electrical and ignition LED upgrade tail light issue - '75 2002

[NicholasMav]

I have a "new to me" '75 2002.  I have inherited, through the purchase, a LED tail light upgrade that's giving me a problem.  I did the left (driver) side last night and it worked like a charm.  Much brighter and I'm very happy with it.  This morning I attempted the right (passenger) side and nothing's happening on that side.  The only difference between the two that I could tell was that the passenger side didn't seem to a ground wire coming from the front end, like the driver side did. A friend thought that since the Ground happens before the passenger side, that it shouldn't need it as well.  Thoughts?

 

Any ideas?  Do both need the Ground, if the passenger side is "daisy chained" from the driver's side?   I'm at a loss and am electric stupid.  I'm happy to attach a couple of photos, if needed.

Edited May 24, 2015 by NicholasMav

[ifayeoh]

Yes both need a ground. And ground is ground. They dont have to be ground at same point or connection but some time it helps if convenient.

Brown is typically the dedicated ground.

Edited May 24, 2015 by ifayeoh

[NicholasMav]

Thank you.  The problem is that I don't see a ground wire going to the passenger side.  How do I remedy that?  Again, I'm an idiot when electric is concerned...well, I know enough to not get electrocuted, but the finer points are lost on me.  

[Mike Self]

First of all, a 12v DC system isn't gonna electrocute you unless you poke the wires through your chest to your beating heart--and even then that might not be enough voltage to stop it...

 

To troubleshoot your non-functioning pax side tail light, first try your pax side turn signal, brake light and backup light.  If any or all of them work, then the common ground for the pax side bulb housing is good.  The wire that leads to the center contact on each bulb is the hot lead; the one that leads to the bulb base is the ground.  IIRC all the bulbs on the tail light housing (tail, brake, turn signal, backup) ground through the housing and one brown wire.  Look for it.  If it's become unplugged from the tail light housing, then none of the bulbs will work.

 

If everything but the tail light works, you'll need to look carefully at however the LEDs are connected to the tail light bulb socket.  If nothing is contacting the ground side of the socket, then the LEDs won't light.  Also, LEDs are polarized.  Unlike incandescent bulbs, you must connect the positive lead to the positive terminal, and ground to ground.  LEDs won't work otherwise.  So make sure the lead market + is connected to the center socket terminal, and the one marked - to the side terminal.  

 

Let us know what you find.

 

mike

[NicholasMav]

Here are a couple photos that might help nail down the issue.  The bulbs and the connecting points are a non-factor, as the bulbs are removed and the LED wiring pushed past those points of contact, with exception of the reverse bulb. It wasn't a problem on the driver side at all.

 

In the photo below of the passenger (non-working) side, you'll see all the wiring is plugged directly into the housing coming from the driver's side.  

 

In this photo below of the driver (correctly working) side, you'll see on the far left the Ground (three wires attached to the bolt) coming out of the housing.  The passenger side does NOT have this.  In fact, it seems like the Ground wire stops here and does not continue on to the passenger side.

 

I'm hoping these photos may help in relaying what the issue is.  I may have not accurately explained before...or I'm not understanding the fine people that have chimed in.  My apologies if I'm missing the explanation.

 

Thanks in advance!

NM

[tzei]

Did the passenger side work before that led assembly? Does rh side marker light work okay? Rh rear light and side marker shares ground so check the connector for side marker also - just a thought.

[DRedman]

You only need one ground point as both lights share that ground point by running multiple wires. The drivers side ground has more than one wire on it and one of those should be the ground wire running to the passenger side.  I see that there is a brown wire which may be the wire connected to the drivers side and is going to the LED module and should be adequate unless the wire is broken or has a loose connection.  Try testing by turning on the parking lights and use a jumper wire and touch one end to the LED brown wire terminal and the other end to the LED brown wire terminal. If the light works then just use that wire and splice it to the wire and connect the other end to a mounting bolt.  Or determine where the actual wire run is broken and fix it.

[esty]

simple way...........jump a wire from the grounded side that works to the other that needs a ground

[NicholasMav]

Thanks for your responses!  I'll try those out, and to answer one of the questions above, yes, the Driver's side worked prior to the LED conversion.  I've also thought the LED array's may be bad.  I'm going to talk to the company tomorrow about that.

 

thanks again!  I'll respond when I get it up and running.

 

NM

[eurotrash]

you so kray..

[kavadarci]

I did led conversion just recently.

With leds is that you need resistors to work (blink) properly.

If your regular bulb works then I bet it is the resistor.

Also, pay attention to the connection, some leds are shorter and they don't make full contact.

[NicholasMav]

Just a quick update: I (sadly) found out that I had just plugged the LED's small plug into the car's housing upside down.  Not sure why it fits both ways, but it happened...not proud.  This all after I replaced several fuses and lots of head scratching.  It all works now and is very bright.  

Thanks again for all your input!  

 

Yours in complete "newb-ness",

NM

[ifayeoh]

Good catch, thanks for the update

frank

[eurotrash]

Hey Nick, maybe mark this 'solved', for those researching later..

[MoBrighta]

Hey,

I came to the party late, but good work solving it.  Sheesh - upside down eh? 

 

I bet you ask the vendor "Why is this possible?????"