Volt Meter ???

trying to figure out why my left rear directional is not working. tracked it to a splice under the hood. when I disconnect the joint and put the meter on the directional side of the connection I get volts (blinking). when I connect the joint, I get NOTHING on the light side of the splice. Short in wire between joint and light??? I sanded the connectors and still nothing..... Really confused??

 

Short at the light fixture?

 

IDK yet. would a short show up as no voltage at the connection??

 

Bad grounds and such-like at the taillight socket can result in voltage backfeeds through the bulb's double filaments, with all kinds of weird effects.

 

going to check it section by section tomorrow. ran out of time today...

 

I suspect there is a short to ground in this section of your wiring. Remove the bulb and then check for shorts to ground.

 

The bulb sockets are notorious for getting corroded inside and not allowing either the hot center wire to make contact to the bulb or the surrounding body to make a ground to the bulb body............get an ohm meter and check across all points.......a 12 gu shotgun barrel cleaning brush works to clean that corrosion out of the sockets..........once a good contact is made a product like a Dielectric Silicone Grease ......can be used to coat the bulb and keep moisture & corrosion out.

 

A test light would be far better to use for this purpose vice volt meter or ohm meter. Just my 40 plus years of experience talking.

 

Lots of checking methods to get there...............an ohm meter acting as a continuity checker is used to determine if an electrical path can be established between two points; that is if an electrical circuit can be made.

Bad ground frame connections are always at risk when trouble shooting 12v issues on old vehicles............

 

this thing is baffling sometimes. standard stock male/female bullet connector (new wiring harness as of 12-15 years ago) Had power at the female side from the directional but no power on the male side when I plugged it in. cleaned and lightly sanded the connectors as best I could and still nothing. checked the wire to the stop light and it was not shorted. replaced the connection and the light started working. No clue how a clean bullet connection was not working...…

HOWEVER, the left rear brake light is not coming on. need to figure out the wiring for the brakes....

 

Played with it a bit more .looks like the internals on the Spartan are the issue. Brakes and turn are intermittent depending on position of turn lever. Guess I will be in the market for a used one to rebuild because from what I see there are no original equipment replacements. Don't want aftermarket

 

I'm better at taking apart than putting back together

 

When I start trouble shooting taillights/turn signals I check grounds first, clean all surfaces in ground connections and use dielectric grease as Tarry mentioned. Then you can test with test light/VOM hot wires to ground with a known good ground, about 50% of the time the ground is the problem, so you have fixed it. I recommend dielectric grease /on all electrical connections. If establishing the ground doesn't fix the problem I start at the source and check both sides of every connection/splice and peel off any electrical tape that is not original, to check voltage and/or continuity. I use a copper tubing brush, aforementioned battery terminal brush or shotgun bore brush to clean the lamp socket. If all else fails I check the lamp visually and for continuity and to ensure the correct lamp has been installed, Don't jump around , trace circuits from source to load I;e: light, lighter, windshield wiper etc. Without a ground you will never be able to test a circuit. Loss of voltage indicates a open circuit, usually caused by broken or corroded wiring, a short circuit results in blown fuses or melted wiring usually caused by chaffed or failed insulation allowing a 12 volt source reaching a ground, Good luck!

 

this thing has gremlins…. but I have killed a lot of them in the last week. took the Spartan completely apart. one of the tiny springs was broken which is why it had intermittent lights. All depended on where the contact plate happened to sit when moved. I was lucky that I had some scrap Spartan parts for some reason and just happened to have one of the springs. Cleaned all the contacts and replaced the spring and all the lights are working again.

one additional question, should the front running lights stay on when the headlights are on?