JustEmptyEveryPocket Posted January 26, 2019 Share Posted January 26, 2019 Sorry to start yet another one of these threads, but I am having an issue and need input from people smarter than me: First of all, my truck's interior lights have never worked. When I got the truck the lights were pulled and the plugs were taped off and stuffed down behind the b-pillar trim. I am tired of it being dark in there, and saw some recent threads on this, so I went for it. I pulled some interior lights from an 01 VW golf, like the ones mentioned in THIS thread. They seemed perfect as they had the same functionality and fit into the same hole without mods. So I started trying to wire them in. I bench tested the lights from the battery and found that the red wire was power in, blue was switched ground, and tan was solid ground. Found this by trial and error, while connecting the wires in different configurations and flipping the lens back and forth. Then I got in my truck and put my voltmeter on the three wires. I had 13V in the red wire measured back to the battery. Then I measured from the red wire to the black wire with white tracer and it showed a switched 13V, going to zero every time I actuated the button in the door frame. I assumed the solid black wire was the solid ground. They are wired in as red to red, black w/ tracer to blue, and solid black to tan. After all that, I have no lights. Zero. Nothing in any position. Where did I go wrong here? What should I check/ test next? Side question: while I was fishing around on the driver's side behind the b-pillar I found a wire like the one in the fourth post HERE. What is it? Thanks for any and all help. Link to comment Share on other sites More sharing options...
Pete M Posted January 26, 2019 Share Posted January 26, 2019 my bet is that the long wire is for the cargo light option. I wonder where the other end goes? Link to comment Share on other sites More sharing options...
Ωhm Posted January 26, 2019 Share Posted January 26, 2019 2 hours ago, JustEmptyEveryPocket said: First of all, my truck's interior lights have never worked. So both L/R courtesy lamps don't work either? Link to comment Share on other sites More sharing options...
Pete M Posted January 26, 2019 Share Posted January 26, 2019 did you accidentally blow a fuse? Link to comment Share on other sites More sharing options...
JustEmptyEveryPocket Posted January 27, 2019 Author Share Posted January 27, 2019 Neither side works. I don't think its a fuse because I have backprobed the connectors with my voltmeter a couple of times since wiring it in. Also note I had benched tested both of the lights I installed. They both worked then. Where do the wires from the b-pillar ground at? I can check that end. Link to comment Share on other sites More sharing options...
Ωhm Posted January 27, 2019 Share Posted January 27, 2019 Voltmeters can show good voltage, but they can't determine if current will flow (voltage drop). Can you test the red (12vdc) wire with a test lamp? This will show current (thru the test lamp) can flow to ground. 11 minutes ago, JustEmptyEveryPocket said: Where do the wires from the b-pillar ground at? G102. Bottom of dash, near the steering column, when in the ON position. When in the SW position, ground is provided by each door switch. Also when the headlamp switch is turned to ON will provide a path to ground. Link to comment Share on other sites More sharing options...
JustEmptyEveryPocket Posted January 27, 2019 Author Share Posted January 27, 2019 I ran a test light from the red power wire through a bulb and back to battery ground. Nothing. So I guess this means I am reading 'ghost' voltage? I suck at reading electrical schematics. Can anyone point me to where the red power wire goes? Link to comment Share on other sites More sharing options...
Pete M Posted January 27, 2019 Share Posted January 27, 2019 have you tested the power wire to the ground wire? or just back to the battery each time? Link to comment Share on other sites More sharing options...
Ωhm Posted January 27, 2019 Share Posted January 27, 2019 Since you've lost your courtesy lamps, I think your dropping voltage at the fuse (Dome 10A), IP splice C or the wire in between. 88 Electrical Manual Dome lamp fuse/IP splice C: page 63 IP splice C location (C with a circle around it): page 91 Link to comment Share on other sites More sharing options...
Jeep Driver Posted January 27, 2019 Share Posted January 27, 2019 You should have one power wire and two grounds. One ground switched at dash and doors the other is straight to ground for manual function at the light. You can test grounds with ohm meter. If you have power at the wire end you will get light. Get the ground figured out. Link to comment Share on other sites More sharing options...
JustEmptyEveryPocket Posted January 27, 2019 Author Share Posted January 27, 2019 1 hour ago, Pete M said: have you tested the power wire to the ground wire? or just back to the battery each time? From my first post: I tested power back to the battery. Then I tested from the power wire to each of the ground wires at the b-pillar light. One of them gave me a constant 13V reading, and the other read 13V until I depressed the door switch, then it read nothing. 1 hour ago, Ωhm said: Since you've lost your courtesy lamps, I think your dropping voltage at the fuse (Dome 10A), IP splice C or the wire in between. 88 Electrical Manual Dome lamp fuse/IP splice C: page 63 IP splice C location (C with a circle around it): page 91 I pulled the fuse today and it looked fine, no melting. So now I will try to trace the wires you are pointing me towards. Thanks for your help looking that up. 11 minutes ago, Jeep Driver said: You should have one power wire and two grounds. One ground switched at dash and doors the other is straight to ground for manual function at the light. You can test grounds with ohm meter. If you have power at the wire end you will get light. Get the ground figured out. I did ohm the ground wires measuring back to the battery. I don't remember the numbers exactly, but they were not over 10ohms. Plus, if I ran a test light from the red wire in the b-pillar through a bulb and back to negative on the battery then the bulb should light up. It didn't. This leads me to believe it is not a ground problem. Am I wrong with this idea? Granted, the ground may not be great, but I think there is a larger problem somewhere. Thanks for all the help so far guys. Link to comment Share on other sites More sharing options...
