Dim Lights

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charger426

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So I've had some problems with my lights on my 71 Swinger being super dim. I fixed the problem with my headlights being too dim by chaining to LEDs. Thinking I could just switch to LEDs in the back and "solve" that problem I don't even have enough power to get the reverse light LEDs to kick on and the brake/parking lights are SUPER dim. Anyone else have a similar problem and a way to fix it?
 
It could very well be a ground issue. Does it crank strong? Can you disconnect battery while its running?
 
Motor wise thing is great cranks strong. Haven't tried taking the neg of the battery...shouldn't that kill the car?
 
Don't disconnect the battery with the engine running. It will prove nothing, and could damage the electrical system.
Time to break out the voltmeter and find out where the voltage drop is. A good place to start is the bulkhead connector.
 
So used some contact cleaner on the sockets and used dielectric grease on the bulbs. I noticed a rather big improvement. With that said my LEDs still didn't work and my front parking lights looked brighter.
 
Have you bypassed your amp gage, and run your alternator hot directly back to the battery? This eliminates,a common trouble prone and (fire hazard) area.
 
Nope haven't touched the wireing yet. With that said the previous owner hacked up all the wires to the stock stereo. But I don't think that would cause dim tail lights.
 
Here's the point that you are missing... Your cars entire electrical system is weak. Dim lighting is the only visual indication ( volt meter for dummies LOL ). Don't take that personally 'cause you're just one of the crowd of owners who don't or didn't realize how much better everything about the car could work if it had the full 12 volts required.
So replacing every light bulb in/on it with LEDs wont get better start, run, fuel mileage, wipers, etc...
This forum can brighten/enlighten the space between our ears.
The madelectrical bulkhead/amp gauge bypass isn't required to fix it either. All that really does is move the factory engineered point of failure to some other locations under the dash. It all worked just fine when it was new so with proper repairs it can again .
 
So rather then saying I'm a dummy why don't you tell me what is wrong/help. Being helpful is what this forum should be about not just saying this is a place to help people.
 
Could it just be the alternator rated to low.50 amp vs 100 ? i bet your dim lights is happening at idle.
 
Hey Charger 426, Had,same issue,
1. did you have car dissassembled for repaint/restoration? If so, ground points may be covered with paint .You need bare metal for a good grounding point.
2. MoparMat2000's point is valid. Great way to eliminate this problem prone factory harness problem
3. Redfish is also correct. The wiring works fine when re assembled to factory specs with good clean connections and connectors.
4. Start with the simple stuff first, replace each bulb,especially the 1157's as shorted filiments can no end of electrical havoc.
5.Don't assume anything is functioning correctly even if it is a new component. Even new or re-manufactured components can be faulty.
6. Alternator and wiring been replaced/new?
7. Ignition new/replaced ?
8.You mentioned wiring modified for an aftermarket stereo. Like I said before, look for the simple ,obvious stuff first. Check out the modifications to the wiring harness used to install the aftermarket stereo and return them to the factory configuration.
9. Start the car, and remove the accessory fuse .

I don't profess to be an expert but I do have 23 yrs experience in the electrical/electronics field as a technician.

I don't have a lot of details to work with here so I hope this helps some.

Good luck with it.
 
charger426 said:
So rather then saying I'm a dummy why don't you tell me what is wrong/help. Being helpful is what this forum should be about not just saying this is a place to help people.
Click to expand...

Since this forum archives 27262524 previous threads covering this topic, the answers you need are already here.
 
charger426 said:
Nope haven't touched the wireing yet. With that said the previous owner hacked up all the wires to the stock stereo. But I don't think that would cause dim tail lights.
Click to expand...
What everyone is trying to explain is that the wiring and connections ARE the very likley problem, and this is based on literally thousands of similar cases in the past. That is what you need to tackle in this case and cleaning/checking grounds is part of that; there is usually no 'just do this' solution for dim lights.

The reason is that when current flows through wires and connections, there are tiny amount of what is called resistance in each. If the connections get corroded or dirty, then the connection's resistance increases and the current flowing through them causes a voltage drop at each dirty/corroded connection. At the far end, at the lights, you end up with much less voltage than originally when everything was new.

The current from the alternator to the tailights has to flow through at least 8 connections on the 12v circuit, plus more connections in the ground circuit via the chassis, plus a switch contact in the headlight switch. Any of these can cause the problem and it is common for several of them to have minor voltage drops that add up.

Get yourself a voltmeter (you truly need one in your tool box for these cars when the wiring gets old) and check the voltage at the contacts of the lights that are dim and you find that the voltage to chassis ground at the dim light is much less than 12v. If low, then you check voltage at each connection from the light back working your way back to the power source (the alternator for a running car or battery is not running) and find where there are large voltage drops across a conneciton or switch.

Also, check the health of your alternator to make sure it is putting out the correct voltage. Measure the voltage across the battery terminals with the car warmed up and the car at fast idle; it should be 13.7-14.3 volts. If lower, that is also contributing to the dim lights.

Does the ammeter work in this car?
 
The ammeter does work and does tend to say in the charge side rather than the middle like my 5th ave. To be honest for all i know everything could be fine and things are just dimmer than my 5A and other old mopars. Once I cleaned out the sockets and put some dielectric grease on the bulbs things did get brighter.

Just didn't know if there was a typical go to problem spot on these dart and it sounds like its the bulkhead connecter. So next stop is checking the voltage at the battery while running and then at the sockets. Thank you all for your help over the last few posts, this is what I was looking for!
 
Well, the tailights don't go through the bulkhead connector. The power sourced from the alternator or battery does go through there, as well as all front lighting.

The ammeter being + or - depends on the alternator and its behavior AND the the battery condition (as well as the particualr ammeter's sensitivity); the ammeter is used to show the current flowing in and out of the battery (except for the starter solenoid and starter current from the battery).

