PATS red light on
JC - 20/6/17 at 03:28 PM
Hi all,
The continued saga of my electrical woes......
After my last post, I discovered a loose relay. When I gently pushed it, it made, fuel pump ran and engine cranked with spark.
Having touched nothing, the gremlins have been in....
Now, with ignition key at position 2 (where pump used to run) the PATS light comes on constantly. Engine still cranks, with spark.....
Confusingly 12v seems to arrive at the fuel pump and the pump earth is intact but I tried a test lamp in place of the pump and it didn't light!!!
The pump has been checked by applying V directly!
Looks to me like PATS is putting its oar in!!!!
I disconnected the key transponder and the light starts flashing and the car won't crank!!!
HELP!!!!! (again....) 
tims31 - 20/6/17 at 04:03 PM
quote:
Originally posted by JC
Hi all,
The continued saga of my electrical woes......
After my last post, I discovered a loose relay. When I gently pushed it, it made, fuel pump ran and engine cranked with spark.
Having touched nothing, the gremlins have been in....
Now, with ignition key at position 2 (where pump used to run) the PATS light comes on constantly. Engine still cranks, with spark.....
Confusingly 12v seems to arrive at the fuel pump and the pump earth is intact but I tried a test lamp in place of the pump and it didn't light!!!
The pump has been checked by applying V directly!
Looks to me like PATS is putting its oar in!!!!
I disconnected the key transponder and the light starts flashing and the car won't crank!!!
HELP!!!!! (again....)
On mine, the PATS LED comes on and stays on when the ign turned to pos 2, pump runs then stops once primed. Flashing normally indicates a fault like
removing the transponder...I think the LED Should remain lit and go out once engine has started.
I missed the original psot, What engine /ECU is it. What loom are you using?
[Edited on 20/6/17 by tims31]
JC - 20/6/17 at 05:20 PM
Sorry, should have said!!
1.25 Zetec SE with donor loom and ECU from 1996 Fiesta. ECU code SLIM as I recall.
tims31 - 21/6/17 at 10:33 AM
Have a look at the codes here and it should give you an idea of the fault by the number of times it flashes
Here
This may also be of use
JC - 21/6/17 at 09:11 PM
OK.....
So, sat on hands and timed a minute.....
Constant red light turned into what appears to be 2:1 flashes - less than 3 keys programmed.
According to this the engine should still start so not sure why fuel pump isn't running. Could it be a spurious signal from fuel pressure
sensor? (If there is one)...
RichN - 22/6/17 at 01:53 PM
This is the exact setup that I have used on my Sylva Riot.
On mine, when you turn the key to Position 2, the fuel pump runs and then stops to prime the system. The PATS LED is on and not flashing at this
point.
Does this happen on yours? If not perhaps it's worth re-checking the fuses and power to the fuel pump.
JC - 22/6/17 at 02:12 PM
Hi,
Its weird - if I check at the plug that goes into the fuel pump I have 12v, at least momentarily, and a good earth, so I guess the fuse is ok. The
pump runs when connected straight to a power source and I seem to have a good connection on the multiple and out to the pump, it just doesn't
run!
It did run a few weeks ago and perform exactly as advertised....
Time to re-check fuses and everything else methinks!!!
tims31 - 22/6/17 at 02:30 PM
quote:
Originally posted by JC
Hi,
Its weird - if I check at the plug that goes into the fuel pump I have 12v, at least momentarily, and a good earth, so I guess the fuse is ok. The
pump runs when connected straight to a power source and I seem to have a good connection on the multiple and out to the pump, it just doesn't
run!
It did run a few weeks ago and perform exactly as advertised....
Time to re-check fuses and everything else methinks!!!
As Rich says above, the pump should run when you first turn the key to prime the system and then either appears to stop or can not be heard running
once the system is primed. Then once you turn to start it should then run. This is how mine works at least. The Fuel regulator does not have any
electrical connection on mine.
Does yours have the pump monitor line feedback to the ECU, was Pin 40 on my Blacktop ECU
[Edited on 22/6/17 by tims31]
MikeRJ - 22/6/17 at 04:04 PM
quote:
Originally posted by JC
Hi,
Its weird - if I check at the plug that goes into the fuel pump I have 12v, at least momentarily, and a good earth, so I guess the fuse is ok.
Are you testing by back probing the connector, or by pulling the connector and sticking the meter probes in the front? If the latter then you can
still measure 12v even if there is a high resistance in the fuel pump circuit, since a meter draws almost no current. The circuit needs to be loaded
when you measure it, either with the pump or a test lamp.
RichN - 22/6/17 at 07:52 PM
If you have kept the main Ford fuse box, I would check:
F35 for the fuel pump
F36 for the Engine Management (this is a 60a yellow fuse)
and Relay III which controls the fuel pump.
Hope you get it running soon.
JC - 23/6/17 at 08:39 AM
Thanks Rich - hopefully get a chance to check those later...
JC - 23/6/17 at 04:23 PM
OK.....removed and checked both fuses - both fine, but no voltage at pump.
Then remembered that the last thing I was doing yesterday was parting about with the fuel inertia shut off. Reset that - and got 12v back at the
plug. Connected pump and connected voltmeter to pump terminals - it ran!!!!!! Removed voltmeter. It still runs!!!!
I have changed nothing. It now works. I hate electrics!!!!!!
Thanks for all the helpful advice once again guys - just need to connect a few lines and we will have start up...I hope!
big_wasa - 23/6/17 at 05:24 PM
It's going to be a loose or bad connection with a power supply or earth.
You really need to go through it one circuit at a time or you will loose interest.