electrical problems relating to fuel pump

[Joel Pash <joelpash@xxxx>]

Sorry for the long email, but maybe someone can help
me. Several months ago my Delorean started to blow
the RPM relay fuse (when starting the car) resulting
in not starting. At first I thought it was the alarm
that was causing the problem (the previous owner had
an alarm installed - not very well) so I disconnected
the alarm. The problem kept happening, so I drove
around with spare fuses as a temporary solution. 

Last week I was driving and the car died in the middle
of the street. This was the first time that had
happened - it usually would blow the fuse when I tried
to start only. Sure enough the fuse was blown, and
the holder was all melted. So I bypassed the fuse by
cutting it out and connecting the two wires. I drove
the car home no problem.

I thought the problem may be the fuel pump drawing too
much current, so I replaced it right away. When I
tried to start the car, it didn't start again.

Here is what I know for sure:

a) If I open up the RPM relay fuse and force the
solenoid inside to contact, the fuel pump runs. The
solenoid does not move however, when I turn the key
(it is obviously supposed to.) This relay is working
because I have two of them and one of them is brand
new.

b) I thought that I had traced the problem back to the
main fuel relay being blown. So I replaced that. I
tried to start the car but I noticed the main fuel
replay fuse (fuse #1) was blown. So I replaced that. 
The car started and ran for about 5 minutes, then
died.

c) The fuses in the fuse box are all higher amp fuses
than they are supposed to be. I just noticed this
yesterday when reading the workshop manual so I
replaced them.

d) Most of the relays in the car are Bosch, so I
understand this means they have been updated at some
time.

I have a few thoughts. First of all, I need to
determine what is causing a short in my electical
system. I originally thought it was the fuel pump but
it is obviously not that because that has been
replaced. Perhaps it is the fuel filter?

Second, why were all the fuses wrong. Perhaps the
previous owner replced 20 amp fuses with 30 amp fuses,
10s with 20s, etc, to stop them from blowing. Perhaps
this is why relays may be getting fried.

The thing that concerns me is that before I was just
blowing the RPM relay fuse. Now I am not even blowing
fuses, just other stuff. And the car doesn't run. 
Before I changed the fuel pump it did. (I also tried
putting back the old fuel pump, but the same problem.)

I have gone through all of the wires with a volt meter
and I can't find any wires that are not conducting. 
Maybe I am doing it wrong? Does anyone have any
ideas?

Thanks very much.

Joel


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