Patrick - LED Taillight problems

[patrickt]

I think I might know what it is, but I want to be absolutely sure, that with Fuse #6 out of the car, and both fast blow fuses in, with the key on and the turn signal on can you see if the panel lights on your gauges are blinking? I understand that all four corners of the car are blinking.

[Xack]

Originally Posted by DanEC

I just had a thought (no snide remarks please) - the people who have chimed in on this thread and said LEDs work in their tail lights in ERAs, have the round tail light option which I believe uses 4 bulbs instead of one being a reflector. Kevens2 has round lights, I know Patrick does, I think Large Arbor does. I have the rectangular tail lights with one bulb each.

Possibly, it takes the 4 LED lights together with the front ones to create the resistence properties necessary for everything to work. Without my parking lights on there just isn't enough load in the system and something is going wrong. When I turn on my parking lights the extra load on the system brings everything on and it works fine.

Is there anyone out there who hasn't given up on this thread already, with rectangular lights and had sucess with LEDs in the tail lights.

Patrick and Dan,
Dan, You did mention that you have 4 blinker relays? or 2? or 1? In most cases the blinker has at least 3 incandescent lights in a normal circuit. Front, Rear and the dash indicator. If you have a blinker relay for each light, the problem may be that each relay only has one LED for it's load. It's not easy to tell from the discussion. Most LED distributors sell loads for the LED blinkers to operate correctly. Do you have something like this installed? However it seems this is the opposite problem... Normally the load is needed to get the relay to blink. All your lights are blinking !! ??? I am cornfused!

[DanEC]

Originally Posted by patrickt

I think I might know what it is, but I want to be absolutely sure, that with Fuse #6 out of the car, and both fast blow fuses in, with the key on and the turn signal on can you see if the panel lights on your gauges are blinking? I understand that all four corners of the car are blinking.

Yes - with #6 pulled.

But I've know for some time that the parking light circuit is somehow getting energized by the flasher circuit when the parking light switch is off. The dash lighting controller is pulling power from the common termination at fuse 6 with the parking lights.

There's not many places the parking lights could be getting power from - Dimmr relay to headlights to light switch - something at the ignition switch?? Or the brake light switch could be feeding power from the turn signal switch through fuse 5 and then fuse 4 to the flasher unit. It seems this would be showing up with regular 1157 bulbs in place however.

I'm still kind of on the theory of some sort of internal cross-talk inside the LEDs because of low load.

[patrickt]

Originally Posted by DanEC

Yes - with #6 pulled.

But I've know for some time that the parking light circuit is somehow getting energized by the flasher circuit when the parking light switch is off. The dash lighting controller is pulling power from the common termination at fuse 6 with the parking lights.

We're almost there. Leave Fuse #6 out of the car from this point on. There are three wires on the driver's side terminal of the empty fuse holder #6. One of those wires goes to the front two lights, another goes to the rear two lights, the third goes to your panel lights. You must separate those three wires and then turn the key on, put your turn signal on, and then tell me which one of those three wires is getting a flashing 12 volts. That will be the circuit that is faulting over to the flasher current. We will then trace that circuit and find the problem.

[DanEC]

I'm going to have to think about that one. I'm not too inclined to start pulling Bob's nice soldered and crimped connections apart especially at the crowded fuse panel connections. I could eventually really have a problem then. I may have to look at pulling some plugs apart to isolate the circuits.

All for tonight.

[patrickt]

Originally Posted by DanEC

I'm going to have to think about that one. I'm not too inclined to start pulling Bob's nice soldered and crimped connections apart especially at the crowded fuse panel connections. I could eventually really have a problem then. I may have to look at pulling some plugs apart to isolate the circuits.

All for tonight.

That's understandable. Here's a lower impact method: On the driver's side light fixture there are red wires running to that light. One is a source feed, the other runs to the license place light and the other tail light. Mark each one of those wires so you know which goes to which, then cut them and tape off all ends. See if your turn signals now function properly. If they do, one of those cut ends will be flashing 12v and that wire leads to the fault. In fact, one of those cut ends will be flashing regardless, and that wire points to the fault.

[DanEC]

I'm not in the mood to start cutting up my wiring just to make LEDs work. I have some other ideas to try. With flashers on and parking lights off, I'm going to pull both red leads to the rear tail lights and see which side is hot (or if both are). I suspect it's going to be the bulb side, bleeding over from the flasher circuit - otherwise why would the license plate and dash lights be blinking and not just lit up.

I think I will pick up a 1157 socket and temp wire it to the pass side tail light flasher circuit with a 1157 bulb and see if the extra load makes any difference.

Then look at the major harness connection plugs - especially #27. When assembling the car I had a parking light problem at the front and finally found two wires mispositioned when the harness was assembled. Reversing those wires to match the wiring diagram straightened out all my lighting problems. But - maybe there is still something out of whack there.

