Resolved Signal light Issue

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Hello, I made an account to try to find answers to my signal light issue I have on my 2004 Mustang V6 3.9L 40th anni. I noticed it not to long ago that whenever I turn left, my dashboard left turn signal light does not come up but my head/taillights do work fine and blink (the clicking blinking noises do come up). The right turn signal light does work normally. Oh and I did try turning on the emergency lights and the left turn signal on the dash still doesn't turn on but the head/taillights still blink as normal. ALSO when engaging the turn signals on either Left or Right, they stop working entirely sometimes after 5 to 10 sec or just not engage at all. I have to reengage my turn signal. BTW too my turn signal switch is a little loose but I don't know if that's whats causing the issue or if it is but I want to make sure that's why I am here asking. If anyone has any questions feel free to ask, I will answer. Thank You!
 
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The issue with the left turn signal indicator on the cluster sounds like you may just have a bulb out in the cluster. There are some videos on YouTube for how to remove the cluster to replace the cluster backlight bulbs, not usually the indicator warning light bulbs. Kind of a pain to pull out, so you may want to decide if you want to upgrade the backlight bulbs or the gauge face while you are at it.

This thread on another forums talks about the bulb type for the indicator/warning lights, as I don't see the bulb listed on my usual parts sites:

Not sure on the turning off/not starting issue. Do the hazards ever do that? If not, I'd think turn signal switch, otherwise possibly the flasher relay.
 
The issue with the left turn signal indicator on the cluster sounds like you may just have a bulb out in the cluster. There are some videos on YouTube for how to remove the cluster to replace the cluster backlight bulbs, not usually the indicator warning light bulbs. Kind of a pain to pull out, so you may want to decide if you want to upgrade the backlight bulbs or the gauge face while you are at it.

This thread on another forums talks about the bulb type for the indicator/warning lights, as I don't see the bulb listed on my usual parts sites:

Not sure on the turning off/not starting issue. Do the hazards ever do that? If not, I'd think turn signal switch, otherwise possibly the flasher relay.
So yes I did check the bulbs and the left one was indeed out. And yes it was a hassle to remove. I did end up replacing it and worked flawlessly. Only issue is the turn signals recently STOPPED working completely both on the dash and the tail/headlights. The emergency flashers work perfectly from both inside and outside. I did check the relay and it was the relay giving me issues. Only
problem I had was I did get a replacement relay from autozone and i noticed it was missing a prong. So instead of having 6 prongs from the original relay, it had 5 instead. plugged it in and everything and the turn signals now stay on when turning? No blinking just stays on until i disengage it. I dont know if it might be the relay not having that extra 6th prong or something but I searched everywhere that it doesnt need that 6th prong. so Im a bit confused?
 
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I noticed the same when I replaced mine with an EP27 to prevent hyperblink with LED bulbs. Seen other forums with the same question on other Ford's like Ranger. I assume it is a no connect or extra ground/pin on the stock one, since there are only 5 wires going into the connector (Blk, Blk/Y, Blue, Red/Wh, White/Red). Mine has worked fine, Haynes manual also shows only five wires into it.
 

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I noticed the same when I replaced mine with an EP27 to prevent hyperblink with LED bulbs. Seen other forums with the same question on other Ford's like Ranger. I assume it is a no connect or extra ground/pin on the stock one, since there are only 5 wires going into the connector (Blk, Blk/Y, Blue, Red/Wh, White/Red). Mine has worked fine, Haynes manual also shows only five wires into it.
Yes so it didn't really matter the 6th prong, I just got a replacement from rockauto and installed it and it works like a charm, thank you so much for the help and info, im new to all this forum stuff so my apologies for the super late replies and for my lack of knowledge about this, new to the mustang community hehehe. Thank You very much tho dude, helped me alot with my doubts and second guesses!