Electrical issues

[bozman]

Trying to work out the issues with my S2.  Currently looking at the electrical gremlins. I have found several cut wires, loose ends and general chaos throughout so far.

My first oddity starts with the window switches. Press either of them up or down and the radiator fan comes on, no window movement. Same is true with the headlights, but they come on along with the radiator fan. Any quick ideas where I should start looking?

Also, the horn beeps if you put some side-to-side torque on the steering wheel (there is no horn button hooked up on the steering wheel).

All the gauges work, which is good news. Blinkers work.

[EuropaTC]

Sadly, there's unlikely to be a quick fix for this one, if I were in your position I'd go over the individual circuits so I could be happy there wasn't an electrical fire hiding away. Joe has put a link to the wiring diagrams so if you don't have one yet, that's the starter;

http://www.lotuseuropa.org/LotusForum/index.php?topic=752.0

I usually print & laminate a copy, easy to wipe clean and more robust when you're working on the car.

The horn might be a simple fix. It works by having a live feed (green wire) from the fuse box to the horn with the earth return circuit (purple/black wire on my car) going up to the horn push via a brass slip ring that's situated at the top of the column, just below the steering wheel itself. When you press the horn push it goes to earth via the steering shaft/column and sounds the horn.

If yours is going off without a horn push simply be heaving on the wheel itself, then you're earthing the circuit. Look for damage or trapping on the steering column wire (purple/black) and then the brass slip ring; that should be insulated from the outer steel of the column by a plastic carrier and be well away from the inner steering shaft, which is also an earthed item.

The other problems sound like someone's just messed up connections and could be anywhere, hence the need to check individual circuits.  I think the window switches and rad fan are both on the green wire fuse with the windows permanently live from the fuse feed side (effectively un-fused) but I've modified my car so check on your diagram.

Final suggestion is that unless the wiring is recent then clean and re-make any earth connections as you find them, especially the light units or anything exposed to weather. Poor earths are regular bugs with old fibreglass cars.

Brian

[jbcollier]

The column surround has an irregular opening that can touch the horn brush ring.  A slight realignment of the surround should do the trick.

On the other electrical issues, start by checking and thoroughly cleaning all your ground points -- electrickery will make its way to ground through the most bizarre and circuitous routes if the normal ground path is toast.

Once you are sure of your grounds, go through each problematic circuit one at a time.  On most circuits you start at the fuse block (old fuse blocks commonly have corroded or loose connections) so give the block a thorough clean and inspection next.

English wiring is commonly derided but, invariably, it's the hamfisted, amateur repair attempts that are the source of most grief.  For example, on cars with emergency flashers, the emergency flasher switch also controls the power supply to the signal flasher relay.  As the years roll on, the little used emergency  flasher switch develops corrosion and the power to the signal flasher relay disappears.  Your "expert" gets in there and starts chopping and splicing wires to "fix" the problem when a simple cleaning of the switch's contacts would do the job.

[bozman]

Thanks for the great responses.

Turns out it was indeed a bad ground . . . the one that is just below and to the right of the ash tray on the back of the dash panel.  Also, oddly, the two brown wires for the power windows were hooked up to the ignition switch, as opposed to the fuse panel.  I reset those, got the power windows working again, and other electrical issues seem to be improving as well.  The fuse panel had some corrosion as well, so that now functions better.

I'll dive into the horn issue later this week.

Thanks again!