You will be doing yourself a big favor to get that voltmeter and make some measurements; looking forward to seeing that info. We can be a lot more focused with advice if we have some solid data to go on. Without that, it is just general adivce to 'check and clean, check and clean'.....
 
Funny you should mention the front lighting. My front parking lights being so much brighter than the my tail lights is part of the reason I starting looking into this. But agreed checking some voltage will be the next move.
 
So I drove the dart last night with my radar detector plugged into the cigaret lighter so I could see my voltage as I drove. After the car warmed up I averaged about 15.5 while driving and 10.5 while sitting at a light in gear. I had the heat on high and don't have a radio in the car. I'm tempted to say this is a voltage regulator problem but want to hear what you guys think before I throw a part at the problem. I do not know the age of the battery but it does look newish and I try to keep a battery tender on it.
 
Well, at least it is A voltmeter lol. The cig lighter is connected to a fuse that also supplies power through the headlights switch for the pakring and tailights. So that matches up with your dim lights issue at idle. It might be a regulator but a regulator issue would not likley cause both such a high voltage AND such a low voltage. The fact that you can see 15.5 volts means that the regulator CAN command the alternator to put out a pretty high voltage and the associated current, so that says the VR can do its job.

What is more likely is that you have some siginificant voltage drops in the wiring. This might not seem rational to cause the high voltage you see but here is the reason: The regulator looks at what ever voltage is coming back to it from the ignition swith and harness, and adjusts what it is commanding to the alternator (by adjusting the field current to the alternator, which is what the VR controls). If it sees too high a voltage, it turns the alternator down. If it see to low a voltage, it turns the regulator up to compensate.

It is common in these cars to have excess voltage drops in the wiring as everyone has been discussing and the VR will see too low a voltage; it will then command the alternator to 'turn up'. At higher RPM's, when the alternator can actually do this, you will see excessively high voltage like your 15.5v. At idle, the alternator can't put out such a high voltage, even if the VR is putting all the field current into the alternator that it can; the alternator just can't put out the poop the the VR is 'telling' it to do at low RPM's. So the alternator voltage will be low (normal) and the readings in the rest of the car will be even lower due to the voltage drops we have all been going on about.

A bad VR will most likley fail so as to produce low or high voltage at all RPM's high, all the time, not high and low like you have. You don't seem to want to tackle the wiring and that is understood; it is a lot of work, buuuuut......it is pretty plain that this is the most likley problem and is a very common one. If you can afford a radar detector, you can surely afford a simple voltmeter, which will give you the best tool to tackle this.... costs about the same as a VR.

"Luuuuke....listen to the Force......it wants you to fix the wiring......" :rolleyes:
 
Not sure why your comments about what i can/can't afford are oh so needed. But yes you right I would rather not start ripping out wiring because as you said it is a pain. With that said if that is the fix I would be willing to do it. Was just hopping for a easier fix before buying all new wires and re-doing the whole car.

From my car audio background people use to always talk about doing the "big 3" upgrade to help cars with weak charging systems that couldn't hold voltage. It changes the battery ground to chassis wire, the chassis to engine block wire, and the alternator plus to battery plus wire (see link below for some more details). Do you think this would be a worth wild upgrade before tearing apart the wiring in the car? I know it would be just a band-aid in comparison to redoing the whole wiring in the car but I sure as heck would be A LOT easy.

http://www.crutchfield.com/S-PS8BvYq4tXC/learn/learningcenter/car/stereo_power_ups.html
 
There's a heavy gauge wire going to the starter so a good battery and a starter that spins great is not a clue. The entire remainder of the vehicle operates on a much smaller wire. This wire goes through a service disconnect connector and a fusible link just before the bulkhead connector. Once the wire gets past all these common failure points and to the inside of the cabin, it branches from a welded splice to several more connections such as the fuse box, ignition switch, etc...
so theoretically, if the headlight circuit alone is weak, the problem is likely at the headlight switch. If all the branch circuits are weak the fault is back at the root.
All of that is about the positive side of the system. The negative side could be the fault location. It is much simpler since most everything is chassis grounded. That means the cars metal is a ground wire. The negative or ground wire on the battery goes to the engine and is surely grounding the starter. Because the engine is pretty well isolated from the rest of the cars metal, by rubber mounts, a small ground jumper wire is attached from the back of the engine to the firewall. There are a few more of these small ground wires in various locations that differ with year model. Most of those rely on the main one from engine block to firewall.
As for whether the voltage regulator is doing its job or not, I think its doing as well as can be expected. The longer you sit and idle and loosing stored power in the battery the harder the alternator will work to build it back again. This only shortens the life of the battery.
So here I've typed out a whole bunch of crap that should help. If you decide to just take it to your local garage and let them fix it, I would rather not know.
Cheers
 
1. You need to check the ground for the rear lights. Turn, park, and reverse ground is the light housing mount studs to body. Bad or poor ground = dim lights. Clean the outside metal surface of the bulb receptacles and temp jump a new ground wire from a good body ground point in the trunk area (trunk lock latch bolt etc) If lights are brighter that is the problem. I always solder a ground a dedicated ground for the rear turn/brake/park lights in the rear. The front headlight/turn/park have dedicated ground wires bolted to the front radiator support area.
2. Left side drivers kick panel removed and access to rear light harness is a 6 or 8 wire rectangular connector. turn/brake/tail/reverse/gas gauge etc. Check for corroded contacts and you can check for continuity to the rear if need be.
3. cig lighter is not a good place to check voltage. Most lighter are corroded and use the ashtray hinge point as a ground path.
4. DC blower motors pull a lot of amps so your 10.5 at idle where you were reading voltage is not uncommon.
 
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