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Thread: in Need of your thoughts and advice

  1. #1
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    in Need of your thoughts and advice

    So my Roadster has, for the first time, started acting funny on me.
    Okay, maybe not the first time, but the first in a while.
    Anyway, last year, my horn suddenly came on while i was driving and wouldn't shut off. The only way to shut it off was to take turn off the car or disconnect the horn altogether.
    I did the later.

    This year, the problem with the horn not only continues, I noticed my fan would stay on even after removing the key from the ignition.
    Upon further inspection I realized the car would stay in the on position (you know when you turn the key once which primes the car before actually starting the engine) even when I would remove the key completely.
    The only way to shut it down was to disconnect the battery.
    What's going on?
    Any thoughts?
    Has anyone else had this issue?
    Is it an ignition switch issue?
    A fuse box or electrical wiring issue?
    I'd love to get you all's feedback.

    Thanks in advance.

  2. #2
    Senior Member turbonut48's Avatar
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    Sounds like the ignition switch, and/or a relay.
    The Nut Tom

  3. #3
    Senior Member edwardb's Avatar
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    More details please. Ron Francis harness? Fan controlled by Ron Francis harness or something else? Standard Factory Five ignition switch?

    Agreed if standard RF harness and RF harness controlled fan, ignition switch doesn't control those. If turning the ignition off shuts off a stuck horn, maybe something isn't wired right. Key coming out of the ignition with it still in the on position, if that's really what's happening, would be a defective switch.
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  4. #4
    #9160 BB767's Avatar
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    The horn and fan wiring have a lot in common; the CB’s are next to each other, as are the relays. They are both powered by the direct battery bus which should not be associated with the ignition switch. The wires for both circuits run through the front harness. I would start by checking this area in the fuse panel for contamination (metal shavings) or loose or shorted wires. As for the ignition switch, what stay’s on that shouldn’t? Lights (stop, tail, turn, high, low), fuel pump, heater, gauges (any or all)? Check each item individually for clues to what is shorted.
    MK4 - complete kit - Blueprint 427W - Holly Sniper EFI - TKO 600 .64 - 3.55 3 link - 17" Halibrands

  5. #5
    Senior Member Itchief's Avatar
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    You may want to check for a water leak around the drivers windshield support a water leak there will go onto the back of the fuse/relay panel and causing the relays to fail.

    Don’t ask how I know this will happen

    Good luck

    Rick
    #8475 Complete Kit Delivered Nov 2014, started Nov 2015, Street Legal Apr 2016, Paint and Interior Completed Aug 2017, 390 BBF, March accessory kit, MSD Atomic EFI and Ready to run, TKO 500 with MidShift kit, hooker headers, 3 link, track lock with 3.55, sway bars, power steering, wipers, heater

  6. #6
    Senior Member Avalanche325's Avatar
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    Quote Originally Posted by Itchief View Post
    You may want to check for a water leak around the drivers windshield support a water leak there will go onto the back of the fuse/relay panel and causing the relays to fail.

    Don’t ask how I know this will happen

    Good luck

    Rick
    Exactly what I was thinking. The windshield pillar is a funnel right to the fuse box. I went through several flashers before I finally got mine to seal. You have to get under there, load your finger up with silicone and smear it around.

  7. #7
    Senior Member AC Bill's Avatar
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    Sounds like a bad ignition switch, as far as staying in the on position. There seemed to be an issue with quite a few FFR supplied ones several years back. Maybe it just took awhile for yours to go sour.
    Does the cooling fan run, even when the engine is cold?

    The horn switch is something I would look at, as far as that problem.

  8. #8
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    My deepest apologies for not replying sooner.
    I, unfortunately didn't have access to the internet (traveling)
    Please know I never take this community's support for granted.

  9. #9
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    Quote Originally Posted by edwardb View Post
    More details please. Ron Francis harness? Fan controlled by Ron Francis harness or something else? Standard Factory Five ignition switch?

