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Left tail, marker, plate lights [fan Latest too]

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JoshP

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Left tail, marker, plate lights [fan up-date too]

Here's the latest on my B and me tongue sticking out smiley...

So far, I'm happy to report that the new fan is still working and doing pretty well keeping everything at the 'N' mark. Even stopped in traffic, it never moves more than a shade above the 'N'. I'm pretty happy about that.

Last night, I came back from my girlfriend's house in my B. She calls me when I get home and asks if I knew that every light on the left rear of my car is out. She did say the brake lights lit up, but nothing else. I found that everything 'west of the Mississippi' on the rear of the car is out. The tail, side marker, and plate light on the left of the car is out.

I know that with many classic cars, the right side lights have their own fuse and the left sides have their own. However, my headlights and turns do work on both ends. My brake lights also work. I studied it a little last night and found that the above lights run on a red circuit.

It seems that, starting from the right side plate light, a red comes out to supply that light, and a black goes back into the harness. On the other side, a black comes out and goes into the left side light, then a red comes out and feeds two more reds which feed the tail and side markers. How am I doing thus far?

With a test light, I determined that voltage isn't getting to the aforementioned black or single red on the left side. It's leaving me somewhere between the left and right plate lights. I believe that it's a ground issue, but I've cleaned the trunk grounding point and even tried a ground I know to be good (a piece of bare metal on the tail light housing). No joy there.

Also, I put a jumper wire to connect the red from the right plate light to the left side lights. Everything lights up and lights up brightly.

Any ideas?
 
Re: Left tail, marker, plate lights [fan up-date too]

Bad connector somewhere along the red wire circuit would be my guess.
 
Re: Left tail, marker, plate lights [fan up-date to

Black should be a ground circuit, check the "Lucar" bullet connectors in the run from right to left for voltage. When you find the "hot" ones, the next connector to the dead side will be your "culprit."
 
Re: Left tail, marker, plate lights [fan up-date to

I cleaned each of the bullet connectors and put the jumper lead to each end to make sure they were conducting. Everything worked that way. Does the red go to black on the right side, and the same black supply the left side red circuit, or am I way off here?

My thinking is that the black on the right side goes back into the harness and comes out to supply the left side. From the left plate light, a black goes in and a red comes back out. The red that comes out connects to a 2 way connector which goes back into the harness and out to the tail/side lights. It wouldn't make sense that two reds would come out of the harness to supply one lead. That's my thinking anyway.
 
Re: Left tail, marker, plate lights [fan up-date to

There is a double bullet connector in the red wire, upstream of the right light, that splits the main feed to the two sides. That's where I would start looking. It's obvious you have power back that far, or the right lamps wouldn't work.
Jeff
 
Re: Left tail, marker, plate lights [fan up-date to

Josh, I just emailed you a set of color coded wiring diagrams for the MGB... It should be easy for you to figure the correct wire routing with this. /ubbthreads/images/graemlins/thumbsup.gif
 
Re: Left tail, marker, plate lights [fan up-date to

Yup-yup... don't go mixin' up the black ones with the RED ones. You'll let th' smoke outta SOMETHING.
 
Re: Left tail, marker, plate lights [fan up-date to

[ QUOTE ]
Yup-yup... don't go mixin' up the black ones with the RED ones. You'll let th' smoke outta SOMETHING.

[/ QUOTE ]

And OEM Lucas smoke is hard to come by these days /ubbthreads/images/graemlins/jester.gif
 
Re: Left tail, marker, plate lights [fan up-date to

oh yeah... let's not forget that it's NOT a fusing problem, because the lights on our B's aren't fused from the factory...

Unless, of course your wiring harness has fused itself to the chassis of the car, but if that happened you'd have let the smoke out and you'd have bigger problems on your hands than just the lights on the left rear. /ubbthreads/images/graemlins/smirk.gif
 
Re: Left tail, marker, plate lights [fan up-date to

Hehehe...I haven't let any smoke out yet. I try to be doubly careful around the electricals, since I'm still getting my feet wet (proverbially, not literally /ubbthreads/images/graemlins/tongue.gif)

I may have to invent a device that puts new smoke back in. I'll make millions! Errr...thousands...hundreds? Ok, maybe I'll make enough to buy lunch. /ubbthreads/images/graemlins/tongue.gif

Thanks for the wiring diagrams, Kenny! Those are super nice!
 
Re: Left tail, marker, plate lights [fan up-date to

[ QUOTE ]
I may have to invent a device that puts new smoke back in. I'll make millions! Errr...thousands...hundreds? Ok, maybe I'll make enough to buy lunch. /ubbthreads/images/graemlins/tongue.gif

Thanks for the wiring diagrams, Kenny! Those are super nice!

