One dim parking light?

[rymanrph]

I went through and worked on all my front end lights today cleaning grounds, etc. to get the headlights, parking lights and marker lights to work.

I was able to get everything to light, but one parking light is very dim. I put a new bulb in it, cleaned the contacts and used some dielectric grease. Both headlights and marker lights are fine; the other parking light is good too, but the passenger parking lamp looks barely lit. Any ideas?

 

[n00blike]

try swapping bulbs with a known working one. To see if it is the connector. Then inspect the connector if the light is still dim with a know good bulb. I had a parking lamp that had a partially melted connector which caused a dim light.

Also if you have a voltmeter you could measure the voltages.

 

[TrailBeast]

Take a peice of wire, ground one end to the battery negative and touch the other end to the bulb base while it's in the socket and turned on. (The bulb base, and not the socket metal)
If it gets brighter then you know there is a ground issue.
If it doesn't, then you know it has low voltage.

On some of these old lights I have found that the metal housing the bulb socket is crimped into has a crappy ground to the socket. (I guess corrosion gets between the metals)

 

[RedFish]

Ground path for these bulbs begins where the metal base of the bulb meets the socket. If the inside of the bulb socket is crusty there may be only tiny contacts at the keeper on the bulb base. Spring tension and vibration would keep a current path there.
You didn't say what model so I'll add this... A pot metal fixture will have the bulb socket crimped into it. I've seen the ground path lost there. Previously someone had melted a lot of solder in around the crimp,,, didn't help. A tiny sheet metal screw though to connect both parts cured it.

 

[toolmanmike]

The other guys are spot on with a ground problem. I had one on my Dart that was dim and the dash indicator would glow dim with the headlights on. I cleaned the socket and the hole in the light but no good. I cleaned a spot on the outside of the socket and soldered a wire onto it with a spade terminal grounded to the bumper bracket and it fixed the problem. tmm

 

[nm9stheham]

Probably a ground issue as said. You also get this with mismatched bulbs and an old electrical system, so check the bulbs PN's side to side. The bulb with the lower resistance can draw more current and starve the other. This shouldn't happen but with older light switches and connectors with some built up resistance and corrosion, it can happen.

 

[67Dart273]

The theory of wiring is easy. It's the hardware that's "hard" LOL

 

[TrailBeast]

Ground path for these bulbs begins where the metal base of the bulb meets the socket. If the inside of the bulb socket is crusty there may be only tiny contacts at the keeper on the bulb base. Spring tension and vibration would keep a current path there.
You didn't say what model so I'll add this... A pot metal fixture will have the bulb socket crimped into it. I've seen the ground path lost there. Previously someone had melted a lot of solder in around the crimp,,, didn't help. A tiny sheet metal screw though to connect both parts cured it.[/QUOTE]

Yep, that was my point and probably a little better explanation.

 

[rymanrph]

Thanks for the input everyone. I'll have to check it out next time I'm home.

 

[nm9stheham]

The theory of wiring is easy. It's the hardware that's "hard" LOL

So true....experience picks up where theory ends...

 

[rymanrph]

I cleaned the housing as best as I could and re-installed the new bulb - same results. Then I put the new bulb in the housing that was bright and it looked like the other dim side. So I put the old bright bulb in the dim passenger side and they evened out.

 

[johnnycuda]

ground wire

 

[67Dart273]

Sure seems like it.

Turn park lights on. Securely clip one lead of your meter to a GOOD battery ground point.

"Stab" the other probe directly into the socket shell of each park light. Set the meter down for low voltage measurements. I'd bet one or the other will read "above ground" by some voltage.

If that is not it, then it almost has to be one of two things:

Poor connection from the contact button on the bulb to the park power wire in the dim side

Or poor connection where the two park light wires splice into the single power feed in the harness......Not sure where that is, somewhere up where the harness comes "out of" the rad support area, I'd guess.

 

[Inertia]

Check the bulb #s,, I found 1 bulb being an 1157,, and the other 1034/?,, have diff wattage,, and thus one is brighter, you putting in that bulb,, matched the wattages..

 

[rymanrph]

Both bulbs are 1157A's so that's not it, but how bright are they supposed to be? Do they appear too dim in the above picture? They aren't nearly as dim as the passenger side was before, but the old bulb in the driver side was brighter than both appear now. At least they both appear to be roughly the same brightness now.

 

[67Dart273]

You should be able to take two new bulbs and do the following:

Put a working old bulb in either side

Take your two new bulbs and try them in the opposite side. Both should be "apparently" the same brightness.

Switch your old bulb to the opposite side. Again try both new bulbs in the remaining side.

Now install both new bulbs one in each side. Still a problem? If so It HAS to be

socket grounding

wire pigtail contact

splice in the harness.

I assume you are comparing brightness with the lenses OFF. One lens darker? From sun, fading, etc?

 

[nm9stheham]

Or one bulb was reversed.

1157's are dual filament bulbs and must be installed with the correct orientation in the sockets, but can be forced in 180 degrees out if you do not pay attention. If one is backwards then its brighter blinker filament will be connected as the parking light on that side and the parking lamp intensities will be mismatched.

Note that the bayonet pins on either side of the bulb base are at different distances from the base; the sockets will have the same different locations for the bayonet pins so you should not be able to reverse the bulbs. But, sometimes the sockets get spread a bit an it is harder to tell if you have them inserted the right way, or backwards.

Try the blinkers as well as the parking lights. If both parking lights are the same intensity, and both blinkers are the same brigthness (and are noticably brighter than the parking lights), then you have both bulbs in the sockets correctly.

 

[67Dart273]

Or one bulb was reversed.

1157's are dual filament bulbs and must be installed with the correct orientation in the sockets, but can be forced in 180 degrees out if you do not pay attention. If one is backwards then its brighter blinker filament will be connected as the parking light on that side and the parking lamp intensities will be mismatched.

This is a very good point and it's also possible that someone trying to do some wiring repair reversed the park and signal conductors on one socket.

 

[nm9stheham]

And IMO, the parking light intensities look decent to me in the pix, especially if the car is just on battery; they will brighten a bit more when the car is running.