I can't see how the dash light circuit could be backfeeding anything as it's basically a dead end circuit and supposedly doesn't run through any harness connections so I think I can ignore it.

See what happens.

[patrickt]

Originally Posted by DanEC

Then look at the major harness connection plugs - especially #27. When assembling the car I had a parking light problem at the front and finally found two wires mispositioned when the harness was assembled. Reversing those wires to match the wiring diagram straightened out all my lighting problems. But - maybe there is still something out of whack there.

I can't see how the dash light circuit could be backfeeding anything as it's basically a dead end circuit and supposedly doesn't run through any harness connections so I think I can ignore it.

Reversed pins will do it... for sure. The reason we "walk back" from the end of the circuit (the end of the circuit is at the pulled fuse), and seemingly take unnecessary steps, is that the underlying portions of the circuit are not absolutely distinct. For instance, the panel lights are on the same line as one of the front parking lights, but not the other.

But you know that you're getting a flashing 12v at fuse #6 with the fuse out. That should never happen. That's the fault, and it's traceable. I think it's going to end up being a faulty rear fixture, or a misaligned pin alignment in a plug.

[Xack]

Originally Posted by DanEC

I'm not in the mood to start cutting up my wiring just to make LEDs work. I have some other ideas to try. With flashers on and parking lights off, I'm going to pull both red leads to the rear tail lights and see which side is hot (or if both are). I suspect it's going to be the bulb side, bleeding over from the flasher circuit - otherwise why would the license plate and dash lights be blinking and not just lit up.

I think I will pick up a 1157 socket and temp wire it to the pass side tail light flasher circuit with a 1157 bulb and see if the extra load makes any difference.

Then look at the major harness connection plugs - especially #27. When assembling the car I had a parking light problem at the front and finally found two wires mispositioned when the harness was assembled. Reversing those wires to match the wiring diagram straightened out all my lighting problems. But - maybe there is still something out of whack there.

I can't see how the dash light circuit could be backfeeding anything as it's basically a dead end circuit and supposedly doesn't run through any harness connections so I think I can ignore it.

See what happens.

For your peace of mind and sanity, you should troubleshoot this to figure it out. In the end you'll fix something which could possibly cause you issues later or cause something not to work the way it should as you drive your car.

Quite possibly there is something shorted or connected wrongly. The connectors should be invistigated for pins folded over or things just connected up wrong or switched. Assume nothing, verify everything. Divide and conquer.

I wish you well in this and I'm following.
Xack

[patrickt]

The beauty of this problem is that it is not intermittent. It happens every time. That makes it soooooooo much easier to trace. A few years ago, I had an intermittent problem on my ERA. To diagnose it, I had little 12v indicator lights strung up all over the circuit and taped to the dash. When the problem occurred, I quickly looked at the dash to see what lights were lit and what weren't. That told me where the problem was (and where it wasn't), but, boy, that was a PITA.

[kevins2]

Dan,

When I wired my car initially, not everything worked properly and I discovered that two pins (one on each connector) on the wire harness were not seated properly. So, when I connected them, the pin simply backed out of the connector and wasn't making a connection. It is really easy to check if you haven't already. In my case, as I was checking all the connections, I heard the two distinctive "clicks" as the pins locked into place. I think it is best to check these connections with the connectors unplugged. My apologies if this has already been addressed - this has become quite a long thread!

Good luck tracking this down.

Kevin

[DanEC]

Originally Posted by kevins2

Dan,

When I wired my car initially, not everything worked properly and I discovered that two pins (one on each connector) on the wire harness were not seated properly. So, when I connected them, the pin simply backed out of the connector and wasn't making a connection. It is really easy to check if you haven't already. In my case, as I was checking all the connections, I heard the two distinctive "clicks" as the pins locked into place. I think it is best to check these connections with the connectors unplugged. My apologies if this has already been addressed - this has become quite a long thread!

Good luck tracking this down.

Kevin

Hey Kevin - yes, this is a long thread. I think I should re-title it; "How to create a problem where none existed before and successfully fix it in 12 pages or less".

That's my fall back plan - I don't have to run LEDs. I can be satisfied with a 100% functioning filiment light system. I am going to look over the connection blocks closely again. I think I checked all the pins at the time of assembly but it's been a couple of years. And also match up the wires on each side, although I spent a week doing that during installation.

I guess another fall back is just to drive with my lights on all the time. I considered that but I'm afraid I would forget to turn them on sometime and the first time I signaled for a turn everyone would think I was declaring an emergency.

[DanEC]

Originally Posted by Xack

For your peace of mind and sanity, you should troubleshoot this to figure it out. In the end you'll fix something which could possibly cause you issues later or cause something not to work the way it should as you drive your car.

