Electrical problem 1993 Dodge Shadow

[dmeintzer]

I am trying to figure out an electrical problem. When the headlights are off, my turn signals, brake lights and heater work fine. When I turn on my headlights, the extra brake light works but the drvers side rear tail light goes dim and the turn signal will not work. I also have to leave the switch in the far left dome light position or the bright light and turn signal indicators come on and don't function. I have replaced the headlight switch and rear bulb sockets and no luck. I had to disconnect the door dome light switch as well. If I close the door, it still gives me fits with the switch in place. This is driving me nuts. Any help would be great!

[ProTech]

A schematic for your car would come in very handy in a situation like this. As for your problem, this is definitely a shorted wire somewhere. Unfortunately, that's the hard part, as most times the actual short is in the most unlikely or hard to get at place. First of all, I would definitely recommend double checking all the bulbs and sockets, including the front and rear lights and turn signals. I've seen one bad bulb, with a shorted element, cause havoc on entire lighting systems...so check the easy stuff first. Next, start looking for any obvious wiring issues, such as any of the harnesses touching or possibly rubbed through on any of the sheet metal in the trunk area, or underhood area. Check under the dash, too. This will probably take some time. You're going to basically have to trace each and every wire associated with the circuits that are having trouble until you can find the problem.

[dmeintzer]

Thanks. I did check all the wiring under the dash and steering column and they seem to me in tact and in good condition. I did find the headlight relay was bad. I replaced it but still the same problems. I replaced three sockets in the rear. I then noticed the inner two sockets for the tail lights, one has two wires like a single filament bulb and the other has three wires. The two outside lights both have three wires. The only ground I can find in the trunk area is attached to the left rear panel of the truck. No rust and tight. This runs to the tail lights. When the headlights are on it also draws my amp gauge down and it gets worse with the heater on as well. Could too small of a battery be the cause? I noticed the battery case is larger than the battery this guy put in it. Just curious. I will try to get a schematic from the library. Let me know if you have any other suggestions. Thank you so much!

[ProTech]

Usually a 'too small' battery would only affect starting the car, as the alternator takes over the electrical load once the car is fired up. Not to say you don't have a bad alternator, but I really doubt it. Good checks so far, but obviously you'll have to keep looking. If you can get a schematic, that will help greatly!

[dmeintzer]

Thanks again! That gets rid of one possibility. I am going to get a manual tomorrow. I should have done this to begin with! Maybe saved myself some hassle. There must have been an amp in the car because I pulled about 30ft of wire out. None were hooked up but a pain to get out. I will send more questions if that's ok. Do you think the middle tail lights should be two different sockets? I find that hard to believe. Three of four are three wire. What do you think. Thanks for the continued help on this!

[ProTech]

Ask as many questions as you need, we're here to help! And yes, more than likely there are different sockets/bulbs in the middle taillights as they are probably just running light anyway and not the actual brake or turn signal lights. This is the way on most vehicles. Good luck with your repairs.

[dmeintzer]

Thanks,
I really appreciate all the help! I will let you know how it goes once I get the manual.

[dmeintzer]

Got the manual. You were right, great information. I had one more question. When I pull the headlight switch and it's not in the dome light position, there is a click right before the turn signal indicator and high beam indicator illuminate. It sounds like it is in the dash behind the switch. When the headlight switch is in the dome light position, this does not happen and the indicators don't come on. They are normal. I was wondering if you knew what it could possibly be? I will be checking wires tomorrow. Thanks!

[ProTech]

It's probably a relay making the 'clicking' noise, which would be normal.