One quick question - light

Does Audi 90 typ 81 has a relay for long and short light? There are fuses for individual light but whether it has the relay for the lights? Thanks.

No, it doesnt. The full current for the headlights goes directly over the light switch, which doesnt only cause a significant voltage drop, but also kills the light switch sooner or later.

You can easily convert it to a relais circuit though. Either you dig into the circuit diagrams yourself (available at http://www.typ8185-forum.de/ in "Stromlaufpläne & Elektrik -> Stromlaufpläne typ 81/85") and build something, or you buy a complete, plug&play-installable set. I believe the user "Fünfendercoupe" offers those sets for a relatively small price.

Light switch on these models audi cited as a weak point, and precisely because electricity goes directly through the switch ... So I'm going to buy a new switch and install relay for long and short light ... why Audi made this failure and did not install the relays for the lights ... they are installed a relay for stupid horn ... for me it was a big failure ..