Intermittent right turn signal issues

[ForgedCrank]

Tell me what you guys think.. 1994 Ranger 2wd.

On occasion, I will see a condition where my right turn signal will start slow-blinking, and the dash indicator isn't working. I can only hear the switch cycling (except maybe half normal speed). So far, this has only happened when I'm driving so I can't really see if the corner lights are actually working or not while this is happening. I do know when I hit the flasher button, i don't see this symptom... but timing of the events are unknown.
Seems to me that if this was a flasher switch problem, I would see this on both R&L, but so far, I've only seen it happen on the right side. I've tried running the AC and high fan etc trying to put a larger load on the system, cycling the column switch back and forth over and over, but can't reproduce it when I need to. When I get stopped somewhere, I try to get out to observe, but then the problem has vaporized yet again, almost as if it's taunting me.
Electrical stuff is my achilles heel heel, I look at the wiring diagrams in the manual and it's basically chinese to me. I know 12v, on/off, power and ground... throw anything in between and I'm lost.
I've pulled and inspected the front and rear bulb sockets, everything looks pretty dang good, the bulbs are good as well. I cleaned everything up with Deoxit and the power is steady battery voltage (12+). I'm just kind of lost at this point.
If anyone is willing to chime in on how I should start with troubleshooting, i'd be grateful as I've exhausted the extent of my knowledge already.

 

[RobbieD]

Flashers / blinkers need a good ground to operate properly. Make sure that you also inspect your lighting's ground wires and grounding points.

The only other thing that comes to mind is a tired or wonky multifunction switch. When the symptom next pops up, try dicking with and then turning off and re-turning on the turn signal arm. If that affects the issue, I'd suspect the switch.

 

[Curious Hound]

I agree. It’s a loose or dirty connection somewhere, affected by vibration. Or possibly the multifunction switch going bad.

 

[ForgedCrank]

I agree. It’s a loose or dirty connection somewhere, affected by vibration. Or possibly the multifunction switch going bad.

I believe you guys are probably right, seems reasonable, I guess I just like knowing for sure. I get an almost lossless ohm reading between the body and the negative on the bulb socket, so it's definitely something that is 100% most of the time, and less than during brief intermittent times. I suppose it could also be a corroded +V wire somewhere in the line, I haven't chased it all the way from the back to the front yet since I need to get it up on jack stands for that. I've located and checked/cleaned the body ground on the DS fender apron under the hood, that looked good but i did it anyway. From what I've read, that is for the instrument area. The one direct from the battery is very good as I already cleaned it when I did the engine work. I took it off and looked at it, cleaned it again for giggles. There is another ground strap from the intake to the firewall that i just looked at, again, nice and clean but I hit it again anyway.
I wish I knew if the rear one flashed when it was broken and I turn on the hazard lights. I just can't catch it in that state at the same time. I know it's parts-cannon methodology, but I recon i'll just order a column switch for it and light the fuse. It's at least a reasonable guess.

 

[ForgedCrank]

Hey while I have your guys attention, any idea what this plug is for? It's on the DS near the underhood fuse dist box and goes into a main wiring harness There was never anything plugged into this and i can't figure out what it's for. Could this be the reason I have no cruise control by chance?

 

[RobbieD]

I wish I knew if the rear one flashed when it was broken and I turn on the hazard lights. I just can't catch it in that state at the same time.

If memory serves (no guarantee on that one!) at night you can see light from the tails through some small holes in the inside bed sheet metal in the corners. If you don't have a bedliner, and set your rearview to "day", I *think* (see disclaimer) that you can see what the tails are doing, light-wise.

any idea what this plug is for?

Diagnostic connector. If you get an OBD1 code reader, that's where it plugs in.

 

[ForgedCrank]

If memory serves (no guarantee on that one!) at night you can see light from the tails through some small holes in the inside bed sheet metal in the corners. If you don't have a bedliner, and set your rearview to "day", I *think* (see disclaimer) that you can see what the tails are doing, light-wise.



Diagnostic connector. If you get an OBD1 code reader, that's where it plugs in.

I do have a bedliner installed hehe.
I'm was thinking of putting a parasite bulb on there and taping it inside of the tailgate so I could see the thing. I can see the front flashing for sure when it reflects off of stuff, I haven't been in a spot yet where I can see the back one in a similar manner. Then by the time I AM near something behind me for it to reflect, it's not doing it anymore. Intermittent stuff sucks.
Interesting on the OBD... all this time I thought the interface was the connector under the steering column near the hood latch handle.
Anyway, I'm going to go the rookie route I suppose and just buy the column switch and cross my fingers.

 

[Curious Hound]

Hey while I have your guys attention, any idea what this plug is for? It's on the DS near the underhood fuse dist box and goes into a main wiring harness There was never anything plugged into this and i can't figure out what it's for. Could this be the reason I have no cruise control by chance?

View attachment 116415
View attachment 116416

Like Robbie said, that’s your diagnostic test port. You don’t have to have a reader. You can use a test light. You can also use a jumper wire and read codes with the CEL on the dash. One port on there can be used to energize the fuel pump relay for testing. There is more info in our tech library.

fast forward to around the 16:55 mark in this video.

 

[Curious Hound]

At night, back up to a garage door or wall and watch for the lights to reflect off the surface.

there is a ground connection on the rear frame crossmember for the tail lights.

 

[ForgedCrank]

Ok, more info... I had some bits incorrect.
I was able to witness the issue again last night in the dark finally, and was able to see all of the lights.
At all times, all of the external bulbs are working. At seems that the issue appears after driving for some time, I don't know if this is a heat related thing or what. This happens every time when I drive, it just takes a little while for it to appear. I want to think it is only happening at night, but that is more likely because in the daylight I'm just not noticing the indicator isn't working. When the issue re-appears, the left turn signal continues to operate normally. the right turn signal flashes at a slightly slower speed and the right dash indicator does not work at all. Also, while the malfunction is active, the hazard lights work normally, except the same right-hand dash indicator does not flash. Shutting it down and and restarting doesn't help anything. When I got home I was able to walk around it and I don't see anything odd with the external lighting, all lights on it are working and even brightness. So basically, there is no right-hand dash indicator and it flashes slightly slower when this happens...
I think this rules out the column switch? Someone mentioned a ground on the rear frame crossmember, but I've been over it no less that 4 times and I don't see anything at all on the rear crossmember or even the bumper as far as grounds go, I only have a couple of plastic push-in harness mounts. I don't know where else to look at this point.
I've checked and cleaned the ground on the DS fender apron, and the one from the intake to the firewall, as well as the one from the battery to the engine block. Are there anymore hidden ground points I may be missing?