    Agreed if standard RF harness and RF harness controlled fan, ignition switch doesn't control those. If turning the ignition off shuts off a stuck horn, maybe something isn't wired right. Key coming out of the ignition with it still in the on position, if that's really what's happening, would be a defective switch.
    It's FF standard everything on a MK3. I agree, the switch doesn't seem to control the horn but it does control the fan. When I turn the switch to the on position the fan will often come on (if I've been driving it). I completely removed the key from the ignition switch and all my interior lights stayed on, including the fan. Keep in mind this is a new problem, so while it may be a deterioration issue or perhaps a cut wire issue, it's not that the wiring was installed wrong.
    Sounds like I may be having two issues. Ignition switch and some kind or wiring or fuse issue.
    Thanks so much for your reply.
    It may be

  10. #10
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    Quote Originally Posted by BB767 View Post
    The horn and fan wiring have a lot in common; the CB’s are next to each other, as are the relays. They are both powered by the direct battery bus which should not be associated with the ignition switch. The wires for both circuits run through the front harness. I would start by checking this area in the fuse panel for contamination (metal shavings) or loose or shorted wires. As for the ignition switch, what stay’s on that shouldn’t? Lights (stop, tail, turn, high, low), fuel pump, heater, gauges (any or all)? Check each item individually for clues to what is shorted.

    Unfortunately the wiring is the one area in my car I completely left to someone else (during the initial build). Should I just change the fuse box (and all the fuses) as well as the ignition switch? And check for any water leak issue?
    For the ignition switch, all my gauge lights stay on, as well as the fan.
    turning and removing the key had no effect.

  11. #11
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    Quote Originally Posted by Itchief View Post
    You may want to check for a water leak around the drivers windshield support a water leak there will go onto the back of the fuse/relay panel and causing the relays to fail.

    Don’t ask how I know this will happen

    Good luck

    Rick
    Intersting, I'm now wondering if the problems didn't start after I washed the car. So what did you do. Is it a matter or replacing all the fuses/relays or completely changing the panel?

  12. #12
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    Quote Originally Posted by AC Bill View Post
    Sounds like a bad ignition switch, as far as staying in the on position. There seemed to be an issue with quite a few FFR supplied ones several years back. Maybe it just took awhile for yours to go sour.
    Does the cooling fan run, even when the engine is cold?

    The horn switch is something I would look at, as far as that problem.
    I don't think it's a horn switch issue as the horn came on completely by itself out of the blue. It's not like I pressed the horn and it stayed on. It just blared as I was driving.
    The cooling fan stays on with the engine relatively cold. Hadn't driven it but had turned the engine on to warm the car up.
    Like I said in a post above, I may be having two separate issues at the same time.
    Appreciate the thoughts and responses. I now have a better idea of what to check.

  13. #13
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    btw, just turned her back on and switch seems to be ok... for now.

  14. #14
    Senior Member Avalanche325's Avatar
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    As far as the horn and fan go. Most times, things are turned on and off by making and breaking the ground. A short on the ground side of the control circuit can turn things on.

    The other part sounds like the ignition switch. It is never fun if you are dealing with multiple faults.

  15. #15
    Senior Member Itchief's Avatar
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    Your fuses should be fine there should be three relays one for the horn, fan and fuel pump you can pull one of the relays and go to any of the usual suspects advance auto auto zone etc and get replacements they are only a few bucks each

    After my fuel pump stopped working because of the water leak I keep a spare relay in the car

    Rick
    #8475 Complete Kit Delivered Nov 2014, started Nov 2015, Street Legal Apr 2016, Paint and Interior Completed Aug 2017, 390 BBF, March accessory kit, MSD Atomic EFI and Ready to run, TKO 500 with MidShift kit, hooker headers, 3 link, track lock with 3.55, sway bars, power steering, wipers, heater

  16. #16
    Member Kpt112's Avatar
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    Last year I had a similar problem with the car's turn signals. I tore the whole dash apart then found out it was a bad relay. Try the simple stuff first like fuses and relays, they are cheap and easy to replace. I also had a switch issue with my headlight assembly. Tore the dash apart on that and it turned out to be bad switch. The electric components are not the highest quality in my opinion. The horn is especially cheaply made just some plastics parts and a spring. That is why it is priced at $4.00

  17. #17
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    Thanks Gang, very, very helpful hints.
    Will follow for sure and let you all know.

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