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Fuel pump circuit fix

Discussion in 'Mondial' started by godabitibi, Oct 12, 2013.

  1. godabitibi

    godabitibi F1 Veteran

    Jan 11, 2012
    5,999
    La Sarre, Quebec, Ca
    Full Name:
    Claude Laforest
    #1 godabitibi, Oct 12, 2013
    Last edited by a moderator: Sep 7, 2017
    Hi guys, since my Sera had the fuel pump circuit burnt terminal syndrome I was thinking of an easy way to fix it permanantly since I know my car previously had that same problem and the connector and terminals were replaced with new ones (the old ones were with the service records) and the problem was only moved to a later date again.

    The problem is the weak terminal on connector W that is too flimsy to stand the amperage of the circuit and with time it heat up and eventually burn.

    The simpliest and cheapest solution I thought of is to replace that connection with a stronger one for the circuit by adding a relay.

    The fuse and the other part of the circuit seem to hold up well to the load since they do not overheat from what I see. I hope removing the load on the weak connector will not move the load to another weak unknown connection of the circuit like the circuit bord supplying the fuse terminal. So here is the cheap solution I have in mind.

    Remove the fuse of the circuit and place a remote fuse holder connected in the old fuse connectors with flat male connectors to be able to connect the power for the added relay to pin 30. That eliminates the need to go to the battery with another protected wire making the fix much more simple. (If you prefer to be more safe run a new protected wire(fused) from the battery to pin 30).

    Then cut the Brown wires from the weak connector (keep a sufficient lenght of the small one on the connector to solder a new one to the relay) and wire them to the pin 87 of the added relay to the pump.

    From the weak connector the wire would only feed the pin 85 for the relay solenoid that normally only need about 200mA. This way the connector would never heat. The pin 86 would go to a good ground.

    Let me know your thinking about this fix.

    I know this only fix the fuel pump circuit and in no way is as good as Mr Helm fuse board upgrade solution. So if you want a complete fuse box permanent fix you better buy SRI kit.
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  2. RichardAguinsky

    RichardAguinsky Formula Junior

    Nov 12, 2007
    477
    Palo Alto, Californi
    Full Name:
    Richard Aguinsky
    I like your approach. You are using the original relay to power the coil of the outside relay. You could also do this to the ac relay, next to it, as it also gets hot. Though now you have to mount the components outside.

    The problem is pin 7 as shown in your schematic, it gets hot as it was not meant to carry so much current. I was planning in removing the pin from the white block to stop the heat and add an external connector in parallel. The external connector would be soldered directly to the socket of the fuel relay from underneath with thick wires. If I need to disconnect the white connector, I would also need to disconnect the new external connector.

    I didn't see any two terminal connector for about 20A at Fry's or OReily's that is easy to assemble and solder.
     
  3. dfranzen

    dfranzen Formula 3
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    Aug 31, 2013
    1,529
    Jacksonville , FL
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    Don Franzen
    With all the recent talk about the wiring I got around to checking my white connector. I started to panic as I noticed that it was pretty burnt looking

    here is what was done previously to fix

    the two brown wires were crimped to a single "jumper" wire (14/16ga?),that wire had a female receptacle that fits exactly to the fuse box spade

    NOTE the wire was run through the "white" connector before the ends were crimped so when the connector is placed into its fuse box receptacle it all looks original

    ill post some pics of this
     
  4. godabitibi

    godabitibi F1 Veteran

    Jan 11, 2012
    5,999
    La Sarre, Quebec, Ca
    Full Name:
    Claude Laforest
    What year is your car? I think there are different fuse boxes. On my car the pin in the box are very small and I would not feel better with a female connector. I like the fact that with my mod the connector only carry .002 amps.
     
  5. porphy

    porphy Formula 3

    Dec 9, 2009
    1,171
    LouisvilleKY/Switzld
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    Randall Gatz
    I think I have the same mod. Please post pics. Thanks much.
     
  6. dfranzen

    dfranzen Formula 3
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    Aug 31, 2013
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    #6 dfranzen, Oct 14, 2013
    Last edited by a moderator: Sep 7, 2017
    This is an 88 3.2 modification

    As an electronic engineer this looks like the correct way to "fix" the white connector contacts, by "splicing" jumper wires directly with a jumper wire receptacle to the fuse box spade

    the white connector is not a "fuse" there is a fuse already is series with the connection this only by-passes the "white connector" weak link


    pic "Splice" shows the two browns spliced into the single red jumper, note the larger gauge red wire

    pics connect1 and connect2 shows the receptacle into the fuse block spade

    This work was performed by the one of the top "wrenches" in Orange County , CA

    he forgot he did this but recommends it on 4 of the white connections

    hope this helps
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  7. godabitibi

    godabitibi F1 Veteran

    Jan 11, 2012
    5,999
    La Sarre, Quebec, Ca
    Full Name:
    Claude Laforest
    Don for how long this had been like this? If there is no evidence of heat this is the easiest way to fix it. Is it possible for you to show the connector he used.
     
  8. dfranzen

    dfranzen Formula 3
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    Aug 31, 2013
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    #8 dfranzen, Oct 15, 2013
    Last edited by a moderator: Sep 7, 2017
    Claude,
    From the records that I was given the car was towed in with no start condition 14 years ago about 10K miles. I can only assume that this was the fix then. The reciept is from the same wrench that has done the work for the past 15 years.

    By the way it appears that the jumper wire is 12 ga from the splice inscription

    the spade fits perfectly into the fuse box receptacle
    hope this helps

    Don
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  9. dfranzen

    dfranzen Formula 3
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  10. godabitibi

    godabitibi F1 Veteran

    Jan 11, 2012
    5,999
    La Sarre, Quebec, Ca
    Full Name:
    Claude Laforest
    how do I tie post togheter?
     
  11. dfranzen

    dfranzen Formula 3
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    Aug 31, 2013
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    Jacksonville , FL
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    Don Franzen
    #11 dfranzen, Oct 16, 2013
    Last edited by a moderator: Sep 7, 2017
    pic "Splice" shows the two browns spliced into the single red jumper, note the larger gauge red wire

    Claude does that answer your question?
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  12. godabitibi

    godabitibi F1 Veteran

    Jan 11, 2012
    5,999
    La Sarre, Quebec, Ca
    Full Name:
    Claude Laforest
    Yes thanks!
     
  13. dfranzen

    dfranzen Formula 3
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    Aug 31, 2013
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    Jacksonville , FL
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    Don Franzen
    Glad I could help.

    Hope you are safely back on the road soon!
     

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