1974 Ranchero brake light Problems.

Discussion in 'General Ranchero Help' started by tbird9140, Dec 28, 2020.

  1. Jeff B

    Jeff B In Maximum Overdrive BRONZE MEMBER

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    When testing fuses, pull the fuse out to test it. That one bit me with a problem with my instrument panel lights and made an easy job harder.
     
  2. handy_andy_cv64

    handy_andy_cv64 In Maximum Overdrive SILVER MEMBER

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    Not to mention the problem that I had, when Babe sat up without the canopy: the cabin got wet inside from water leaks, so the contacts in the fuse box corroded. I had to disconnect the battery, pull all the fuses, and wire brush all the sets of contacts. So make sure that the contacts are all clean also, especially if the car has sat up for any amount of time.
     
  3. tbird9140

    tbird9140 In Second Gear

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    Pretty sure I don't have a fuse problem. I checked all fuses earlier with key on and got power most everywhere. Also believe I read flasher is on circuit with turn signal lights or some other. As I now have all exterior and interior lights and everything else on the car seems to be working, don't think that I have a bad fuse. Question, does power to through the turn signal switch first, before it reaches the emergency flasher? If so, I may be back to bad contacts inside the new turn signal switch and I will renew my efforts to clean it and loosen it up from the outside.
     
  4. Hillbilly

    Hillbilly In Maximum Overdrive

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    Most Fords have both the four ways and brake lights on the same fuse. Got brake lights ? You are looking for a fuse that is powered all the time key on or off. The power goes thru the flasher can first on the four ways, then to the switch. When the four way switch is in the off position no bulbs are connected to the flasher= No load to trigger the flasher to operate. Got to have a constant 12V all the way thru the flasher can going up to the four way flasher switch before you can determine if the switch is bad.
     
  5. tbird9140

    tbird9140 In Second Gear

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    OK Hillbilly, I think you have clearly defined my problem. As I DO have break lights, and yet I don't have power to the flasher can, then my immediate problem is NOT in the turn signal switch. So no reason initially to clean and fiddle with the flasher control on the turn signal switch. After I get power to the flasher can and it still doesn't flash, then I address the turn signal switch flasher control. But in the meantime, good break lights, no flasher power, where would you suggest I look to solve the problem? Is there a short wire in the fuse box that goes from the break light fuse to the flasher? Maybe on the back of the fuse box out of sight and this wire is rusted through, as lost contact, or??? If not that, where is the loss of power likely to be? Alternatively, I guess I could run a jumper from some permanent 12v on to the hot pin on the back of the flasher can. Any suggestions.? Its not like I use the emergency flashers all the time, so if it turns out to be a major headache, I might learn to live without them. Its just that I like to have everything working on a vehicle I restore. Again Thanks.
     
  6. Hillbilly

    Hillbilly In Maximum Overdrive

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    Agree, it is nice to have everything functioning. It is not unheard of to have a bad crimp on a wire on the backside of the fuse block. It is man made and stuff happens. What condition are the fuse retainers, clean or corroded ? I ask to determine if it is possible moisture ate a connection back behind the connectors for the flasher can. It could have been a case of just a few strands of wire got crimped to the connectors and they finally gave up and melted leaving no power to the flasher. If you are moderately brave, remove the fuse box and look for the problem. You have a good idea in jumping power to the flasher from a good 12V source just to check if the switch and flasher then work. All that takes is a piece of wire with both ends stripped to the copper strands. Nothing to loose by trying that first.
     
  7. LSChero

    LSChero In Maximum Overdrive PLATINUM MEMBER

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    Should have two flashers at fuse block.Swap it out with known good unit before replacing switch.Might get lucky..
     
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  8. LSChero

    LSChero In Maximum Overdrive PLATINUM MEMBER

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  9. burninbush

    burninbush In Maximum Overdrive

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    Not sure about your year of car, but on a '70-71 it is the same flasher on blinkers as on emergency lights. So, swap the good one to see if that fixes the problem.
     
  10. Hillbilly

    Hillbilly In Maximum Overdrive

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    On my 70 and 71's they came with two different wattage flasher relays. They used a lower wattage one for the turn signals but as the car's bulbs and wiring aged the turn signal relay got to the point where it couldn't cope with the extra load and cycled so rapidly that the bulbs would barely have time to illuminate. Ford used those low wattage relays to give the driver an indication that a bulb was out because when a bulb blew the indicator on the dash would illuminate constantly. The higher wattage four way relay didn't care how many bulbs it illuminated and cycled at a steady rate. Often owners replaced the turn signal relay with one for four ways to get a nice steady flash rate on their turn signals. The only down side was you had to check your car occasionally to make sure all the bulbs still illuminated. On my 70 and 71's the turn signal relay snapped into a spring clip on the bottom lip of the dash while another spring clip on the column held the four way flasher relay. On a 74, I think both relays plugged into the fuse block. Never ran into one with just one flasher relay.
     
  11. Eri Schwein

    Eri Schwein In Second Gear

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    I am having a similar problem. I have hazard flashers, but no turn signals. I cheeked the flasher, it works on hazard side, and I have 12V on hot side of the turn signal switch in the fuse box, yet no turn signals. I ordered a switch from Rock. Since the hazards work, do you think my turn signal switch is the culprit?
     
  12. 1979 RANCHERO GT

    1979 RANCHERO GT In Maximum Overdrive

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    If the flashers worked before, the new switch could be defective. I would check to see if the switch was EXACTLY the same as the old one, one of the contacts may not be connecting and how many wires come off it and do each wire power up when they are switched on at the switch and down on each side of the plug. Study the wiring diagram LSChero posted on #28 Hopefully there is enough of it there.
     
  13. Eri Schwein

    Eri Schwein In Second Gear

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    I may have not been clear. I have not changed the switch yet. I have hazard flashers, but no turn signals.
     
  14. Eri Schwein

    Eri Schwein In Second Gear

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    The service manual say to remove the lower shroud to access the turn signal wiring. Is this the plastic shroud around the steering column that passes through the dash? Does it snap apart/together?
     
  15. handy_andy_cv64

    handy_andy_cv64 In Maximum Overdrive SILVER MEMBER

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    Yes, and two Phillips screws (accessed from below) hold them together. Then you'll see a curved connector, that is your turn signal switch connector.
     

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