I recently had the turn signal relay in my 1994 Jeep Grand Cherokee replaced due to regular/intermittent malfunctions.
Prior to the replacement of the part, there would be unpredictable occasions when the signals (hazards included) would not work. Sometimes they would stop working in the middle of use, or sometimes they just wouldn't work from the time the car was started. Most of the times, once they'd stopped working, they wouldn't start working again until the next time the car was used. Once in awhile though, it would clear up mid-drive.
After the part was replaced, the signals work fairly reliably. However, there have been a couple peculiarities since.
For one, the first lighting of the signal will always be much longer than the remaining blinks. When I switch the signal on, it will light for nearly a full second before cutting off and going into a regular blinking rhythm.
The issue that has me really scratching my head though, is that on rare occasion I will hear just a single click from the signal without any provocation. There does not seem to be anything in particular that sets this off, and it does not consistently occur around any time during which I've actually used the signals. Additionally, when the click is heard, I do not observe any indications that any of the signals have actually turned on or off.
What could be causing this sort of anomaly? Is this likely to be a hazard (pardon the pun) to the health of the system or components in the long run?
EDIT - Some more details I've noticed as the problem has persisted:
The issue is more prominent during the morning, or in cooler and more humid weather. Occasionally, instead of just one click, it will be a long series of rapid clicks as if something is jammed. While on some occasions the symptom seems entirely unprovoked, it often coincides with a press of the brake pedal. When the "jamming" occurs by this trigger, releasing the brake seems to relieve it.
It used to be that the only time I could reproduce the problem was in the mornings. Now, it seems that it happens almost any time the car is started "cold", and gradually lessens as the vehicle warms up. The "jamming" has not happened in awhile, but the click-with-brake happens more regularly now.
I took the car to the shop awhile ago to have the issue checked, but of course they were unable to reproduce this intermittent problem. Perhaps I'll give it another shot, now that it's happening more often.
EDIT - New detail.
It seems the reason this problem seems more prominent in the morning, or in cooler humid weather, is because the rear defroster somehow exacerbates it. I was late in kicking that on this morning, and noticed that the instant I did was when the signal clicker did its "jamming" thing while braking. The issue does still happen from time to time without the rear defroster, but there's a marked increase in the frequency and severity when it is on.