Road Runner Nest

Something most of us experience in our old mopars is weak light output from the tail lamps, and/or dimming and flickering of other lamps when our turn signals are flashing.

Blame it on the inherently weak out put of our electrical systems at idle and 40 year old wire harnesses.

Anyway, I got tired of dealing with the symptoms and figured that I'd experiment with drop in LED lamps to replace the 1157 bulbs out back.

If you've ever shopped for these, you know there are many configurations, and some are quite expensive.

Biggest problem is the reflector and lens optics in the tail lamps are design for the 1157 incandecent bulb. Light output from LEDs is quite different. Most of the drop-in LED replacements you'll find at the auto parts stores will yield a dot of light in the middle of the lamp.

After doing my homework, I discovered this type would most closely emulate the 1157 bulb:


I purchased a pair off ebay with the intent of installing them on just one side for comparison. They attached pictures show the results. I'll let you guys guess which side has the LEDs. I've now got a set for the other side on order. Here's the auction:
http://www.ebay.com/itm/150638784034?ss ... 1423.l2649

This vendor is by no means the only one. He just happened to have the best price and feedback rating. YMMV.

My current flasher seems to be working okay with them. PO may have already converted it to a new electronic one. I still need to take a test drive to see if it's lowered my amp draw enough to reduce or eliminate the flickering at idle. Only time will tell how well they hold-up.

They look really nice.
Can you let me know if they are brighter in daylight use too.
Anyone else using these?

These have pretty much the same light output. I stayed pretty conservative.

You can get some with more LEDs, but then you can be glaring in the face of following vehicles. That can be pretty annoying.

I'll try to get some daylight shots today.

i had weak lights and it turned out to be a bad ground. They changed the washer to a crown washer and now all my lights are plenty bright enough.

In my case, the light output was okay. My rear wire harness is an original though, so I'm sure it's lost some current carrying capacity. I did freshen up the ground connections back in the summer when I had to replace the bumper.

At night with the headlights on at idle, everything would dim as the turn signal cycled. It's just low alternator output. Not sure what the amp draw is with the LEDs, but it is certainly going to be lower. I probably won't notice much difference in that department until I replace the other side.

I might ultimately do the front lamps too. One step at a time.

On the electrical systems for our cars, there is a design flaw with mopar using the indash amp meter. I would suggest reading some of the tech articles at Allpar which explain and address these issues.

Head lights are already on relays pulling directly off the alternator. That takes the biggest load off the amp gauge and eliminates that voltage drop through the bulkhead connector. At this point, 100% bypassing the amp gauge wouldn't offer much improvement.

http://www.madelectrical.com/electrical ... sing.shtml

Try this then. I stepped up to a high output alternator and a few other upgrades because I hated those dim lights. Works great now, and you might be surprised at just how muchvoltage drops through the connections.
I will be upgrading to LEDs where I can just to keep it as reliable and safe as possible.
obviously good connections are critical. As long as the wiring isn't cracked it should do a pretty good job. Mopar used good copper content wiring these years

I remember my old rr lights dimming at Idle,I plan on upgrading to HID's,they use a ballast and draw less amperage.

mopar71 wrote:I remember my old rr lights dimming at Idle,I plan on upgrading to HID's,they use a ballast and draw less amperage.

Don't get me started on the aftermarket HID crap.