Turn signal and headlights |
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Firstimer
New Member Joined: 28-June-2020 Location: Alberta Status: Offline Points: 8 |
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Posted: 13-August-2021 at 2:42PM |
Hi all. I'm starting to work through my 70 Torino Brougham and would like to get it to the point where I can safety it. Ontario Canada standards are fairly rigid. I have most of the items squared away but I am tackling an electrical problem that I can't narrow down.
All the lights work incl: turn, headlights, tail license plate, markers etc...but when I turn the headlights on, my left side markers have about half the voltage that the right side does and the front left running light is also very dull. When I turn the left turn signals on...nothing. Turn the right on, no issues. The left turn signal on the dash remains on from the moment I turn the headlights on, regardless of turn signal position. I first thought of it as a ground issue. I checked the grounds in the trunk but I can't find any up front to check. Are there any? After that I tried to see if it was a short between the markers and turn signals but I can't find anything. The only wiring I have not checked is under the dash. Could this be a relay or turn signal switch issue or are there grounds I'm overlooking. Help would be appreciated. I don't think it matters, but the turn signal bulbs on the front are led bulbs as well as the back. I don't think that is the problem because the right side works fine headlights on or off, whereas the left side just doesn't want to cooperate with the headlights on. Thanks again. |
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californiajohnny
Moderator Group Joined: 05-October-2013 Location: winlock, wa Status: Offline Points: 14609 |
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there should be a ground wire on each side near the headlight
the dash bulb on with running lights on usually indicates a bulb out on that side either front or rear... |
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JOHN
74 GRAN TORINO S&H CLONE 74 VETTE CUSTOM 90 S10 BLAZER 4X4 LIFTED 77 CELICA CUSTOM 75 V8 MONZA SUPERCHARGED 79 COURIER VERT. SLAMMED 75 VEGA V6 5 SPD 70 CHEV C10 P/U 68 MUSTANG FB CONVERSION |
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Firstimer
New Member Joined: 28-June-2020 Location: Alberta Status: Offline Points: 8 |
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Thanks for that. I've spent a few hours trying find the grounds up front. Nothing. The electrical diagram indicates there should be something but I can't find anything. The wiring harness looks original and I havnt found evidence of wiring mutilation...Well on the front end anyways.
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72FordGTS
Admin Group GTS.org Admin Joined: 06-September-2005 Location: Ontario, Canada Status: Offline Points: 5846 |
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It does sound like a bad ground issue. Like John says, there should be a ground somewhere near the end of the headlight harness. I am not sure in a '70 OTOH, but maybe a member with a 70-71 can post a pic. Also check the turn signal sockets to make sure they are in good shape and making good contact. If you have a regular bulb, it might be worthwhile to replace the LED just to rule out the LED as being the issue.
I am not sure what wiring diagram you are using, but we have a 1970 wiring diagram download here: |
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Vince
1972 Ford GTS Sportsroof - Survivor, One Family car GTS.org Admin |
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Firstimer
New Member Joined: 28-June-2020 Location: Alberta Status: Offline Points: 8 |
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Thanks for that link. That is the wiring diagram I have been using. I disconnected the turn signal socket from the main harness and am only getting about 4-5v at the connection with the headlights on. So it almost seems like something else in the system is causing low v9ltage to the turn signal and left markers. I'm not a wiring or electrical person at all so I could be wrong in my approach.
