Volvo Starter Kill Radio

Nobody on the audio forum could answer this so lets see what you guys got. i'm workin on a 91 Volvo 240, and it woulda been a simple head unit install, but this one had an amplified system. So i ran new wires to each speaker and used the factory harness for power (except the constant as it was only reading 4 volts, so i ran a new one to the "hazards" fuse for a constant 12v) Upon completion, the car would turn over but not start. The cust said "yeah that happened to my bro when he had another shop try to put one in. they said it cant be done"    !!!!!!!!!!!!  GEEZ!   Anyway, i put the stock radio back in and the car started right up. So i went to tidy the dash up until i could post this on here and now the damn car wont start AGAIN!! all connections are solid and its all factory like again....The radio reads "code" but nobody knows the code. I've never seen an antitheft radio prevent a car from STARTING, what gives?  Anyway, is there a way to put the Kenwood back in and bypass this starter kill system?  Or at the very least, get the damn car to start at all?   ANYONE!!!!!!!!!!!!!Mitchell Whitney, Installer/technician

Mainstreet A/V

I've replaced the radio in those cars before without issues. Possible you blew a fuse? The 4 volt constant wire is making me think something is wrong....

nope. tested all fuses. test ok (which is good, cuz theyre those stupid little German fuses, which it seems nobody in the state carries). Yeah, i thought the 4v was weird too, but being a foreign heap of crap, ya never can tell.....Mitchell Whitney, Installer/technician

Mainstreet A/V