I do not have a test light, but I do have a multimeter. I was able to
disconnect one (broke one side of the hold down because the plastic is very
brittle). I put a jumper wire across the two terminals, put an alligator
clip lead from there to the positive side of my multimeter, then grounded
the other side to good ground. Cranked the engine. The meter went to 12
volts. Meaning, I am getting electric flow to the injectors.
I have no fuel gauge and can't find the connector on the fuel rail anyway.
Take Care, Sharon
<sigh> What you did was to short the injector circuit, not a
very good thing to do (may have smoked the injector drivers).
Even installed the way I described, a mechanical volt meter would
probably not be able to respond to the injector signal fast
enough. I had no doubt that you had voltage supplying the
injectors, you proved that when you checked voltage to the red
wire going to the fuel pump relay since that is the exact same
circuit that the EEC relay switches on to power up all the
various driven devices in the system.
What needed varification was whether the injectors were being
signaled -by- the engine computer, the easiest down and dirty way
to do that is to substitute a light bulb in place of the injector.
If you'd have mentioned that you didn't have a test light, you
could have been directed to scrounging one of the vehicles side
marker lights to use as a substitute. Since I know for a fact
that a side marker bulb only draws 1/4 amp, this would have
facilitated a safe test method and it would have only been at the
expense of an (temporarily)inoperative side marker.
If you don't have a tool to do a test with or are unclear on how
we're describing to hook it up, please, please, please, stop,
post back for clarification or for a way to fabricate or
substitute. You can't begin to imagine how easily the integrated
circuits can be fried inside the engine computer by performing a
test wrong or by substituting a different piece of test equipment.
LOL! I give you and Thomas a lot of credit for sticking this one out as long
as you have, but I think you may have finally met your match. Good luck...
You're gonna need it. Ford builds a pretty bulletproof PCM, I guess we'll
find out how good they protected the injector drivers... or not.
She may not have but it wasn't for a lack of trying. I see at one point she
jumped the tan/lt green wire to power also. I've seen this kind of thing all
too many times. Someone who is trying to save a buck by doing car repairs
themselves winds up bringing it in 'cause they finally gave up. Now they
have not only the original problem but several others caused by the work
they've tried to do. Usually not a good deal for them.
??? A voltmeter has high resistance. The higher the better, in fact.
Suppose it was 1Mohm (it's probably more than that). The maximum
voltage it could be seeing is about 14V. So Ohm's Law tells us that at
most there could have been 14/1000000A (14 microamps) flowing. Any
semiconductor that couldn't deal with that much leakage current in any
direction has no place in an automobile.
An *AMMETER* has low resistance, yes.
Re-read Sharon's description of *how* she connected the voltmeter
to the injector plug. She didn't describe putting each test lead
to each side of the circuit, she described connecting a jumper
between the two terminals in the injector connector -then-
connected the VOM between the jumper and a ground point.
(about as unorthodox of a method of using a voltmeter as I've
Since you're a fan of Ohms law, solve for how many amps went thru
the injector driver when voltage equals 12.7 and resistance
equals zero (or very near). ;-)
That is normal, when the voltage goes through it's load, i.e., the coil of the
relay and the circuit is grounded, you get 0 volts. If the ground circuit was
open, you would see 12 volts, because it is not a complete circuit. When you see
that the circuit is ok.
By making a ground, you are completing the circuit, energizing the relay, you
will see 0 volts.
Then the relay is bad or wrong. Or the ECM is making ground all the time.
Release the tab that holds the tan wire in the relay socket to make sure the
wire is not broken at the terminal if that is ok put it back in the socket and
one more test. With the relay in it's socket, cut the tan wire in a place you
can splice it back together. Turn the key to run, and see if you have 12
volts. ) 0 volts still means bad or wrong relay. Did you check the resistance
on the relay?
Hi Sharon, Check your e mail @ no.com addres
I've sent you a test instruction for the distributor module. The hotwiring
of the pump is Ok just for test purposes.
It would be a very dangerous way to drive the car in public hotwired in the
fuel pump system.
It is designed this way in case of a crash or fuel line rupture so if the
fuel rails loose pressured the engine stalls,
the pump will stop running. Due to no pulses from the module in the
distributor. So If your module is bad, the car will run
hotwired as you have proved out within these test instructions from everyone
in this forum.
If you drive your car with the fuel pump hotwired and have a crash and fatal
fire, you have it right here in writting
NOT to drive this car in this condition. The switch/breaker in the trunk is
an extra measure of safety.
Replace the module in the distributor. That will solve the problem.
Have you ever noticed the fuel pump keep running when your car stalled..?
I don't think so...
Oh, OK...Just got your mail, and you've got it in the bag now...Just posting
so others know...
OK, I looked at the diagram, at the relay. Using a12 volt test light.
Yellow wire- should have 12 volts all the time, check it while cranking the
If it does have 12 volts all the time, remove the relay. With a jumper wire,
jump from the yellow to the orange wire. The pump should run and the car
should start. Please dont say cranks over if you mean running. Cranks is the
starter cranking the engine, starts is the engine actually running. If it
starts, then say it runs or it starts. Sorry but it can get confusing. Post
back with your results. Maybe if we do this one step at a time we can
firgure it out.
I don't think anyone has suggested that she drive the vehicle
with the fuel pump relay by-passed.
Um, no. The fuel pump relay does what any relay does, it allows
for switching a high load circuit without running heavy gauge
wiring and it allows for control of the fuel pump according to
whether or not the engine is running. The relay in and of itself
has nothing what so ever to do with crash worthyness.
No. If the "module" is bad, the car won't run, plus, there is no
fuel pump running (prime) when the key is first switched on
before the starter is engaged, the fuel pump should at least be
able to prime regardless of whether the 'module" is working
correctly or not.
Oh please, what is it that you think the fuel pump relay can
magically do in the event of a crash?
Finally, a correct statement.
Why? If she jumpers the fuel pump circuit the engine will run.
That proves that there is a PIP signal to the ECM which can
trigger the ignition module -and- pulse the injectors.
IOWs, she'd be wasting $100 on a part that for all mortal
purposes is functioning correctly.
The problem does not manifest itself as a lack of spark or a lack
of injector signal, both of which would be key functions of the
ignition module. She has (for whatever reason) a fuel pump that
will not turn on, even during the prime sequence which is totally
separate from the ignition module.
Have you ever noticed that to energize the fuel pump on any
domestic Ford product, all one needs to do is turn the ignition
switch to the on position; the pump will run for at least two
I didn't think so.
=================================I've got to back up Neal, he's right on the money. It is a power, ground,
and or ECM problem. I would hotwire that pump if I *had to* in a second. But
I would not make a habit of it, it definitely should be fixed. :)
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com ).
After reading all that I have done and following this through from the
beginning. Can you give me some idea of the different auto parts that you
find suspect or that may be causing this?
Thanks and take care, Sharon
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