Signal LIght Question (w/ Pic)

[Dawn Michelle]

On this one  - the turn signal works, but not the running/parking light filament.  I have switched the working side bulb with this one so verified the issue is with the socket/wiring not the bulb.  Do I look for a new base?  Cut into the rubber sleeve and check the wire connections?

[Rich Thomas]

It looks pretty crusty Dawn but first thing try to clean the solder connections inside the socket and re try

[Dawn Michelle]

Thumbs up! 

[Rich Thomas]

Sorry I had to bail on you Dawn but glad you was able to get good info. A cleaning tip for those nasty little sockets. If you or your Pops have a shot gun cleaning kit laying around? some times you can take a bore brush of the right size and some good old Burchwood Casey or hopes bore cleaner, you can do a good job of cleaning the whole inside of those sockets. Power off of course. Then a dose of WD40 to seal the deal. You can get dielectric grease at the auto parts store to help keep the nasty green stuff from coming back but it's really better for the modern bulb sockets. Wd 40 is a dielectric as well and gets into places the grease can't. And there is always the electric contact cleaners that leave a film protection but some, if not all them, are nasty for your health. hope the light shines on have a good evening.

[John "T" Nordhoff]

 Those dual filament bayonet bases are cheap simple n easy to replace and rust isn't a good thing so it may need replaced HOWEVER first use a simple 6/12 test light to insure the three wires to the socket (turn and stop,,,,,,,,tail,,,,,,,,,,,,,,,,and ground) are all good and working. A cheap simple 6/12 test light is a MUST in an RV.  If you can attach the alligator clamp lead to a good know ground the test probe is  sharp pointy so you can stick/punch it in the hot wires to look for 12 volts. Often on those lamp sockets its the springy under the inside flat round base that isn't pushing out hard enough to make good electrical contact with the bulbs two lead contacts. If you're careful (dont touch sides) you can stick the probe end of the test light down inside the barrel to contact the two terminals to see if voltage is present so you don't have to stab thru the wiring. To the extent you can get to the inner contacts with the power off a small thin wire/brass brush may allow you to clean shine the inner two contacts in the inner flat round base. Also I always shine the bulbs terminals. It don't take much rust or corrosion or even gray oxidation or a lack of springy to make the lights not work.

 John T

[Dawn Michelle]

All makes sense -more thanks...

[Terry H]

It is quite amazing how many 12V issues are traced to a poor ground connection.

[John "T" Nordhoff]

 Terry THATS EXACTLY RIGHT. In years of farming and working on and buying and selling trailers and RV's and tractors etc. etc. when there were lighting problems IT WAS OFTEN DUE TO A POOR GROUND CONNECTION/CIRCUIT.

 Dawn, if the bayonet socket is badly corroded or all gunked up, sure cleaning and brushing as I suggested can help the problem, BUT IF ITS VERY BAD I SUGGEST YOU JUST REPLACE IT and be done with it. In your situation if one of the circuits (stop or tail) works fine but not the other the ground is likely okay there.

 Get your 6/12 probe tip tester and have at it lol

 Best wishes,

 John T  Tooooooooo long retired Electrical Engineer and rusty as an old nail lol   

[Dawn Michelle]

Okay guys, cleaning didn't work.  I did strip down the heat shrink on the backso I could identify the ground wire (black), and shining a flashlight into the base, while I couldn't see much, didn't see any obvious corrosion or loose connection.  I was just about to clip the wires and see about getting a replacement when "pops" (lol Rich, but good idea to ask) suggested pushing a straight pin from the sewing kit through my wires first and testing with the multimeter to ensure I was getting voltage.  Since we all seem to agree we have the situation where one wire is the blinker filament and one wire is the running light filament.  Then my results might make sense:

Green wire - blinker, varying voltage when on, corresponding to the blinking.

Brown wire - nada, nothing.  

Now to test the theory properly I need to open the other side and apply the same test but we are having a wee thunderstorm roll in so I packed it in for the day.

If testing pans out, and brown wire on the working light is getting voltage, then we can assume I have an issue with my wiring or connection back down the line?

Also, got that dang battery back in guys - thanks.  Replaced the rods and with some jiggling got the plate low enough for the battery to fit (after I removed the radiator overflow housing - 3 screws not the end of the world).  Used some rubber strapping, some wood to help jam it against one side of the plate where it has a lip and then used the plastic handle for now as a buffer so the positive doesn't connect with the side of the truck - and I understand I can get rubber terminal covers to just be extra safe.

Of course now that I have it back in, I can't access that stretch of wiring nearest the light - lol - but I'll do some more testing first before I take it back out.  Next season will sand and rustoleum that plate but it's solid for now.  Also will need to work on the wheel well.  

And, that running light can wait too - not a fan of night driving (ever since I pegged that granddaddy raccoon in nowhere west texas in the wee hours and took out a whole bunch of my grillwork and fans on my bug)...unless they tag it on my safety inspection coming up...but will worry about it then.  Still have a couple of years before I'm exempt.

 

[Lakota Wolf]

If your not getting juice on the *running light wire,(brown) and ya sneak back down the wiring a little more and still nothing,, then its at the split wire junction, (Thats a place an engineer specifically hid in an area that is not feasable without complete removal of the cab from the frame),(bad joke).

Tracking back is a timely process,,Running lights run off a single feed wire and are split at a general location which varies, and sometimes can be found easily, other times never ever.

I would use you needle punch technique and stab and check as far back as you can. Murphys law occasionaly set in and I have had wires in the worst places, corrode through, usually far beyond the light socket.Wire chasing is always fun,,,, Said NO ONE EVER. There is a cheat short cut to a repair that you have, but I will have to disclose that secret later.. (Requires a big oak tree with a nice shade branch overhead).

[John "T" Nordhoff]

 Dawn, Looks like I agree with the good Wolf man again. As I noted earlier the alligator clamp end of a 6/12 volt test light to a known good ground and the sharp pointy end stuck thru the insulation down into the wire will answer many questions and you dont have to cut any wires yayyyyyyyyyyyy If no test light a volt meter with a fine sharp tip probe end  can do the same thing pushed down thru the insulation to contact the  inner wire

 YES if theres no voltage on the brown (tail marker) wire the bulbs NOT gonna work. If the other side works its not too hard to trace back where the 2 browns (left and right) splice and find the problem. If one side is hot but NOT the other simply run a new brown wire over to the bad side PIECE OF CAKE 

 John T