Spotted - but what is it?

[adam quantrill]

Apart from very oily! Maybe a couple of power resistors?

Found underneath the supercharger (on normal cars on the LHS inside front wing near the power steering).

Any ideas? Reson I ask is that one of them appears to be partly broken - perhaps by someone trying to open the power steering reservoir.

Also - does anyone have a 400SE wiring diagram - I think things are a bit different to the normal V8 one out of the Bible, judging by what the fuses do.

Edited by adam quantrill on Sunday 28th January 17:21

[jmorgan]

Like this one? I can certainly try to trace the wiring if no one else knows off hand. Pair of wires disappear off somewhere and its bolted on the throttle linkage thingy.

[pwd95]

Always wondered what they were for

[DJC1001]

They are resistors feeding the dim part of dim/dip headlights.

David

[dickymint]

Put a match to it, walk away whistling, and claim off your insurance

[wedg1e]

DJC1001 said:

They are resistors feeding the dim part of dim/dip headlights.

David

Aye, I'd have said that.

[rev-erend]

Funny - I was thinking balast resistor for the coil .. never heard of resistors for headlights.

[honourablepickle]

my old v8 s had these - never did get round to working out what they were for.......
hp

[adam quantrill]

Well if they are ballast resistors then I'm slightly worried - one having a broken end which could snap off at any moment. Then - no sparks! Headlights makes more sense - you would only bother with one R for a coil. I wonder if it's for when you are on sides only - the pods come up on mine for sides, which seems a bit silly really.

I'll attach a meter lead to one and see when it goes live - headlights, ignition on etc...

[racingsnake]

They're ballast resistors for the ignition mate had one break on mine and took it the local auto elects supplier dead cheap to replace.

[honourablepickle]

i wonder why my v8 had no ignition problems then as mine were falling to bits .......
hp

[jmorgan]

Had a shufty and it disappears into a loom behind the dash. No idea where the wires go after that without further investigation.

[taz turbo]

I have one, it's for the slow(er) speed for the interior fan.

My previous wedge had two, the second one was for the dim(er) setting for the instrument back lighting.

Regards,

Chris.

[rev-erend]

racingsnake said:

They're ballast resistors for the ignition mate had one break on mine and took it the local auto elects supplier dead cheap to replace.

That makes sence .. I will trace mine soon as the big thing in the middle in out of the way at the moment making access to things like this and the crossmember very easy.

Did I mention the engine is out

[racingsnake]

HP said "i wonder why my v8 had no ignition problems then as mine were falling to bits ......."

All they do is stabilise current to the ciol when the starter motor takes power so there's no voltage drop at the coil while starting, once your running theyre not needed really. They are just a compressed version of a long wire so unless totally crumbled it will still run ok even if they are pretty shagged.
Not likely to cause a misfire or anything like that.

Edited by racingsnake on Wednesday 31st January 16:42

[adam quantrill]

I thought a ballast resistor did the opposite. Under cranking it's shorted out and the coil is exposed to full battery voltage (which will be 9 or 10V). Under normal running it is in series with the coil primary and reduces the 13 or 14V battery potential down so the coil doesn't overheat.

[racingsnake]

That's what I was feebly trying to say, basicaly stabilises the current at the coil, got my wires crossed though - pardon the pun.

Edited by racingsnake on Wednesday 31st January 20:17

[hamish400]

They are ballast resistors as fitted in pre-electronic ignition days.

On my car they are wired in to the the dashboard light dimmer switch circuit to drop the voltage. (Circuit is not shown on the wiring diagram).
Switch position 1 full illumination
Switch position 2 dims dashboard lights - ballast resistors added (in series) to dashboard light power supply
Switch position 3 switched dashboard lights off.

Lucas still sell them.

Rgds
Hamish

[hamish400]

Adam,

Drop me an e-mail if you still need a wiring diagram, or a copy of the relay layout drawing. I will scan and send to you.

Rgds
Hamish

[jchase]

AFAIK ballast resistors were only used on points ignitons. Electronic ignition modulates the coil dwell time, so as to achieve 8 amps through the coil just before field collapse. So a series resistor would do little to change the energy in the coil. Of course who knows what TVR did at the factory!