[DML] Re: Fuses

["Walter" <Whalt@xxxx>]

In response to John Hervey's post,

The current feeding the radiator fans in the Delorean are NOT fused through
the fuse block! Why are you confusing us?

If all the devices feeding through the 20 amp fuses in the Delorean are
running properly, then putting a 15 amp fuse in place of any of these will
cause the fuse block to run ever so slightly hotter. This is only because
the smaller fuse element will have more restriction to current flow
producing more heat.

This is a difficult concept to get across to people without an electronics
background, but I'll give it a shot: The reason why there are melt-downs in
the Delorean fuse block is because the connections to the fuses are too
small. This has nothing to do with the current ratings of the fuses. A
different style of fuse holder is a good tempory fix and creates job
security for your mechanic, but replacing the fuse holder with one that
takes a heaveir duty style of fuse solves this problem.

Good engineering practices suggest fusing circuits at 75 to 80% of the
normal running load. For example, if you have a radiator fan that draws the
14 amps that you measured, then 75 to 80% capacity of a 20 amp fuse would be
15 to 16 amps -- a tad much maybe, but still a good choice. For a 15 amp
fuse, 75 to 80% of that would be 11.25 to 12 amps, which is not enough You
need to take into consideration that the fans draw a surge when they come
on.

HOWEVER, there are no fuses protecting the radiator fans! They use an
under-rated 35 amp thermal switch which is routinely replaced with a 40 amp
version recommended by most of the major Delorean suppliers. If you do
anything to starve the radiator fans for current, then you will cause them
to run hotter.

Walt Tampa, FL

-----Original Message-----
From: John Hervey <dherv10@xxxx>
Subject: [DML] Re: Fuses


>fuse. I case of the cooling fans in the De Lorean, I see 20amp fuses
>all the time and thats to much. If the motors are in good running
>order then a 15Amp fuse will work just fine. It will handle the
>inrush current and run normally at room or car temp. If 20 amp fuses
>are used, then you stand a chance of burning up wires in the motor
>and creating more damage due to the overheating wires and melting
>wires in the motor circut.