Turn indicator & brake light continuous flashing, Started with a bad bulb |
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Turn indicator & brake light continuous flashing, Started with a bad bulb |
bzettner |
Sep 12 2021, 08:02 AM
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#1
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Member Group: Members Posts: 211 Joined: 2-June 13 From: San Antonio, TX Member No.: 15,951 Region Association: Southwest Region |
'73 1.7, driving along (IMG:style_emoticons/default/driving.gif) both dash turn indicator lights and brake light started flashing continuously (IMG:style_emoticons/default/WTF.gif) . Found out I had a burned out turn signal bulb. Did my 914World searching and learned the flashing is to "let you know" you have a bulb out, great! Changed out the bulb, flashing continues. Cleaned light socket contacts, bulb ends, changed out bulbs in matched pairs, replaced flasher unit with new RockAuto unit, still continual flashing. Added a little brake fluid, no change.
All my lights work as designed, all of them. Dash turn indicators are bright and work individually when used. The new flasher unit causes the dash indicators to flash continually dimmer than the original unit. I have found a white w green strip wire near the flasher unit that has no connection, no fitting, just a blunt cut wire with no obvious "answer" to its placement. I am NOT a great schematic guy (IMG:style_emoticons/default/headbang.gif) . Something changed! Ideas? Attached thumbnail(s) |
Spoke |
Sep 13 2021, 03:55 PM
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#2
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Jerry Group: Members Posts: 6,991 Joined: 29-October 04 From: Allentown, PA Member No.: 3,031 Region Association: None |
When you say the turn signal indicators flash continuously is this with the key on and no turn signals on? Both flash?
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bzettner |
Sep 13 2021, 09:31 PM
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#3
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Member Group: Members Posts: 211 Joined: 2-June 13 From: San Antonio, TX Member No.: 15,951 Region Association: Southwest Region |
When you say the turn signal indicators flash continuously is this with the key on and no turn signals on? Both flash? Yes, start the car, shut the door, release the E-brake (stops the red flashing brake light) and the dash turn signal indicator lights both blink at the same time, continuously. If you put on the right or left blinker, they work like they should until the blinker is turned off. Besides this, all lights, flashers, turn signals brake light, tail lights, hi/lo headlights and aftermarket fog lights all work as they have since 2013 when I got this car. |
Spoke |
Sep 14 2021, 04:40 AM
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#4
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Jerry Group: Members Posts: 6,991 Joined: 29-October 04 From: Allentown, PA Member No.: 3,031 Region Association: None |
When you say the turn signal indicators flash continuously is this with the key on and no turn signals on? Both flash? Yes, start the car, shut the door, release the E-brake (stops the red flashing brake light) and the dash turn signal indicator lights both blink at the same time, continuously. If you put on the right or left blinker, they work like they should until the blinker is turned off. Besides this, all lights, flashers, turn signals brake light, tail lights, hi/lo headlights and aftermarket fog lights all work as they have since 2013 when I got this car. It is strange that the turnsignal indicators flash since there's a 2nd relay in the flasher to detect heavy exterior bulb current to power the indicators on pin K on the flasher. The flasher should only operate when there's a load on terminal 49a. In the diagram, the only paths to ground are the 4-way switch, turnsignal switch or brake warning indicator. One test is to remove the wires on the master cylinder warning switch under the car and the ebrake wires. Something is creating a load or leakage on terminal 49a. If the new flasher didn't solve the issue then the original flasher should be ok and should be reinstalled. While the flasher is out, measure the resistance from the plug terminal 49a to ground. It should be infinite since every path to ground goes through a switch thus should be an open circuit. Attached image(s) |
bzettner |
Sep 14 2021, 06:49 AM
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#5
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Member Group: Members Posts: 211 Joined: 2-June 13 From: San Antonio, TX Member No.: 15,951 Region Association: Southwest Region |
[/quote]The flasher should only operate when there's a load on terminal 49a. In the diagram, the only paths to ground are the 4-way switch, turnsignal switch or brake warning indicator.
One test is to remove the wires on the master cylinder warning switch under the car and the ebrake wires. Something is creating a load or leakage on terminal 49a. If the new flasher didn't solve the issue then the original flasher should be ok and should be reinstalled. While the flasher is out, measure the resistance from the plug terminal 49a to ground. It should be infinite since every path to ground goes through a switch thus should be an open circuit. [/quote] As it sits, I have everything accessible, albeit a contortionist warmup exercise to use two hands and both eyes. I'll check continuity later today. Thank you for your help! |
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