Fast turn signal

apspainting

Member
Mar 7, 2014
21
2
14
00 mustang gt vert drivers side only flashing rapidly. Checked all grounds i could find, bulbs, switched out yellow relay and no change. Any ideas? Passenger side words as it should.
 
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Most Lights are dual filament.
One for blinker, one for lights.
Check the side markers as well?
The system senses changes in electrical current, causing the blinker to run twice the speed to indicate a bulb is out in the system.
But, it’s cut & dry, i.e., the bulb may work but resistance changes elsewhere due to a loose -or bad connection, even corroded fuse blades, anything on that side of the flasher circuit, the system reacts identically.
Go through all the bulbs, led’s in place of incandescent bulbs may cause this, all connectors, pins inside, chafed wires, moisture, etc.
Flasher relay may also cause it, but most often it’s a bad connection, not the flasher relay itself.
Rest assured that it’s usually so simple, you’ll miss it 1st pass & kick yourself when you do find it. Take your time, It’ll likely be right at one of the sockets.
Best of luck!
John
 
Most Lights are dual filament.
One for blinker, one for lights.
Check the side markers as well?
The system senses changes in electrical current, causing the blinker to run twice the speed to indicate a bulb is out in the system.
But, it’s cut & dry, i.e., the bulb may work but resistance changes elsewhere due to a loose -or bad connection, even corroded fuse blades, anything on that side of the flasher circuit, the system reacts identically.
Go through all the bulbs, led’s in place of incandescent bulbs may cause this, all connectors, pins inside, chafed wires, moisture, etc.
Rest assured that it’s usually so simple, you’ll miss it 1st pass & kick yourself when you do find it. Take your time, It’ll likely be right at one of the sockets.
Best of luck!
John
I now have front and rear lights and harness out in the open so I can look at everything, but nothing i can see so far. This is driving me crazy. I might just replace both sockets to eliminate those and bulbs. All wires look good too. Hazards work normal so does passenger side. Your right, I'm sure it's right under my nose. Thanks for the reply!
 
Changed out both front and rear with led and sequential, but same thing is going on. Changed back to only stock bulbs and no change. No dash lights Changed. Went back to all stock just to see but no difference
 
I now have front and rear lights and harness out in the open so I can look at everything, but nothing i can see so far. This is driving me crazy. I might just replace both sockets to eliminate those and bulbs. All wires look good too. Hazards work normal so does passenger side. Your right, I'm sure it's right under my nose. Thanks for the reply!
Hi,
I sorry to hear this has you vexed, yes- anything on that side including the wiring/controls within the dash. Here’s a helpful link to assist you further along.
Was going to ask if by manipulating the directional switch with additional light pressure or manipulation while lights were flashing, things change....
I’ll ask some purposed questions to help narrow things down, tests laid out may help locate further.
Try cranking sharply to the left or right, If a tilt setup, try moving it in different positions to see if anything changes.
When this began, did it suddenly start or occur here and there over time?
Was there anything done to the car preceding this that may account for it?
E.g., seeking a power supply wire & finding it wasn’t compatible, taped it up- now vulnerable, etc..
Car was running led’s when this began, now back to filament-type of exact OE wattage?
Moisture is the enemy here, one drop in the right location is all it takes. Have any known leaks anywhere, If a connector or fuse block had/has evidence of moisture inside, focus further on that.
Recent heavy storms of late?
Have a shop manual? If not- 25$ will gain you one at a local parts store. Diagrams & guidance are priceless.
You did pull fuse(s) & clean blades & sockets? Replace the fuse(s) associative with flashers with new stock amperage counterparts to rule out fuse overheat, where the element- though damaged, remains intact.
If comfortable in doing so, you can get in series with wiring using a feed through Ammeter setting on a VOM to measure Amperage from beginning of harness where left and right directional wiring splits off & compare while energized...
Or, same idea with battery disconnected using an Ohmmeter from beginning & sockets to end of each harness. Check Pos to Ground at every socket to locate weak connections between, leakage.
Perform Wiggle testing of all the wiring while flasher is on to locate change.
Perform basics to ensure battery voltage is correct (12V+) and Alternator output is 13.7V+ with engine running.
If on the low side, charge the battery for a while, remove, retest signals.
Clean your terminals and start there whilst ensuring solid connections from ground terminal to chassis, block, checked for corrosion/rust. Solidify. Continue moving outward with basics.
Same with the positive terminal to fuse block, see to it all connections are solid and corrosion free.
Flasher relay replaced, check it’s socket for corrosion, sprung pins fully making solid contact and carefully clean. Close pins with a small pick if questionable.
Verify if one flasher relay alone is involved while viewing diagrams.
Only when all testing options are exhausted should you enter the column.
Enabled Directionals do reset automatically when going around a corner & steering wheel straightens out.(Clockswitch).?
This occurs whether Car is running or not with Key on?
Flasher lights on dash work OK, speed is also escalated or normal?
Please use every safety precaution whilst working in close proximity to the airbags within the column!!