Quite possibly there is something shorted or connected wrongly. The connectors should be invistigated for pins folded over or things just connected up wrong or switched. Assume nothing, verify everything. Divide and conquer.

I wish you well in this and I'm following.
Xack

I'm still thinking it's a load issue, either from the Pilot bulbs or my flasher unit. I'm not going to cut the harness. Anytime I see an old car with a splice in it I think - there's another car some Bubba butchered up. But, I'll hunt and peck around some more and see what I can turn up. Thanks

[kevins2]

Originally Posted by DanEC

Hey Kevin - yes, this is a long thread. I think I should re-title it; "How to create a problem where none existed before and successfully fix it in 12 pages or less".

I hear you, but you've learned a lot from this process and I believe Patrick is designing your honorary Electrical Engineer plaque as we speak.

As for your comments about driving with your lights on, I always drive with mine on but, as you stated, I've forgotten a few times and turned them on in progress. So far, I haven't left them on and run down the battery. Probably because I always look back at the car whenever I'm walking away from it...

I hope you get the satisfaction of figuring this out.

Kevin

[patrickt]

Dan, you might want to try this: Put your old incandescent bulbs in that you were reasonably happy with. Pull your Fuse #6 and put a VOM on the driver's side of the fuse receptacle. Then turn your key on and put your turn signals on. See how much, if any, your VOM indicates. Then do the same with the LEDs and compare.

[DanEC]

I tried some of my above mentioned testing this afternoon and came up with some interesting results.

1. Disconnected both red (parking light) leads at the rear tail lights. Turned on the key and the flasher. Tested both red leads for any sign of voltage and came up with 0 volts.

Stuck the VOM probe on the tail light socket for the red wire and got a significant fluctuating voltage at both of them (fluctuation with flashing). To me that is pretty convincing that the power to the parking lights (with lights off) is coming through the bulbs.

Installed my 2357 bulbs and repeated the test and got 0 voltage at the red wire socket on the bulb holder.

2. Next I took one of the pilot bulbs and hooked it up to my battery charger (putting out about 10 volts - thought they would be higher) and with a VOM checked voltage at the other contact.

With voltage to the flasher contact I got bleed over of .46 Volts at the parking light circuit. With voltage on the parking light circuit I got voltage leaking over to the flasher lead of 6.26 volbs.

I pulled one of the SuperbrightLEDs out of my GTX and tested it. Power to the flasher contact I got 0 volts at the parking light contact. Power to the parking light contact I got 3.64 volts at the flasher contact.

So, in conclusion I'm pretty sure the Pilot lamps are junk and anybody reading this shouldn't waste money on them. Still doesn't completely explain my problems with the SuperbrightLEDs and maybe someday I will pull them out of my GTX and go through some checks. But they seem to also have some leak over between circuits and I don't know why this affects my car more than some others. Re-installed my 2357 bulbs and buttoned everything up for now.

Thanks for all the help and support.

[patrickt]

Alright... eventually you'll return to the LEDs in search of the fix -- that's just your nature; you may delay it, but you'll not dismiss it in its entirety. You can't, and you know you can't.

[Dirty Harry]

Having a red car, I've always wanted a little brighter lights to the rear, in order to be more attention-getting. After I read post #75 I went to the local parts store and bought the red Pilot bulbs. I haven't been out to the garage to give them a try yet, but now I'm a little apprehensive.

We'll see what happens. Hopefully, I can give them a "glowing" report. Good discussion, guys.

[DanEC]

Originally Posted by Dirty Harry

Having a red car, I've always wanted a little brighter lights to the rear, in order to be more attention-getting. After I read post #75 I went to the local parts store and bought the red Pilot bulbs. I haven't been out to the garage to give them a try yet, but now I'm a little apprehensive.

We'll see what happens. Hopefully, I can give them a "glowing" report. Good discussion, guys.

It's all very strange. I put a set of Pilot bulbs in my old Corvette and they do seem to work OK in it. I'm tempted to remove one and see if it also bleeds power from one circuit (contact) to the other.

The internal circuitry of these things is a bit unknown - someone said they work like a diode. I noticed in my testing with a battery charger and VOM that they will only flow current in one direction so that may well be. I also know that with the trailer relay in the ERA we are not getting a full 12 volts on the flasher circuit at the bulbs. That may or not be an issue because when a flasher relay is functioning I doubt we are getting a full 12 volts either. It may be that they need a higher voltage than my car is delivering through the flasher and trailer relayto function properly. I'm not enough of a circuits guy to fully understand the problem.

Hope they work for you - I regret my recommendations for the Pilot bulbs now as now I don't think the quality is there.

[kevins2]

Hi Dan,

Since you have both the Pilots and SuperBrights it would be good to know which is brighter, if you can see a difference.

Kevin