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Thread: No power to fuel pump relay, why?

  1. #16
    Join Date
    Dec 2012
    Location
    Lincoln, NE
    Posts
    25

    Now that's interesting-Getting weird

    Borrowed a scanner and while trying to get it to read codes turned on switch and the fuel pump charged the lines, so I hit the starter and it starts and runs fine. Apparently computer did not burn out. But who knows how long it will last. So question I have is when key is on engine off for codes scan I have an alarm buzzing, shift light, check gauges light, check engine light, and battery light are all on. I may be dreaming but I didn't think there was an alarm buzzing and that many lights on before all this went down. anybody else check and see if their car buzzs and what lights stay on?

  2. #17
    Join Date
    Jul 2005
    Posts
    389
    Good evening


    Check the passenger side firewall connector to engine harness connector ( the large "square" one). If the connector pin(s) have corrosion, damage and or did not fully connect the buzzing alarm sound and cluster warning lights will come on. I have seen this on a 1989 Thunderbird N/A 3.8 which was converted from MAP to MAF.

  3. #18
    Join Date
    Dec 2012
    Location
    Lincoln, NE
    Posts
    25

    Thanks

    Quote Originally Posted by sam jones View Post
    Good evening


    Check the passenger side firewall connector to engine harness connector ( the large "square" one). If the connector pin(s) have corrosion, damage and or did not fully connect the buzzing alarm sound and cluster warning lights will come on. I have seen this on a 1989 Thunderbird N/A 3.8 which was converted from MAP to MAF.
    Thanks, that fixed the buzzing when I applied dielectric grease to all the terminals. Now it is back to no fuel pump charging the lines. The inconsistency is crazy. Am trying to read codes with scanner but I get a message of 'no communication from module.' Am unfamiliar with this particular 'borrowed' scanner so will probably have to get owner to get me started.

  4. #19
    Join Date
    Dec 2012
    Location
    Lincoln, NE
    Posts
    25

    Computer OK?

    Here is what I think is going on. When I turn the key to on the computer reads 'some things' and if it don't get the right readings it does not ground the fuel pump to charge the system and it does not fire the injectors. Then when I try key on at a later date it reads 'some things' again and this time it gets the right readings and it grounds the fuel pump to charge the lines and it fires the injectors and the car starts. If this is the case what sort of things do I need to look at? When it charges the fuel lines at key on it starts and runs perfect. When it don't charge the fuel line it cranks but it doesn't even try to start. Sounds like gremlins to me.

  5. #20
    Join Date
    Apr 2005
    Location
    Canton, OH
    Posts
    625

    Ignition switch

    Have you checked your ignition switch in the steering column yet? It's known to start separating and cause all kinds of strange issues

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