Newbie - S1 Electrics

[Philk]

Hi All

Have recently taken possession of an S1 OTS and am slowly working may way through the car working out the various tasks that will need to be done to get it through its MOT. Some will have to be done by a garage and some I will want to undertake myself. Having tested the electrics:

- The car will start and run (ie petrol pump, starter motor etc all okay).
- Brakelights, headlights and sidelights are fine as is the reversing lamp
- Windscreen wipers work
- Interior rear light works from dashboard switch

However, the horn does not work, the heater fan does not switch on, the indicators do not work and the night time instrument lights do not come on. I don't believe the windscreen washer motor is working either.

Looking at the operating guide, these seem to span more than one fuse and some of things that are working should not be working if it is a fuse. Do the above symptoms ring any bells with anyone for a common easy to find cause before I start the laborious investigations circuit by circuit?

Many thanks!

[chrisfell]

A very useful resource on this site is the knowledge base. Look at the board index.
Someone has very cleverly colourised and cleaned up the wiring diagrams.
Using this you should be able to trace the problems.

As for the horns, this depends where they are fitted. If they are on the radiator frame, the wiring is attached to the engine frames. If they are in the bonnet, the wiring is through the multi pin plug on the LHS front wheel arch. Somewhere, probably on the LHS engine frame will be the horn relay.

Fortunately, all E-Type wiring is agricultural. You can see the wires and trace them back to source.

[Philk]

A very useful resource on this site is the knowledge base. Look at the board index.
Someone has very cleverly colourised and cleaned up the wiring diagrams.
Using this you should be able to trace the problems.

As for the horns, this depends where they are fitted. If they are on the radiator frame, the wiring is attached to the engine frames. If they are in the bonnet, the wiring is through the multi pin plug on the LHS front wheel arch. Somewhere, probably on the LHS engine frame will be the horn relay.

Fortunately, all E-Type wiring is agricultural. You can see the wires and trace them back to source.

Hi Chris

Many thanks for this. That sounds exactly what I want. I can't find it though on the site. Do you (or someone else) have a link for the page on the forum?

Regards

Phil

[cactusman]

Horn may be the horn button or wiper contact in the column or the relay which is on the lhs near the battery. Indicators...check the bulbs....the flasher may have died or the contacts in the stalk are dirty. The instrument lights are powered from the same circuit as the side lights. The dim setting puts a resistance in the circuit so if dim does not work but bright does then the resistor mounted behind the switch may be at fault. Also you should check all the various fuses and make sure the fuse holder contacts are all clean..

[Heuer]

Phil

Have a look here: viewtopic.php?f=16&t=700

[rfs1957]

Phil,

I found keeping track of my wiring required my own wiring diagrams, and this post

viewtopic.php?t=5214&highlight=

shows up some of the surprises I came across - some of which were standard and original, and which I thought were dangerous - and some of the modifications I made, all without really running any extra wires outside the standard harness.

[Philk]

Many thanks guys. I found the wiring diagram, printed it off and am slowly working my way through the car circuit by circuit. Issues found (and corrected) thus far:

- Fuse 7 was not slotted into its correct position but was actually bridging the gap between the connectors for fuse 6 and 7!!. On correcting this anomaly a number of things unsurprisingly began to work properly.
- Wiring reversed on Lucas 2SJ washer motor. Corrected and now working. Next challenge is that the hose from the washer bottle into the bulkhead is missing! Any hints for how to deal with this would be most appreciated.
- Map Light cables not connected. Simple fix. Map Light now working on door openings but not from the Map Light switch itself. Contacts seem fine so possible a faulty switch.
- Cable not connected to the horn relay. Corrected and horns now working.
- A bit of a Heath Robinson wiring arrangement found around the Heater Motor. Now working on High speed but not low. A bit of wiring seems to be missing so I need to find a picture of a properly wired Heater Motor to see what it should look like. If someone has a S1 3.8 with things correctly wired, a picture would be great.
- The heater fan motor is making a bit of a horrible screeching noise at high speed so that also needs investigation.

Further investigation still required around the instrument panel lamps (none working). Is this likely to be a particular component given none are working at all?

[cactusman]

Low speed likely to be a failed heater motor resistor. The slow speed was crudely implemented by using a resistor in series with the motor. It is fitted on the outside of the motor housing. Can't recall its resistance but it should be just a few ohms. Screeching is probably a dry bearing. Strip, clean and lubricate the motor. Not near my car at present but i think I have seen a picture on here before. The instrument lamps are fed from the side lights feed via the two position toggle. Wires are mostly red.

[Jerryslinn]

My wiring loom has 3 purple/yellow (PY) wires leaving the loom adjacent to the lower picture frame member.
Two exit together on near side (left) and are not as heavy as the single cable which exits on offside (right).
All three extend about 6 inches from the loom and are obviously positioned to connect to a pair of horns fixed to the lower picture frame. All three have spade connectors. My question is why are there three wires when it would seem that two would be sufficient and why are they different gauge wires? I have traced back to the horn relay which is where the PY wire originates.

[christopher storey]

It sounds slightly strange. My diagram shows a single PY feed from the C1 terminal of the relay ( which logically would be the heavier wire because it carries the current for both horns ) and then a double bullet connector from which emerges two PY wires, one to each horn. These logically will be the lighter gauge wires