Problem with tail/side lights

[Schrodinger]

Hi all

I'm after a bit of help with an electrical problem on my S4 - the the tail lights, side lights and panel lights have all stopped working and I can't find an immediately obvious cause. Does anyone have any ideas on the best place to start looking before I spend the bank holiday immersed in wiring diagrams...

Cheers
Jennifer

[bcmc33]

Jennifer,

The first thing to do on these cars when the lights go out - or any other apparent electrical failure (outage), is to check earth (ground) continuity. Probably the most common electrical failure mode.
In this specific instance I would connect a length of cable to the battery earth and touch the opposite end to the earth points on the lights just to see if they do come on.
To do the job properly, of course, you need to use a Multimeter (Voltmeter, Ammeter, Ohmmeter) to check the circuits.

I have the habit of adding more earth connections to the loom - (in series and/or parallel) whenever I'm working on the electrics.

With plastic body cars you can never have too many earthing circuits.

[Frank Howard]

Jennifer,

I'd start at the common denominator, the rocker switch.

[twincamman]

I would make or buy a trouble light ---then with the clamp grounded use the probe end to find where the power is or is not ----checking the fuse box --and ground points of the offending lights ---ed

[GrUmPyBoDgEr]

If everything else checks out & you still have a rear light problem the cause can be corrosion between the lamp holders & the rear light backplate.
Corrosion between the "spun in" lamp holders & the die cast back plate can also cause a bad earth.
However all is not lost, it is possible to solder some wire to all of the lamp holders & to the common earth.

Hope you get your problem solved & let us know the cause.
Cheers
John

[alan71]

I agree with Frank, look at the switch first.
The front and rear lights have separate earths so I don?t think that?s the problem.
It could also be the feed to the switch, then the head lamps won?t work either.

Alan

[Schrodinger]

Interesting, thanks for all the replies
I don't think it's the light units themselves as the brake lights both work fine in the same bulb and there's not much corrosion (everything is relative ). I'm doubtful about the rocker switch as the tail/side lights and the panel lights all stopped working at the same time and the headlights are OK, but I'll check them out. Then I'll go earth/feed hunting...
Thanks all, I shall report back!
J

[elan_fan]

have a look here

http://www.lotuselan.net/publish/wiring ... n_s4.shtml

where abouts in shropshire are you?

regards
Mark

[Frank Howard]

I'm doubtful about the rocker switch as the tail/side lights and the panel lights all stopped working at the same time and the headlights are OK...

Oops, my mistake. When you reported that the tail, side, and panel lights all stopped working, I suggested the rocker switch (next to the headlight pull switch) because I have since rewired mine so that in addition to the tail and side lights, the rocker next to the headlight switch also controls the panel lights.

As I recall, rather than "power" the panel lights, the panel switch simply completes the circuit to ground. I think the tail/side switch works the same way. You may find that both of these switches have a black wire connecting them (either directly or indirectly) to one of the chassis bolts that hold the bottom of the dashboard on. My prediction is that connection is the culprit. Before ripping the dash out, as an experiment I would remove the console and attempt to tighten (and loosen) the two lower dash bolts while the tail/side and panel switches are on. At the same time, have an assistant tell you if the lights begin to flicker. Best of luck.

[neilsjuke]

Sounds like a supply to the light switch fault or switch ,You could run a wire from the battary to a side light red wire this should then supply all the lights and panel lights if the switch is on be ready to remove if its a short so just flash the wire at first.
Neil

[Schrodinger]

Thanks again all, it definitely seems to be sounding like a supply problem, I best get looking into it!

where abouts in shropshire are you?

Hi Mark, not far from you - Much Wenlock