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Rockatansky
Senior Member Joined: 30-July-2010 Location: On The Road Status: Offline Points: 6072 |
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IMO the 1st step when working a problem like this; remove & inspect every bulb for correct type and bench test each for function or just replace them straight away. at the same time inspect & test the sockets and be prepared to replace them as needed also Yes there should be a ground near each headlight pigtail, they may be well hidden in the radiator core support. you might even have a better chance of finding them from under the car? the schematic shows the grounds coming off the high beam headlight on one side and the low beam on the other. and being a ground issue it can be coming from the back end of the car just as easily
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72 GT Ute
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californiajohnny
Moderator Group Joined: 05-October-2013 Location: winlock, wa Status: Offline Points: 14609 |
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yes they are usually coming right off of the headlight connector, should be something similar at the tail lights too
4-5 volts? sounds like a corroded connection somewhere??? if it's been sitting a long time try working the switch off and on a bunch of times to scrape a clean connection! could be the switch is bad... |
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JOHN
74 GRAN TORINO S&H CLONE 74 VETTE CUSTOM 90 S10 BLAZER 4X4 LIFTED 77 CELICA CUSTOM 75 V8 MONZA SUPERCHARGED 79 COURIER VERT. SLAMMED 75 VEGA V6 5 SPD 70 CHEV C10 P/U 68 MUSTANG FB CONVERSION |
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AUS GTS
Senior Member Joined: 26-July-2021 Location: Australia Status: Offline Points: 383 |
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Had similar issues with mine that hadn't moved much for a couple of years...replaced flasher & a couple of faulty bulbs & cleaned up the sockets... came good after that.
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Al
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Firstimer
New Member Joined: 28-June-2020 Location: Alberta Status: Offline Points: 8 |
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Thanks all. I've replaced all the marker lights and was able to get all turn signals and markers to work how they should when using the hazard lights with the headlights on...but the left turns still dont want to work as they should with the headlights on. I've gone through the front end with a fine tooth comb and havnt found any grounds. If anybody has a pic of their grounds on a 70/71 model I'd appreciate it. I will probably order a couple flasher relays tonight and the front turn signal sockets as they are starting to look a little rough. Pending the ground situation my next thought is the turn signal switch which I havnt touched yet at all. I tried to clean up all the connections too.
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Big Bird
Senior Member Joined: 25-August-2013 Location: New York Status: Offline Points: 4194 |
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First, take all the LEDs out. Every last one. Put in real bulbs and try the lights again. LEDS are finicky about current. Voltage and amperage, iffy connections, dirty contacts.
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"What we do in full frontal view, is more honest than your cleaned-up mind."
Randy 1979 T-Bird 2005 F-150 STX RCSB 4.6, 3.55 LSD How the Heck does a REGULAR CAB SHORTBED weigh over 5200 pounds? |
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Rockatansky
Senior Member Joined: 30-July-2010 Location: On The Road Status: Offline Points: 6072 |
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trace the black wires from the headlight pigtail connectors, as the diagram shows 1 on each side will be your grounds or verify which of the headlight connector wires are the grounds and test with temporary jumpers to Bat - have you compared voltages at the headlight bulbs?
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72 GT Ute
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handsofstone
Senior Member Joined: 13-April-2018 Location: Northeast Status: Offline Points: 3946 |
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The grounds are on the radiator support. Each side near the headlights. Someone may have missed grounding at some point.
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Firstimer
New Member Joined: 28-June-2020 Location: Alberta Status: Offline Points: 8 |
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Good news. It's all sorted. It ended up being the little led bulbs in the front turns. As soon as I replaced those everything worked like a charm. On another note, I still can't find any grounds from my headlight pig tails. I'm assuming something must have been done at at some point to change the original setup. Basically every front light wire disappears into an electrical tape wrapped wiring harness with the only black lead protruding to the surge protector box near the starter coil. I've spent hours trying to find the grounds and short of removing the current harness, I lost the battle. Either way, problem solved for the time being but it would still be nice to see what OE looks like for reference.
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AUS GTS
Senior Member Joined: 26-July-2021 Location: Australia Status: Offline Points: 383 |
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...... good stuff
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Al
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Rockatansky
Senior Member Joined: 30-July-2010 Location: On The Road Status: Offline Points: 6072 |
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that's wild
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72 GT Ute
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handsofstone
Senior Member Joined: 13-April-2018 Location: Northeast Status: Offline Points: 3946 |
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For LED bulbs have to a new flasher. The 194 replacements that you need have 5 lights on each bulb. I don't think you can mix and match them. I did all my tail, turn, and markers with LED and no issues.
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