Ive been having problems with my turn signals, i recently replaced the stock signals with LED aftermarket's and it worked perfectly for about a month, then suddenly when i would engage the signal, all four light up. I tried to track down the issue and discovered that when i unplug the instrument cluster they work again. as well my tach stopped working which is also an electrical component, unlike the speed which is a direct cable. Thoughts?

 

My first guess would be something shorted inside the instrument cluster. Wires bared and touching, or water got into the cluster and is shorting out a connection?

 

Do you think a new instrument cluster will fix the problem?

 

You need a new flasher relay that can deal with the low voltage LED draw.

 

I dont disagree but how would that explain why it works when the instrument cluster is disconnected?

 

If something is shorted in the cluster, when you plug it in, then it's likely shorting something else that's plugged into it.

The only reason I suggest the cluster is that the tach stopped working. Otherwise, I would focus completely on what was suggested about the turn signal flasher unit. Using the stock flasher unit (which is designed to flash at a certain rate, based on the load on the flasher, and incandescent bulbs have a much higher load than LED's), and when you plug in LED's to a regular (non-electronic) flasher, sometimes the signals either flash faster (hyperflash) or don't flash at all (just stay on.)

Do you have the original turn signals? If so, try plugging them in and see if there's any difference - this way you're isolating whether it's an LED problem or not.

Maybe it's just coincidence that the tach stopped working as well, which might be a red herring in the troubleshooting.