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Headlights - suddenly stopped working

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RobWarren

Jedi Hopeful
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I think I must be breaking records for new topics right now.

Phase II BJ8

I went for a drive last night and then stopped to go out for dinner. When it came time to go home it was dark so I flicked the Lights switch on all the way but no lights came on.

I turned it off and then on again to halfway and apparently the pilot lights came on and then went off. Still no headlights. No panel lights either when I flicked that switch. Thankfully home was just around the corner so I got home ok. Everything else working just fine.

After a long, rattling drive on dirt tracks recently I'm fairly sure that something must have come loose but I'm no electrician so I thought I'd ask for the most sensible places to check.

As the pilot came on the second time I'm assuming this isn't a fuse issue but I'm failing to make much sense of the wiring diagram I found. Are the fuses inline for headlights or in the fuse box?

Is it worth removing the panel and checking the switch itself (and is this difficult to do)?

Your experience and advice would as always, be much appreciated.

Rob
 
As originally supplied, the lighting circuit is not fused, so unless one's been added, you can rule out a blown fuse. In my opinion, an inline fuse under the dash (or wherever) is recommended.

It's most probable you have a loose connection, perhaps right on the switch.

The switch is next in the chain of troubleshooting links; you can use a clip-lead to connect the brown wire to either the red ("pilot" circuit) or blue (main beams) wires.

If you were an <span style="font-style: italic">electrician</span>, you wouldn't guess, but grab your volt/ohm meter and determine how far the 12VDC goes, before there's a break in the circuit :wink:
 
Hi Rob,
No, no fuses for the headlights. If everything else in the car is working, I'd concentrate on the headlight switch itself. Probably best to disconnect the battery first. Here is a photo of how the switch should be wired. If nothing is loose, pull the brown and blue wires off and use an ohm meter with the switch to the headlight position. Brown and red would be the running lights. I posted a color wiring diagram in the Wiki a while back for later BJ8s. That may help you read the diagram.

I'm a slow typer. Randy covered most of it. :bow:
 
Great stuff...thanks to both of you.

I'm building up a sizeable list of jobs now, to the point that people have asked what I'm doing over the weekend and I'm now simply replying "Tinkering with Ruby" and they roll their eyes as if I'm far too young to be using words like "tinkering" instead of "chasing tail".
 
Well you certainly don't want to be chasing Ruby's tail. That means either someone stole her or the parking brake failed.
 
Righto,

I pulled the switch out of the back and had a look at it. Interesting.

The blue and brown wires were both melted at their respective terminals on the switch and the double-red wire seemed to be ok but part of the plastic casing had melted I think due to the blue one.

The right wires seemed to be attached so I removed all of the plastic casings that were damaged and taped them with electrical tape to ensure no shorting but still no avail.

I have a feeling that the switch itself might be damaged. Some photos attached. Apologies for poor quality! I'm unable to view these due to work proxy settings for external image hosting websites so if they don't work, please let me know!

Rob

[img:left]<img src=\\"https://xs135.xs.to/xs135/09020/light_switch_1649.jpg.xs.jpg\\" alt=\\"\\" />[/img]

[img:left]<img src=\\"https://xs435.xs.to/xs435/09020/light_switch_2270.jpg.xs.jpg\\" alt=\\"\\" />[/img]

[img:left]<img src=\\"https://xs135.xs.to/xs135/09020/light_switch_3428.jpg.xs.jpg\\" alt=\\"\\" />[/img]
 
Hi Rob,
I would check the entire headlight circuit. My feeling is that there is a wire grounding out somewhere between the switch and the headlights. The switch seems to have acted as a fuse here. Check where the blue wires go through the firewall and up near the headlights themselves first, then work to the middle if you don't find anything there. My guess is you want to order a new switch. The heat generated may have caused internal damage. In your third photo (for the ignition switch wires), the white wires are your switched hot for the car. They go to the fuse block and tach and later on to the ignition system. The red wire I believe is an add-on. Maybe for a radio as you said. Stock red wire is for the running lights.
 
"Switched hot for the car?" - I'm not sure what you mean - I assume hot means that it's a power line. Does the white not being connected to anything cause problems?

Rob
 
Hi Rob,
Yes, it's a power line. Basically, there are two types of circuits in the car. Always hot ( a brown wire), and switched (a white wire). A brown wire feeds the ignition switch, horn and lights. When the ignition switch is turned on, it feeds the fuse block via the white wire, which in turn powers things like fuel pump, fuel gauge, wipers.

That white wire will need to go back on the ignition switch to be able to start the car.
 
A common place for the "short" is the license plate light (goes on when the head lights are on). Fuse it and other head and tail light wires with line fuses. Cheap and easy.
 
Greg,

The white wire as pictured in the third photo I sent it, was providing no service, as the car starts just fine. I know it looks odd hanging down like it is, but the car starts up first time, everytime.

It's only the lights that aren't working. Actually I've not checked the panel lights, thinking about it.

I'm worried now!
 
Ah, so you're saying that white wire in the third photo is attached to the ignition switch at the other end? As opposed to the wire pulled off the ignition switch just before you took the photo. If it's the first then I wouldn't worry about it, maybe an accessory a previous owner took with him. Maybe just remove the wire entirely if it's just hanging there.
 
Hi Rob,
Everything that has been said by the others is correct.
Your old switch melted because of a short circuit.
From your pictures I noticed that you still have your center console installed. You must be a contortionist !
The center console is easy to remove and will give you better access to the switch and wires in the dash.
The short could also have been just the switch going bad after
40 + years. You said you don't know much about electricity so
here is some trouble shooting for beginners. Turn off the big disconnect rotary switch next to your battery in the trunk ( boot ) before you start doing anything.
1.. Order a new light switch.
2.. Remove your center console so you can get to the wires
easier.
3.. Make certain that the metal part of the wires are still firmly attached to the connectors that have the melted plastic insulation. If any have detached from the connectors, you will have to obtain some new slide on connectors from a hardware or home improvement supply store and install new connectors on to the melted ends of the wires ( after trimming off all of the damaged wire ).
4.. If the metal part of the wire is still firmly attached to the slide on connectors but the insolation has melted away exposing the metal part of the wire, you will just need to insulate the wires were the insulation is missing. This can be done by cutting off the damaged portion of insulation ( be careful not to cut the metal strands of the wire ), and then use either heat shrink tubing or rubberized cloth type of friction tape. I would buy some pieces of heat shrink tubing big enough to slip over the ends of the slide on connectors and some of the tape. Don't use the plastic electrical tape that is commonly sold now. It will dry out and drop off after a few months.
5.. Now that you have your connectors fixed and insulated again, hook up the repaired wires to your new switch. Let the switch dangle loose under your dash and heater. Just make certain that none of the wires will touch any metal and short.
6.. Turn on the big switch in the trunk.
7.. Turn on your light switch one click to the parking light position. Quickly look to see if all four of your parking lights are on as well as the license plate light. If not, turn off the light switch and rotary switch. You will have to find the short in your RED wire circuit that feeds your four parking lights and license plate light. If just one or two parking lights are off but one or more is on, turn off your light switch and then you will have to trace the red wire to find the place it is touching the metal of the car ( ground ).
If just the license plate lights don't come on, look at the wire were it comes out of the hole in the trunk. That is a common place for the wire to short through the insulation and cause a problem like yours.
8.. Once you verify that all four parking lights are working, turn your panel switch on and then turn on the light switch again just one click. Check to see that all of your dash lights come on. If not, look for the problem with the red/white and black wires that connect to all of your gauges.
9.. Once you verify that all of your parking lights are working as well as your license plate light and your dash lights, leave them on and touch the sides and connectors on the light switch. Is anything HOT to the touch ? If so, you still have a problem somewhere in the red light wiring so you should seek another person that is knowledgeable with electricity or Healeys or both to help you find the problem.
10.. If you reach this point and everything appears normal and the switch didn't get hot, turn the switch all the way on to the headlight position. Quickly see if both headlights come on. If they both come on, touch the switch again and see if it is getting hot to the touch. If yes, turn off the lights and seek help finding the problem in your headlight circuit. If the headlights don't come on at all feel the switch and see if it is rapidly getting warm, if so, turn off the lights.
11.. If the switch is NOT hot to the touch but the headlights are not on when the switch is turned on, push the dimmer switch once. Did the headlights come on or does the light switch start getting hot to the touch ? If yes, the dimmer switch could also be bad as well as the wiring to the headlights.
12.. If the headlights work in both high and low beam mode. Let all the lights stay on for 5 minutes or so and then feel the switch again. Is it HOT now ? If not, then perhaps the only thing that happened was the original switch went bad and shorted after 40 + years of service.
..... You should get someone to help you that knows something about electricity if you get stuck trying to find out why one or more of your lights is not lighting up or if your switch gets real hot, real fast when you turn on the light switch.
.... If the light switch gets hot to the touch quickly after you turn on the light switch, then turn everything off and get some help.
:crazy:
 
tahoe healey said:
A common place for the "short" is the license plate light (goes on when the head lights are on). Fuse it and other head and tail light wires with line fuses. Cheap and easy.
Click to expand...
I agree about fusing the license plate wire, but I don't think it's the problem in this case. The red wire on the headlight switch wasn't damaged nearly as much as the blue and brown wires.
 
Thanks Ed - this breakdown helps a gread deal in helping me approach it in a systematic manner. I'm looking forward to tackling this this at the weekend now.

Much obliged.
 
Hi Ed,
Would it be prudent to install a 12 amp fuse inline with the switch for testing? That might keep the new switch from burning out if there is a constant short, an intermittent short from a rubbing wire is a different story. Might not show up until Rob is out driving. I'd be inclined to do a visual inspection of the wires beforehand.
 
I held off suggesting any changes until Rob is able to determine if he still has a short or not. It is prudent not to introduce anything new until after the situation as it exists is fixed.
If we start recommending that fuses be added before he knows the car is OK, he will not know if the problem is the result of one of the wiring changes that he made or it resides elsewhere in the existing wiring.
... After the problem is fixed and run for a while without any further electrical symptoms, then we should suggest at least a few inline fuses.:

One for all the lights, ( 20- 25 amps )
One for the red wires to the parking lights and license tag
( 5-10 amps ).
One for the fuel pump ( 10 amps )
One for the o/drive ( 15 amps ).
One for just the license plate lights ( 2-5 amps )
 
I was suggesting a temporary fuse right at the switch to keep the new one from melting if there is a wire grounding out somewhere. I've had hand tools weld instantly to car parts from the battery amperage.
 
It is certainly a good suggestion if Rob can make it happen.
Just substitute " is the fuse blown ? " for " is it getting
HOT to the touch ? " in the check list.
 
A few years ago I took a "color" wiring diagram and had it professionaly scanned(high resolution), and had it enlarged to 3' x 4'(and in color), and I use it to trace out my wiring. You can have the finished print mounted to a 1/2" or 3/4" substrate such as Ultramount or Gatorboard which both are light weight materials.

Have it coated with a product that allows you to use a grease pencil, etc.that can be wiped off with a cloth and you can trace out each individual circuit as you troubleshoot.

Mine hangs on the wall in my home office.
Patrick
 
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