now, this really got interesting...electrical problem

Hi guys,

I have a '79 B roadster. A few days ago, I wrote in that my right (passenger) headlight went out and got alot of good info. So, popped off the ring, replaced the headlight (had an extra), but it didn't work either. Odd.

Had to run off, so put the original one back in and hit the road. Started to get dark on the way home, so I, of course, turned on the headlight(s). I then noticed that I in fact had TWO working headlights. "Good", I thought.

It was about that time that a guy pulled alongside and informed me that I had no taillights. Brake lights, but no taillights. <sigh>

Checked the fuse and, sure enough, the second one from the top was blown (25 Amp). However, replacing it with another fuse didn't solve anything (I couldn't tell if that fuse subsequently blew immediately as I didn't have an Ohm meter with me).

What I currently have working is 2 headlights and ONE parking light (front driver-side). No other lights (dash lights work).

I thought that I was told that the lights for each side were controlled by separate fuses so that if one fuse blows, you would still have partial lights.

Any thoughts as to where to begin to try to track this thing down???

Thanks in advance!

Hi Paul,

All of the right hand park/running lights are on the 2nd fuse from the top and all of the left hand park/running lights are on the top fuse. I suspect you'll find the second fuse blown again which means you have to go looking for a short. Check the actual connections on the fuse block to make sure corrosion isn't causing you some grief because with the varied symptoms you've described, that's sort of what it sounds like.

The low beam portion of the headlights are not fused. Power comes from the connection on the starter up to the headlight switch and then out to the lights themselves (kind of scary....perhaps having the headlight switch melt is supposed to act as the fuse). The high beams are fused and they run from the lower fuse on the block. I hope this helps a bit.

First off, go to the site here that has all of the wiring diagrams.

THEN, track it down. I suspect that you have a wire that is grounding out. It can be inside the trunk, it can be around the fuse box, or it can be around the headlight switch.

Since, you are talking BOTH headlight problems, AND taillights, I would focus around the switch and the fusebox area.

Someone else will chime in on some more info on your year specifically.

GL,

Brian

I had all kinds of lighting problems until I took a hand held media blaster{used glass beads},removed all the fuses and unplugged all the terminals and procedded to blast every thing clean.I then applied some trucklite compound to the fuse retainers and the terminals and have not had a problem since then with the lighting.

Paul,

advanceautowire.com is the site with schematics for our LBC's - click on "stock schematics" This is a very good site as they offer tech advice, relay kits, and various and sundry other electrical bits Page 25 should be representative of your car.

Start by cleaning and checking all connections, bulbs & sockets, the switch itself, etc. in the lights circuits. Could be you simply had a fuse fail and the only problem is faulty bullet connectors which are readily available from mossmotors.com The female connectors are notorious for failing and causing intermittent problems. They come in single, double, and triple (161-730) connection, I needed a handful of all three to sort out my electrical gremlins.

Good Luck - Hope this Helps

When you find the correct wiring diagram at advanceautowire.com , copy it to a cd. Then take the cd to the British version of Kinkos and have it blown up and laminated. Then post it on the garage wall for future reference

Most problems with the lights are due to bad connections with the (always black) ground wires. Check the black wires inside the boot that are fitted to the bolts of the license plate holder. At the front, there are also black wires connected to the harness on both sides just below the horns. It i not unusual that the bulled connectors of these wires tend to corrode and the lights fail.

My guess is that something in the boot is moving around shorting out a wire. And since you have intermittent issues with the non-fused headlights, your grounds are problematic, and you have a lot of corroded wire connections that need to be cleaned up. You have your work cut out for you!