Jeep Driver Posted January 27, 2019 Share Posted January 27, 2019 One wire will have constant power. Use a test light, ground the test light at the pillar, test the power wire, if the test light illuminates, you have 12V at the pillar. Constant ground, make your own new constant ground at the pillar. Switched ground......activated at the head light switch or the door switches. Use ohm meter, switch ground wire should show continuity with door open or with head light switch in the dome light position. If not, you have a ground problem. Touch one lead to the wire and one lead to the new ground you are making at the pillar, needle of ohm meter will move from one extreme to the other, if not, no continuity at ground wire......no ground. Either way, if you have 12V at the pillar you can have manual light after making new ground at the pillar........then work on your door switches which you'll likely have to replace. Link to comment Share on other sites More sharing options...
JustEmptyEveryPocket Posted February 4, 2019 Author Share Posted February 4, 2019 So I finally had some time to get back in and play around with this some more. First of all I took a new reading from the pink w/ black tracer wire that the light plugs into. Went from the wire back to the battery so I had a known good ground. It read 13 WAIT FOR IT mV. That is right, I must have misread it the first time around and I feel like a dumb@ss now. Went back to C118 connector (big thanks to Ohm for the help in reading the schematics) and checked voltage at the pink wire in the connector. It has 12.6V, and yes I tripled check to make sure it read V and NOT mV. Then I thought to measure resistance from the body side of the C118 connector's pink wire and the pink w/ black tracer in the b-pillar. When I hooked my meter on it, it started with a crazy high value (M-ohms), but then slowly came down and ended with 0 ohms. I take that to mean that the wire is complete, ie no breaks in it. Finally, as I was running out of ideas I ran a wire directly from the positive side of the battery to the pink w/ black tracer in the b-pillar to see what would happen. The lights came on! Unfortunately, they did not go off when the door switch was depressed, but stay on constantly in both the "door open" setting and when I switched the lens to "always on". If I switched the lens to the "off" position they went off like normal. So somewhere I am losing power to the wire. And possible have a problem with the door switch. But the power in is the big problem right now. Since I have power at the C118 connector, I need to trace the wire from there. Looking at the diagram on page 62 of the electrical manual Ohm linked, I need to find the "B" splice point. Anyone happen to know where that is? Anything else I need to check? Thanks again for all the help yall. Link to comment Share on other sites More sharing options...
SVPete Posted February 4, 2019 Share Posted February 4, 2019 The headlight switch (dash dimmer switch) isn't rotated all the way is it? Gotta ask. Link to comment Share on other sites More sharing options...
phatton Posted February 4, 2019 Share Posted February 4, 2019 This is a ground operated system. The door switches control the ground feed to the lights. When the door is shut the switch in the door frame pushes in and breaks the ground connection and the pillar lights shut off. When the door is opened the switch pops out closing the ground and the lights come on. The other wire goes controls the ground from the ignition switch to the pillar lights. When the key is turned to on the ground circuit is connected and the pillar lights come on. Pull a door switch. There should be a ground wire on both terminals of the switch, connect that wire coming out of the switch to the pillar light ground wire. Now connect the red harness wire to the red pillar light wire, open the door and the pillar light should come on if it does not the door switch is bad. If the light now stays on when the door is closed, you connected the wrong wire from the door switch to the pillar light If you also want the pillar light to come on when you turn the key on, you need to find the ground wire coming from the key on position of the ignition switch and connect it to the other pillar light ground wire. Hope this helps. Link to comment Share on other sites More sharing options...
Ωhm Posted February 14, 2019 Share Posted February 14, 2019 Went off grid with my visit to The Sunshine State. Voltmeter could still be fooling you (voltage, no current flow). Use a testlight for voltage measurements. Link to comment Share on other sites More sharing options...
rylee144 Posted March 5, 2019 Share Posted March 5, 2019 I finally got around to installing my new b pillar lights. I bought the ones below. I keep blowing the 10 amp fuses and I can't figure out why. Can I just put a bigger fuse in and call it good? Link to comment Share on other sites More sharing options...
Ωhm Posted March 5, 2019 Share Posted March 5, 2019 Was everything just fine before you replaced the B-pillar lamps? Link to comment Share on other sites More sharing options...
rylee144 Posted March 5, 2019 Share Posted March 5, 2019 The bulbs were blown and the lenses were cloudy so I just opted for new one. The door switches still work and I have power. The 10s pop. If i put in a 15 they turn on but if I toggle the light they pop too. Link to comment Share on other sites More sharing options...
Ωhm Posted March 5, 2019 Share Posted March 5, 2019 Check both C277 (connector to B-pillar lamps) for color codes. C277_1 BLK/WHT C277_2 PINK C277_3 BLK Link to comment Share on other sites More sharing options...
JeepSchmidt O'Guinness Posted March 5, 2019 Share Posted March 5, 2019 It shouldn't be tied to the key run/accessory position, but it couldn't hurt to check. Link to comment Share on other sites More sharing options...
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