Click here to sign up  Click here to go to the galleries  Click here to go to the code of conduct  Click here to go to the video page  Click here to go to the SW Meets page
Page 1 of 2 1 2 LastLast
Results 1 to 10 of 16

Thread: Fuel pump and ignition circuit fuse blowing on mu Cabrio. Help!

  1. #1 Fuel pump and ignition circuit fuse blowing on mu Cabrio. Help! 
    club member Club Member
    Join Date
    Sep 2012
    Posts
    13
    Fuel pump and ignition circuit blowing fuse.

    Hi, can any one help with ideas on common causes for this problen.
    My cabrio has developed an intermittent fault causing the fuse to blow on the ignition and fuel pump combined circuit. V inconvenient as it happened on the pass of glencoe road in pouring rain resulting in the car needing recovery to a garage in Fort William. The fault resolved itself after 4 blown fuses and the cause was not found by the local garage. All of the other car systems worked normally.
    It happened again 200 miles later on the Isle of bute and resolved after another 6 blown fuses during fault finding. The Island's mechanic again could not find the fault and it finally resolved again long enough for us to drive onto the ferry back to the mainland and load the marlin onto a recovery truck to take us home to leeds. A bit of a saga!

    The cabrio has mechanicals from a 1993 ford sierra 2.0 DOHC EFI including the fuel pump and ecu.
    The wiring loom is from Premier wiring systems. There is no fuel pump cut off or relay.
    there is no damage to the loom on the visible parts and no evidence of burnt wires.

    Current thoughts are;
    1) Is there an intermittent fault in the fuel pump causing the short. Next time it happens I will see if the fuse still blows with the pump disconnected
    2) Is there a fault in the ignition circuit, if so where and how do I isolate it to test it. The PWS loom instructions do not help for this.

    Does anyone have other Ideas, similar experiences or knowledge about the commenest causes of this problem?

    Here is hoping
    Best wishes to all
    Peter
    Reply With Quote  
     

  2. #2 Re: Fuel pump and ignition circuit fuse blowing on mu Cabrio. Help! 
    club member Club Member
    Join Date
    Nov 2011
    Posts
    738
    Was it raining when it blew on the Isle of Bute or dry?
    Reply With Quote  
     

  3. #3 Re: Fuel pump and ignition circuit fuse blowing on mu Cabrio. Help! 
    club member Club Member
    Join Date
    Sep 2012
    Posts
    13
    raining both times.
    Reply With Quote  
     

  4. #4 Re: Fuel pump and ignition circuit fuse blowing on mu Cabrio. Help! 
    club member Club Member
    Join Date
    Nov 2011
    Location
    Bakewell Derbyshire
    Posts
    288
    Damp near the fuel pump relay?
    Reply With Quote  
     

  5. #5 Re: Fuel pump and ignition circuit fuse blowing on mu Cabrio. Help! 
    frequent forum contributor Club Member greyV8pete's Avatar
    Join Date
    Nov 2011
    Location
    Exeter
    Posts
    1,311
    Anything else on the same fuse? Wipers, screenwash pump etc? Did you switch something else on when the pump stopped, or did it just stop working?I would disconnect each component supplied by that fuse, at the component itself, then switch on and wiggle all wiring. Then reconnect each component in turn and wiggle the wiring each time, in case something live is touching the chassis. Is the fuse the correct rating? Is it the correct type? If supplying a motor I would expect to see a slow blow type fuse. Have you recently fitted or serviced anything else electrical recently? Even new parts can be faulty! Peter.
    Reply With Quote  
     

  6. #6 Re: Fuel pump and ignition circuit fuse blowing on mu Cabrio. Help! 
    Moderator Club Member
    Join Date
    Nov 2011
    Location
    Derby
    Posts
    1,596
    Did you notice if the pump was warm/hot to touch?
    Reply With Quote  
     

  7. #7 Re: Fuel pump and ignition circuit fuse blowing on mu Cabrio. Help! 
    club member Club Member
    Join Date
    Sep 2012
    Posts
    13
    Thanks for your replies.
    I have not found a fuel relay yet but assume there must be one as the original sierra wiring diagram shows one between the ecu and the pump and it seems unlikely that the ecu will put out enough current to work the pump. I will keep looking.

    re; other items on the same circuit. the fuse still blew after I had disconnected all connections to the steering column switches ie. lights, indicators, horn, wipers, screen washer.

    re was the pump hot. it is an in tank pump so you can not touch it. Happily there was no smell of boiling fuel!

    re did it happen when I switched something else on or off? No I was not switching any other control.

    re fuse. normal 15 amp fuse which had worked without problems for 10 years and 30000 miles

    thanks for yor thoughts.
    looking forwards to hearing any other Ideas which members have
    Peter
    Reply With Quote  
     

  8. #8 Re: Fuel pump and ignition circuit fuse blowing on mu Cabrio. Help! 
    club member Club Member jon_cox's Avatar
    Join Date
    Nov 2011
    Posts
    531
    Hi Peter
    All cars fitted with an electronic fuel pump, in theory, should also have an inertia cut off switch in the case of an accident. It basically has a ball bearing in it that moves under heavy deceleration due to an impact, that cuts off electrical power to the pump. A safety feature in case the fuel line is compromised so you don't pump gallons of fuel all over the place creating a significant fire hazard.
    I do not know where it is positioned in the Cabrio (or if there is one at all ) but this could be the cause of the problem if it has corroded connectors.
    It should look like this:

    FORD-GALAXY-1998-FUEL-CUT-OFF-SWITCH-F2AB-9341-AA.jpg
    Mk2 SWB Marina Roadster with a 1800 Fiat Twin Cam engine and 5 speed Abarth gearbox built in 1987
    - I have no idea what I am talking about........ but my advice is always free! -
    Reply With Quote  
     

  9. #9 Re: Fuel pump and ignition circuit fuse blowing on mu Cabrio. Help! 
    Moderator Club Member
    Join Date
    Nov 2011
    Location
    Derby
    Posts
    1,596
    Apologies, I missed the fact that you stated pump was from the donor Sierra.
    Reply With Quote  
     

  10. #10 Re: Fuel pump and ignition circuit fuse blowing on mu Cabrio. Help! 
    frequent forum contributor Club Member greyV8pete's Avatar
    Join Date
    Nov 2011
    Location
    Exeter
    Posts
    1,311
    Jon_cox’s comment above reminds me that my son had the same problem with his classic Range Rover and the cut out switch on those was a known cause of the random cutting out problem on those vehicles. As I have the L/R Disco V8 engine in my Hunter I have the same switch which looks like the photo below. On my Hunter it is mounted in the engine compartment on the nearside bulkhead and next to the 100A fusible link. The round end is mounted facing upwards. It has a flexible rubber cover which you press in to reset it. Peter.
    E217A361-AAE4-444C-A010-1A749CA5ACBB.jpeg
    Reply With Quote  
     

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •