fuse question

[dave sutton]

My nob has started blowing the big fuse on the rear bulkhead when things get hot from driving vigorously on track (the one just above the bank of four fuses). Now the fuse in place was a 40amp but checking the US build manual it calls it the "rear maxi fuse" and gives its rating as 80amp. My question, which should it be for UK models? I don't want to bang in an 80amp and cause major damage somewhere.

[M.Ako]

My 2004 3R has an 80

[dave sutton]

M.Ako said:

My 2004 3R has an 80

Thanks, I have an idea that a previous owner had a lower rating fuse put in to "protect" the ecu, but I wonder if doing so can cause problems by blowing too soon, although I would have thought that such big currents only arise when starting, normal running shouldn't need that sort of drain?

My problem is now to find out why it blew during normal running.

[andygtt]

your starter bypasses that fuse so you won't have max amp draw on it during starting.... It supposed to be 80amp so I'm not surprised it blows when you are using the fuel pump, coils, injectors and possibly air con at it maximum on track. A single 044 would blow a 15 amp fuse so 40 amp for the entire car is asking a lot.

[dave sutton]

andygtt said:

your starter bypasses that fuse so you won't have max amp draw on it during starting.... It supposed to be 80amp so I'm not surprised it blows when you are using the fuel pump, coils, injectors and possibly air con at it maximum on track. A single 044 would blow a 15 amp fuse so 40 amp for the entire car is asking a lot.

Thanks Andy, a truly definitive answer, 80amp it shall be.