Was fiddling with car stereo, accidently touched black and yellow wire, think I've blown something cos now neither stereo or central locking works! Please help.

SOURCE: Mercedes S320 central lock

The Key Fob needs to be syncronised to the car........Try this it works for many Mercs1....ensure the battery in the "Key Fob" is OK............Press either Lock or Unlock button for more than 1 second, the lamp on the fob will light if OK. Change battery if it does not illuminate!  2.....if battery on fob OK.......Re Syncronise the key fob to the car by:.... a brief press on either button twice and within 30 seconds turn Key to position 2 on the ignition lock 
Hope that fixes it...let me know?

SOURCE: Audi A4 Y Reg 2001, Central locking

reset you computer, do this by removing the positive battery cable for 10 mins.

SOURCE: Car alarm not activating central locking

It means that the remote is not passing the signal to the car . The alarm has triggered because the system has detected an illegal entry. Replace the remote batteries

SOURCE: peugeot 307 1.6 petrol central locking problem

leave ign off with key out 3mins disconnet battery 5 mins reconnett and press lock/ unlock repeatedly until locks cycle through to re sync try this any probs come back to me

Marvin

• 85242 Answers
• Posted on Apr 12, 2009

SOURCE: 91 Ford Tempo - New stereo won't work ... Please HELP

here is the radio's wire color diagram, u should be able to fix the problem with this info.Fuse box is on drivers side under the dash.
1991 Ford Tempo Car Radio Wiring Guide
Car Radio Battery Constant 12v+ Wire: Green/Yellow
Car Radio Accessory Switched 12v+ Wire: Yellow/Black
Car Radio Ground Wire: Red or Black
Car Radio Illumination Wire: N/A
Car Stereo Dimmer Wire: N/A
Car Stereo Antenna Trigger Wire: N/A
Car Stereo Amp Trigger Wire: N/A
Car Stereo Amplifier Location: N/A
Car Audio Front Speakers Size: 6 1/2′
Car Audio Front Speakers Location: Doors
Left Front Speaker Positive Wire (+): Orange/Green
Left Front Speaker Negative Wire (-): Black/White
Right Front Speaker Positive Wire (+): White/Green
Right Front Speaker Negative Wire (-): Black/White
Car Audio Rear Speakers Size: 5′ x 7′
Car Audio Rear Speakers Location: Rear Deck
Left Rear Speaker Positive Wire (+): Pink/Green
Left Rear Speaker Negative Wire (-): Pink/Blue
Right Rear Speaker Positive Wire (+): Pink/Blue
Right Rear Speaker Negative Wire (-): Green/Orange