[/ QUOTE ]

Actually, it might pay the eBay final value fee if your lucky - hehehehehe

And, your welcome on the diagrams... I just remembered I had them. I'd offer 'em for the knowledge base, but I don't know who made them or if they are copyrighted. Someone put in a lot of time and effort though, and they are really helpful.

[edit] Actually I looked again, and the PDF's were made by Dan Masters, but no copyright info. [edit]
 
Re: Left tail, marker, plate lights [fan up-date to

Check the spade connector at the fuse block. There are two completely seperate wire running from the fuse block to the right and left side running lights. There should be a fuse with multiple red wires coming off one side. Try wiggling them and see if your tails come back.
 
Re: Left tail, marker, plate lights [fan up-date to

The schematics I have seen for the B, and the one I have for the 77 midget do indeed show the lights being fused. I realize this is not a midget, but I can't believe that the wiring practices would be so different. I know you said the turns work, but do the front parking light and side light work on the left side? It appears there is a seperate fuse for the left side and right side. Even if the front lights work, there could still be an issue with the connection for the red wire to the back lights. I would check for power out of the fuse to each red wire, if you haven't already.

Jeff
 
Re: Left tail, marker, plate lights [fan up-date to

When I checked the problem out, everything except for the left tail (brake lights/turns did work), side marker and license plate lamps worked. I traced the circuit back and found no voltage going to any connector. I cleaned them as I went.

Thanks to the diagram from Kenny, I traced the circuit back to the fuse box. I had checked the fuses a few days before and they all *looked* good. The fuse that went to the lights in question was the original Lucas 17/35 fuse (even had the little Lucas label inside).

I tested the feed side (top) of the box, voltage. Tested the bottom, no voltage. Blown fuse, duh, right? Not so much. I tested the bottom part of the fuse itself, voltage. What the...? Test the fuse prongs themselves, no voltage.

So, I removed the old Lucas fuse, cleaned the contacts and replaced it. Nothing yet...substituted another fuse from the box that I know to be good. Voila! We have light! But why am I getting a reading on the fuse itself and not the clean prongs?

Answer: there was a spot of corrosion on the bottom of the fuse itself where it made contact with the prongs. I didn't catch it on first inspection; the corrosion itself wasn't horrible. But it was enough that it wouldn't pass voltage to the prongs, but would pass it to my test lamp when I touched the one clean spot.

I cleaned the original fuse up and replaced it where I'd removed the other one. Works! All the lights are back.

Thanks for all the help!
 
Re: Left tail, marker, plate lights [fan up-date to

I've a small piece of ScotchBrite rolled up and stowed in the fusebox where the "spares" are s'posed to be. Comes in handy. I keep fuses in the glovebox where they BELONG /ubbthreads/images/graemlins/wink.gif
 
Re: Left tail, marker, plate lights [fan up-date to

[ QUOTE ]
Actually I looked again, and the PDF's were made by Dan Masters, but no copyright info. [edit]

[/ QUOTE ]

They do have a copyright, but that's just to keep anyone from selling them. Feel free to distribute them to anyone who needs them (just don't sell them, please). They can be found at https://www.advanceautowire.com Just click on the "stock Schematics" button on the left.
 
Re: Left tail, marker, plate lights [fan up-date to

You did a very nice job on those diagrams. Very clear, color coded nicely and easy to decipher. The diagrams in the manuals, while they're complete, can cause massive headaches.

I'm going to have to get them printed up really big and put them up on my garage wall. You should submit them for inclusion in the knowledge base here.
 
Re: Left tail, marker, plate lights [fan up-date to

Ok, thanks Dan... Glad to here about free to anyone who needs 'em... I wouldn't consider selling 'em anyway - not having made them myself. That's why I said what I did earlier. /ubbthreads/images/graemlins/thumbsup.gif

Glad you got it fixed Josh. /ubbthreads/images/graemlins/grin.gif
 
Re: Left tail, marker, plate lights [fan up-date to

[ QUOTE ]
I know that with many classic cars, the right side lights have their own fuse and the left sides have their own. However, my headlights and turns do work on both ends. My brake lights also work. I studied it a little last night and found that the above lights run on a red circuit.

[/ QUOTE ]

That goes to my question in the "Standing Lights Question thread (https://www.britishcarforum.com/ubbthread...p;page=1#200711)...while I've never seen a wiring harness for them, I'm wondering if they were ever built that way for the UK/Europe markets?
 
Re: Left tail, marker, plate lights [fan up-date to

Wouldn't take much more than a "supplimental harness" and another switch! Hmmm.... "Confuse-A-Cat!"
 
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