Ford Mondeo 1999 auto petrol - Fuse keeps blowing

Honest John Back Room » Technical matters
View Threaded
Sun 31 Oct 2010 10:53
Ford Mondeo 1999 auto petrol - Fuse keeps blowing - dixharp

hi
the 7.5amp fuse that controls the dash lights keeps blowing. my garage diagnosed a possibly faulty alternator so i spent £212 having it replaced but the fuse blew immediately again. Tried putting 10amp fuse in but thagt blew too. does anyody know what could be causing this? thanks

Reply | Report as offensive | Link
Sun 31 Oct 2010 13:43
Ford Mondeo 1999 auto petrol - Fuse keeps blowing - Collos25

Go back to the garage and get your money back because they do not know what they are talking about.How did they arrive at a faulty alternator did they not do any checks if it blows a 10amp fuse (as opposed to melting it) on the dash lights you have one serious short to earth on that circuit.Also if you keep putting overated fuses in the circuit you are liable to cause all sorts of damage.

Reply | Report as offensive | Link
Sun 31 Oct 2010 17:42
Ford Mondeo 1999 auto petrol - Fuse keeps blowing - dixharp

well they said they checked for shorts and couldnbt find any. but a voltmter across the alternator showed it was peaking at 15v instead of 12v. this was their only suggestion of a remedy, could not guarantee it was a fix, my call whether they try it or not. i could see no alternatvie so said yes.. so it;s down to me. don't know where to turn now re trracing short circuit... go to autoelectircal specialist i guess.. tks for yr respose

Reply | Report as offensive | Link
Sun 31 Oct 2010 16:02
Ford Mondeo 1999 auto petrol - Fuse keeps blowing - Avant

Moved to Technical.

Reply | Report as offensive | Link
Sun 31 Oct 2010 17:49
Ford Mondeo 1999 auto petrol - Fuse keeps blowing - elekie&a/c doctor

When you say dash lights,do you mean the green illumination of the instruments or the warning lights that come on with ignition on.ie battery/oil handbrake?

Reply | Report as offensive | Link
Sun 31 Oct 2010 18:06
Ford Mondeo 1999 auto petrol - Fuse keeps blowing - Collos25

Alternators run up to 14.4 volts so their measurement of around 15 volts was probably ok,fuses do not normally blow through over voltage they tend to melt.I think you need it looking at buy someone like "elekie&a/c doctor".

Reply | Report as offensive | Link