Headunit wiring problem

[xcessive]

Hi

I bought a new headunit today and tried to wire it in.
I have a ISO wiring loom so i assumed it would just be a case of unplug the old headunit, unplug old wiring harness from ISO and attach new one in place.

Well that didnt work.
The headunit wouldnt turn on at all.
After a bit of fiddling it does turn on for about 2 seconds then switch off.
What could be the problem??

 

[Firestar_3x]

Bad connection, just blown a fuse due to bad connection / live touching earth...

 

[xcessive]

Bad connection, just blown a fuse due to bad connection / live touching earth...

I havent done any wiring though.
All ive done is plug the existing ford connection into the ISO and the headunit into the ISO.
If i had blown a fuse would it even power the headunit?

I think it maybe a dodgy earth.
Where is the earth on the car?

The car in question is a 2000 Ford Fiesta Zetec S

 

[The Running Man]

make sure u plug the ariel in before turning it on, mine was earthed through ariel,a nd it wouldnt switch on till we plugged that in!

kept us stumped for a few mins..

 

[xcessive]

make sure u plug the ariel in before turning it on, mine was earthed through ariel,a nd it wouldnt switch on till we plugged that in!

kept us stumped for a few mins..

LOL good point!!
I never plugged the aerial in just the connector that came from the ISO loom

 

[xcessive]

LOL good point!!
I never plugged the aerial in just the connector that came from the ISO loom

Just tried plugging in the aerial as well as the main connector and still no luck.
What else could it be?
It could be an earth problem, how would i check this out? A mate of mine earlier put a multimeter across the ISO connector (the permanent power connection) and he said that it was reading low. All i could see was the number 1 on the screen of the multimeter. Is that badly low?
How can that be fixed?

Thanks