12V Relay Not Triggering

Hello :-) I just bought a VIPER 4806 remote starter and keyless entry. First i want to say thx to the forum, without you i would never have plugged the remote starter ! But now, i have a problem with my doors. I cannot plug it ! My car is an old 2000 audi A3. I've identified the locking and unlocking wire which need ground to activate. From the Viper, i have 2 negative 500ma output. I decided to wire relays, in order to have a ground to thoses door lock/unlock. https://www.the12volt.com/relays/relaydiagram46.html<----- is what i used. Problem : the relay does not activate. My grounds are OK. When i test the wire from Viper, if i activate the remote it shows me a 4-5V then goes down to 0. When i test beetween 86 and 85 i have 0.5V and when i activate the remote, it goes to 0.4V. I guess the ground is not strong enough as there is the remaining 0.4V ! and the relay doesn't activate Can you guys help me ? i've tried like a ton of things, but none work.....

Check from 85 or 86 and the other meter lead on ground of the vehicle. What do you get?

Beetween 86 where the alarm trigger is plugged and ground, i read 12V Beetween 85 where the +12V is plugged and ground, i read 12.5V Still this weird 0.5V...

If you connect wires directly from the battery to the relay coil (85 and 86), do you hear it click? Have you tried another relay?My ex once told me I have a perfect face for radio.

Yes, if i connect the +12V and ground directly from the battery, the relay click and works. I've tried 3 differents relays 12V 30A.

Do the same but this time arm and disarm the alarm and let us know what 85 and 86 do. The 12 v terminal should stay at 12. The one from alarm should go to ground. I am betting it is not. If that is the case try this https://www.the12volt.com/installbay/forum_posts.asp?tid=114792&kw=2n6491#556471

Ok i'll Check that as soon as i come back home. I ordered the TIP42 but it's a C not a G. I'll have it on monday or tuesday iguess. If it doesn't go to 0v do you have an idea why ? Known pb with viper ? Bad wiring ?

Either your 12 volt supply is not good, or the output of the alarm is damaged and can not provide the 160 milliamps of current needed to trigger the relay. Using the transistor will work if it is the latter of the problems. But you will need 2, 1 for lock and 1 for unlock. Tip42G is fine. I drew the C in the diagram because when it was drawn Radio Shack retail stores were a thing. That is the one they stocked.

As excepted if i use the remote it only goes from 12V to 11.8. Far from 0V!! Its weird... i looked everuwhere and it seems that i plugged all the grounds and all the 12V. Is it possible that i missed an important wire ?

Never ever needed relays on one of them. Extend lock time to close windows and roof if fitted. Make sure the green lock and blue unlock from the Viper go to ground when you activate lock and unlock on the remote. And put the meter away, use an incandescent bulb test light to test out puts from Viper, if they are OK use clip on test light to a good ground, probe to each suspect wire, make sure they lock and unlock. Try making your connections at the factory vacuum control unit, left hand rear just between wheel arch and rear light fitting.