Please elaborate on the comment below, Hazards do/do not function on both sides? Or are you meaning hazards are fine, yet the issue with the rapid directional. Dummy here, can’t interpret, lol!
“Why would hazards be right and passenger, but no driver side? The only other thing I can think of is the multifunction switch in the column”

If I’m interpreting correctly, Hazards are not generally bound by the same rules as regular turn signals. Emergency purposed, wired to work-period. if one’s out, the rest run for less confusion.
I’ll clarify by viewing the wiring diagram.
If you don’t have the wiring diagram, I’ll find the Manual & will post one... it’s really necessity at this point.
PS: Have an aftermarket Stereo with a large Amp ?
Best of luck!
John
 
Hi,
I sorry to hear this has you vexed, yes- anything on that side including the wiring/controls within the dash. Here’s a helpful link to assist you further along.
Was going to ask if by manipulating the directional switch with additional light pressure or manipulation while lights were flashing, things change....
I’ll ask some purposed questions to help narrow things down, tests laid out may help locate further.
Try cranking sharply to the left or right, If a tilt setup, try moving it in different positions to see if anything changes.
When this began, did it suddenly start or occur here and there over time?
Was there anything done to the car preceding this that may account for it?
E.g., seeking a power supply wire & finding it wasn’t compatible, taped it up- now vulnerable, etc..
Car was running led’s when this began, now back to filament-type of exact OE wattage?
Moisture is the enemy here, one drop in the right location is all it takes. Have any known leaks anywhere, If a connector or fuse block had/has evidence of moisture inside, focus further on that.
Recent heavy storms of late?
Have a shop manual? If not- 25$ will gain you one at a local parts store. Diagrams & guidance are priceless.
You did pull fuse(s) & clean blades & sockets? Replace the fuse(s) associative with flashers with new stock amperage counterparts to rule out fuse overheat, where the element- though damaged, remains intact.
If comfortable in doing so, you can get in series with wiring using a feed through Ammeter setting on a VOM to measure Amperage from beginning of harness where left and right directional wiring splits off & compare while energized...
Or, same idea with battery disconnected using an Ohmmeter from beginning & sockets to end of each harness. Check Pos to Ground at every socket to locate weak connections between, leakage.
Perform Wiggle testing of all the wiring while flasher is on to locate change.
Perform basics to ensure battery voltage is correct (12V+) and Alternator output is 13.7V+ with engine running.
If on the low side, charge the battery for a while, remove, retest signals.
Clean your terminals and start there whilst ensuring solid connections from ground terminal to chassis, block, checked for corrosion/rust. Solidify. Continue moving outward with basics.
Same with the positive terminal to fuse block, see to it all connections are solid and corrosion free.
Flasher relay replaced, check it’s socket for corrosion, sprung pins fully making solid contact and carefully clean. Close pins with a small pick if questionable.
Verify if one flasher relay alone is involved while viewing diagrams.
Only when all testing options are exhausted should you enter the column.
Enabled Directionals do reset automatically when going around a corner & steering wheel straightens out.(Clockswitch).?
This occurs whether Car is running or not with Key on?
Flasher lights on dash work OK, speed is also escalated or normal?
Please use every safety precaution whilst working in close proximity to the airbags within the column!!

Please elaborate on the comment below, Hazards do/do not function on both sides? Or are you meaning hazards are fine, yet the issue with the rapid directional. Dummy here, can’t interpret, lol!
“Why would hazards be right and passenger, but no driver side? The only other thing I can think of is the multifunction switch in the column”

If I’m interpreting correctly, Hazards are not generally bound by the same rules as regular turn signals. Emergency purposed, wired to work-period. if one’s out, the rest run for less confusion.
I’ll clarify by viewing the wiring diagram.
If you don’t have the wiring diagram, I’ll find the Manual & will post one... it’s really necessity at this point.
PS: Have an aftermarket Stereo with a large Amp ?
Best of luck!
John
Thanks for all that information. I've now taken out the multifunction switch and sprayed it out with electrical cleaner, but still no change. It's got to be the rear socket since I can't just swap that one out. That's next. I will post what I find. Thanks again
 
Did you try changing the flasher module at all? If not, it couldn't hurt. It's cheap enough and pretty simple.

A little while back I had this weird, erratic turn signal issue. Sometimes they'd turn on, sometimes they wouldn't. But the hazards worked. I made sure all the bulbs were fresh and I even changed out the multifunction switch...none of that worked. The last resort was the flasher module, so I swapped that and voila, they started working properly again.
 
How recently did this start?

Were any changes made that might warrant the odd behavior? I did notice mention of the LED/sequential swap...were the signals working properly before the swap, and immediately after?

Vexing indeed.
 
Well the car has been sitting for like 3 years doing body work, but I can't remember if it did that or not. I want to say I wouldn't have let that go while I was driving it. I removed all new light and just used the stock sockets and bulbs but no change.
 
It ended up being a prong inside the rear VIIIThe connector that was bent and not making a connection. Thanks for all the help. Was
Hi,
Great, glad you found it! Doesn’t take much
Its simple things than get ya’& now that you’re a pro at it- It’ll never happen again. Such as life..relentless Irony, lol Use a little electrical grease inside on the connection to protect it from moisture.
Best!
John