe]

Hi Pawel,
I really don't know what kind of box you have in your car but it doesn't seem original.
My guesses:
- Maybe it's an electronic voltage regulator build in if it's a box and not only a connector
- Maybe it's a cut-off relay or a connector for a cut-off relay to start high power user (e.g. heated rear window) only if the engine is running
Sorry!
...WRe

[Pawel66]

Thank you for some hints!

[WRe]

Hi Pawel,
Your mystery box could be a radio interference suppressor.
...WRe

[Pawel66]

Bingo!

Thank you!