I have a 1993 jeep wrangler 4cylinder. my left turn signal, when engaged, just stays lit. it wont blink. i replaced all the bulbs and it still just stays on when i try to use the left signal. any solutions?

If bulb or socket melted then replace socket. May be OEM part not sure. Easy fix just be sure to use seal type crimp connectors or you will be working on this a year later.

Check the bulbs again. They can be plugged in two different ways. Sometimes when their put in wrong, the fault you described will occur.

check for a bad bulb. this is how the system alerts you to a non-working light bulb.

The turn signal flasher is sticky and will have to be replace.

Two things I'd look at there...First, though it does not often happen, I'd check all turn signal bulbs to make sure that one of the filaments have not burned and re-connected themselves to the adjacent one inside the bulb. Second, you will need to do a visual check of the switch itself, to make sure the internal contacts have not melted and are not shorting to each other. Only other quick test is to remove the four way flasher and plug it in where the one for the turn signals is. If the one for the signals is burned, it possibly could do that as well. (both flashers are the same) On an 89, there aren't any "modules" so it's a fairly simple system that should not be difficult to diagnose.
Most turn out to be the switch under the steering wheel. Always make sure that all bulb sockets have a good ground.
Good luck

Check the ground wires at the lights are clean and tight.Its a ground problem you have.

i would say you need to replace the flasher fuse for the turn signals.is you radio aftermarket

Probably a bad ground on your front right signal, or a bad bulb. Try switching the right with the left, and see if the problem stays in the same place, or goes with the bulb.

Usually when your signal blinks rapidly it indicates a blown bulb.   Switch on your four-way flashers and check your bulbs at each corner.  On the brake light staying lit, check to see if the left-rear bulb is installed correctly and is the correct bulb for the application.  I've seen people force bulbs in sockets causing the braking element of the bulb to light instead of the parking element.  The braking element is much brighter than the parking element.

sounds like the bulb you have is the wrong resistance the new noen bulbs will do this