Continuosly blowing a fuse!!

[DUFFER]

My mates 06 mazda 5 was broken into. The ingnition barrel was damaged.Also a new key had to be ordered. But now every time the car is started a fuse blows!!. It was linked to a computer to check the CPU and it came up as a relay failure which was replaced. But the problem keeps re-occuring any suggestions???

[StealthWyvern]

Were the wires cut or anything? I'd start by checking the wires for damage. I assume they replaced the ingnition colum right.

[DUFFER]

Dont really know the full details!. The guy has the master key and sent it off to obtain two ordinary keys. The car was a repo and and the origianl owner apparently damaged it after it was taken?????...any way he hasnt programmed the phobs does this need to be done before the immobiliser will deactivate?...also the CPU fault came up and a mechanic bypassed the relay and apparently got it started but the starter stayed on NOT A GOOD IDEA I KNOW!...so he replaced the relay at a cost of £90 and now when the key is turned the lights come on but when the the starter is activated the fuse blows. The wiring seems fine. Is this how an immobiliser would respond if the wrong chip is in the new keys? So many questions i know but we are really in the dark here!!!

[StealthWyvern]

I do not know how a immbiliser works however i seriously doubt they are supposed to blow a fuse... still sounds like a wiring issue to me. Like somethings shorted out or something

[DUFFER]

I think ur right, it def shouldnt blow the fuse.any other suggestons?

[StealthWyvern]

wiring may seem fine however something doesnt sound likes its wired up correctly.

[DUFFER]

could it be the relay?

[StealthWyvern]

Didn't you say he replaced the relay?

[DUFFER]

Yes but I am thinking when he bypassed it this may have upset something else?

[DUFFER]

When the fuse blows the fault coming from the CPU is "468" Relay failure...but this is not a mazda computer.