Full Beam Latch relay help

[Dax SC]

Any electrical gurus out there?

I've ditched all the Sierra column switchgear, but need advice on wiring up the full beam switch. I've sourced a new indicator column switch from Tri-State Motorsports, and believe it is of the same type used on the original Cobras (from a VW Karmen Ghia). There is a button on the end of the indicator stalk, and it is the press/release type, i.e you have to hold it on.

I have wired up a 5 point relay through the main beam, so the when the main beam lights are off, I can use the indicator switch as a full beam 'flash'. When the main beam light are on, this flash facility is disconnected, the idea here being that when the switch is operated the full beam stays on. Touch the switch again, and full beam is off. I know I need some kind of latching relay for this to work (a pulse of power closes the relay contacts, a pulse again opens them and so forth). I have sourced two different types of latching relays from RS Components, but both apear to required two separate power inputs to make the relays open or close. I only have one power source from the indicator switch. Anyone got any ideas?

Wilf, if you are reading this, I believe your Crendon used the same sort of set up-the switch is the same.

Thanks

[kdavies3]

Hi Mark,
a very interesting thread indeed, I'd like to know more about the stalk you've bought.
I'm desperate to lose the crappy Sierra ones myself.
My guess is that Simon P is the wiring guru, Where are you Simon?

[kdavies3]

Hi Again Mark, is this the one?

http://www.tristatemotorsports.com/D...ct.cfm?ID=4112

[Dax SC]

Hi Kev


Yeah thats the one. I'll post some pics of the conversion around the steering column when I get a chance.

[SimonP]

At work, that's where I was!!

What you need is one of these babies from a Jag - but as the page shows that they have a tendency to melt, wire the contacts of this latching relay so that they only switch your existing high/low beam relay(s).

http://jag-lovers.org/lumps/tech/basics/relays2b.htm

Note though, the author has got the relay type as DPDT, which it's not - it's SPDT!

Simply connect the coil of this latching relay through your momentary-type push button on the stalk!

Simon.

[wilf]

Mark - you are in luck, I kept the details of my set up.

Essentially I have two relays, the idea being that when I have no lights or side lights only, the momentary "make" switch on the VW stalk works as a main beam flash facility.
The first relay is just a simple SPDT thingy - just senses if you have none/sidelights or headlamps selected from the main lighting switch, and sends power either to the main beam relay (flash) or to the coil of the special relay (dip/main).

Once headlamps are on, the same stalk switch works as alternate main/dip/main/dip etc by pulsing a special relay (part number 210-6622 from RS, octal base is 403-235). The relay dsecription is " G4Q-2125 DPDT 12V coil relay".

That is not really a latching relay - it works by having two sets of contacts, alternately made/opened as the relay is pulsed.

The only thing that makes the whole thing work is the fact that the Crendon loom has separate relays for dip and main - all my system does is energise the relevant coils on those relays.

You also need a diode in the circuit to stop power from the "flash main beam" output getting back into the special relay.

I do have a drawing of the circuit, it is very "homemade" and refers to Crendon loom colours, but if you email me your fax number I can send it to you, FWIW.

The truth is that this is dinosuar stuff - I am sure that an elctronics guy could make something very much neater. But I like the clanging of that old octal base relay!

[tonym]

Wilf, I'm surprised you can hear the relay with your 427 ford rumbling away

[madjohnny]

Mark, my Peugeot 205 has the same latching system on it, I could scan the wiring diagram in for you if that will help then you may be able to utilise the peugeot latching relay.

[Dax SC]

Thanks for the helps guys.

I know the type of relay that I need, I just didn't know if it existed!

Wilf-I don't think RS stock that part any more, either that or the code is now diferent.

Simon- that Jaguar link is superb-That is the relay I need!! A mechanical latching relay instead of a magnetic one.

John-Looks like I now have the option of Peogeot 205 or Jag. A visit to my local scappy tommorrow I think!