Re: electrical problems relating to fuel pump

["John Hervey" <dherv10@xxxx>]

Joel, 
I think what your talking about is the Main Relay which supplies 
voltage to energize the coil of the RPM relay when the car is being 
started. Then the contacts close on the RPM relay to supply voltage 
to fuel pump like DMC JOE said through the brown to white/purple. If 
you know how, take out the RPM relay, remove the cover and with a 400 
grit emery cloth strip about 1/8" by 2", very lightly Just two or 
three pases of the emery cloth over the contacts will remove any 
electrical corrosion build up which can cause the low voltage problem 
to the pump.
If all this doesn't work, then again you have a problem somewhere 
else. But there really is no where else. 
If you need a relay to operate the fuel pump independently of the 
RPM relay, I can fix you one up for that.It's a higher current relay 
cost $15.00 + postage.

John Hervey


--- In dmcnews@xxxxxxxxxxx, joelpash@xxxx wrote:
> Placing the jumper between the two wires causes the fuel pump to 
> run. The car will still not start however when this jumper is 
> connected. I replaced the main fuel relay and that is not the 
> problem either because the car will still not start. There is a 
> white and purple wire that goes from the fuel pump to the RPM relay 
> and this is only showing about 4 volts with a volt meter when 
tested 
> between the connection to the RPM relay and the stainless steel on 
> the car. When I try to start the car it moves up to about 6-7 
> volts. I am not sure what the significance of this is because I 
> think it should only be 12 volts if the relay closes, but it is 
just 
> an observation. This did lead me to think however that it is 
> possible that the wire betwen the relay and the fuel pump is 
> damaged. Evidence supporting this theory would be that it was the 
> only wire I touched when I changed the fuel pump (because I needed 
to 
> disconnect it.) What doesn't make sense however is that the car 
> started without me touching that wire, and then subsequently died. 
> But it only did this once.
> 
> I am thinking about getting an OHM meter and testing the 
white/purple 
> wire. What else should I look at now?
> 
> Thanks again.
> 
> 
> --- In dmcnews@xxxxxxxxxxx, "DMC Joe" <dmcjoe@xxxx> wrote:
> > Joel,
> > 
> > First; replace all of the fuses with the specified rating per the 
> workshop and owners manual.
> > I suspect that you have replaced the fuel pump fuse # 7 with an 
in-
> line type replacement. It is also probable that the previous owner 
> has done some re-wiring in the fuel pump circuit.
> > 
> > You can easily temporarily by-pass the RPM relay and force the 
fuel 
> pump to run by placing a suitable jumper between the brown and 
> white/purple wires at the RPM relay connector. The relay does not 
> have to be installed to conduct this test. 
> > 
> > Try this test and let me know the result. 
> > 
> > "We're here to help you"
> > 
> > DMC Help / De Lorean Services / <dmchelp@xxxx>
> > Web Site: <www.deloreanservices.com>