74 2500M: adding a Smiths clock

[Renaldo]

Guys, I've bought a very nice used Smiths clock on E-Bay, and I'll be adding it to a gauge panel below the dashboard.

My question relates to wiring, which, generally speaking, scares me to death.

Any tips or advice on the best way to wire the clock in to avoid problems?

Is it by splicing in somewhere? If so, where and how?

Ron

[pridaux]

You need a permanent live or you will be setting it every time you use it.
You may find the lighter socket is permanent live.
In my case its not I could not find one so I fitted a direct live with in line fuse and works great.
Andrew

Edited by pridaux on Thursday 14th March 07:53

[GadgeS3C]

Ron, as Andrew says it's not too complicated, even if you have to run a live feed. But make sure that there is an appropriate fuse in the circuit however you do it, GRP and sparks mix too well!
Gary

[phillpot]

.....and if its illuminated you'll need to pick up a feed for the bulb from the instrument lights then there's just an earth to find !

[gmw9666]

why not wear a watch? :-)

[Renaldo]

Guys, forgive my ignorance, but is it possible to get a power feed directly from somewhere, rather than splicing in? If so, where do I connect?

And for the ground, I was thinking I could ground to one one of the in-dash instruments? Yes, no?

And by the way, wiring scares me so much, I might just wear a watch and be done with it.

(I'm reading a book on basic auto electrics right now, and I'm just starting to understand all this)

[Terminator]

Purple wires in M-series cars are normally live, Black wires are earth (ground).

This diagram should help you find the best ones to connect to.

If it looks too complicated, then it probably is (for you)

[RCK974X]

Renaldo, just a general note....

The wiring in your 'M' should be the standard colour coding used in British Cars up to about 1980. There is info on the web. Every wire has one or two colours which define what its purpose is. Wiring seems scary but it's not that bad, just go through it step by step and make sure you understand as you go.

Example Colours
fused live - purple. (use this for the clock)
earth - black
unfused live - Brown (these are the dangerous ones !)
switched live (i.e., Ignition on) White.
side lights - red
main beam - Blue with white trace
dip beam - Blue with red trace
green red - indicators one side
green white - indicators other side
and so on.....

Later European/ISO scheme has totally different colours, from about 1980 onwards.

If you want to be really scared, buy a wedge like mine, which is wired totally in BLACK !!
Now that really does take some time to fix electrical issues !!
(Yes, I know they originally had little coloured sleeves, but after 30 odd years, they mostly fallen off now...)

Edited by RCK974X on Thursday 14th March 20:18

[Renaldo]

Thanks Andy and others. Very helpful.

I'll give it a try. As for splicing, I bought some "scotchlock" type splice connectors.

Should they be up to the job?

Ron

[GadgeS3C]

RCK974X said:

If you want to be really scared, buy a wedge like mine, which is wired totally in BLACK !!
Now that really does take some time to fix electrical issues !!
(Yes, I know they originally had little coloured sleeves, but after 30 odd years, they mostly fallen off now...)

Edited by RCK974X on Thursday 14th March 20:18

Or buy a 3000M like ours - they used the M series to practice the all black wiring...

[GadgeS3C]

Renaldo said:

Thanks Andy and others. Very helpful.

I'll give it a try. As for splicing, I bought some "scotchlock" type splice connectors.

Should they be up to the job?

Ron

Scotchlocks will do the job but I wouldn't mention too loudly that you're using them, OK for a quick fix (such as splicing in a low current clock) but not the "proper" way.

If your car has bullet connectors you can get snap connectors in various sizes that let you piggyback connections - see below



Not sure of a source for them in Canada but any "old" car supplier should do them.

Someone will no doubt tell you to get rid of the bullet connectors but they are at least period for the car.

Good luck,
Gary

[phillpot]

Renaldo said:

I bought some "scotchlock" type splice connectors.

The "Devils Invention"

but, just about acceptable for something very low current, like a clock

RCK974X said:

If you want to be really scared, buy a wedge like mine, which is wired totally in BLACK !!

TVr "practised" that on the Taimar first

[Renaldo]

Thanks boys. Your advice is invaluable as usual.

Where would be a preferred grounding point?

I was thinking I could ground out at one of the dashboard instruments (one of the screw "pegs", with the knurled round nut for tightening down the gauge), since my M has a bunch of black ground wires aleady attached to each.

Yes, no?

Ron

[pridaux]

Yes

[RCK974X]

OH, right.. I didn't know that TVR practised the "all black" system on the later 'M' and Taimars too, I thought it was only the early wedges. Anyway my sympathies to all fellow sufferers....

Renaldo, Yes to the gauge ground, and you can take illumination/side lights from a guage to the clock light also, if it has one.

Scotchlocks are regarded as an invention of the Devil, because they tend to cut the wire itself, as well as the insulation, so you can get hot spots and broken wires. As said above, OK for low current like a clock, but I still hate them !

Edited by RCK974X on Friday 15th March 19:32

[Renaldo]

Thanks one and all.

I had no idea the "Scotchers" were held in such contempt. Good to know.

Despite that, it sounds like most feel they are passable (barely?) for wiring the clock.

Think I'll try them, keeping their limitations in mind for future use.

Ron

[ausi steve]

Renaldo, it was suggested by Colin that you look at a wiring diagram that is available on line, whilst it of some help be aware that there are some faults i.e. as in the rear tail light wiring, as depicted it would cause a short circuit.Take care when using it.

[Renaldo]

Steve, thanks for the warning. I'll be suitably careful.

Ron