[edit: beaten to it, damn my feeble drawing skills
[Edited on 29-12-09 by flibble]
edit:picture flipped for easier comparison, couple of subtle differences ^^
[Edited on 29-12-09 by flibble]
This is the very last piece of wiring left on the car.
As you all probably know by now, my master cylinder provides a 12v supply when the fluid level is ok rather than the normal providing a 12v supply
when the level is low.
I have wired a 5 pin relay to switch the light on when the current is removed (level is low).
This is all fine except when the float moves back up again (current is re-applied), the light stays on so the relay isnt switching back and i cant
work out why.
It sounds like you have it wired wrongly. You should have:
Ignition supplied 12V to terminal 30
Master cyl 12V to terminal 85
Earth to terminal 86
Warning light to terminal 87a
If you have different numbers, e.g. 56 and S on the terminals, you have a latching relay, which is no good to you.
Cheers R
This is how i have wired it:
Think it'd be like this could be wrong quite easily though
[edit: beaten to it, damn my feeble drawing skills
[Edited on 29-12-09 by flibble]
edit:picture flipped for easier comparison, couple of subtle differences ^^
[Edited on 29-12-09 by flibble]
So if it is wired right, why wont the light go off when the float is put back in the reservoir?
Speedy, you haven't wired it right! Your diagram is nothing like my description or flibble's diagram.
why use a relay when the cicuit probably has less than 1amp running through it 
Bin the relay, stick ign 12v straight to the light and then run the earth lines too the m/c switch and handbrake switch. simple as that.
Chris
[Edited on 29/12/09 by chris mason]
Because then his light would be on all the time, he wants it on when the fluid is low (I think).
[Edited on 29-12-09 by flibble]
quote:
Originally posted by rachaeljf
Speedy, you haven't wired it right! Your diagram is nothing like my description or flibble's diagram.
(doh)
quote:
Originally posted by flibble
Because then his light would be on all the time, he wants it on when the fluid is low (I think).
[Edited on 29-12-09 by flibble]
quote:
Originally posted by chris mason
quote:
Originally posted by flibble
Because then his light would be on all the time, he wants it on when the fluid is low (I think).
[Edited on 29-12-09 by flibble]
no it wouldn't lol
the circuit is only complete when the fluid is low or the hand brake is on with the ign on.
Chris
quote:
Originally posted by speedyxjs
quote:
Originally posted by chris mason
quote:
Originally posted by flibble
Because then his light would be on all the time, he wants it on when the fluid is low (I think).
[Edited on 29-12-09 by flibble]
no it wouldn't lol
the circuit is only complete when the fluid is low or the hand brake is on with the ign on.
Chris
My stupid one works the other way round. The circuit is complete when the fluid is high.
I did it the way you said Chris before i put the relay in and the light was on when the float was in the reservoir and went out when i took it out. I
know this is complicated (and it doesnt help that i am easily confused when it comes to wiring 
)
Speedy, is the other end of your warning light provided with 12V or an earth?
Your diagram suggests your warning light has 12V at the other end, rather than an earth as flibble and I assumed. If you do indeed have a
"live" warning light, try connecting the m/cyl 12V where you currently have ign 12V connected at the relay. Delete the ign 12V supply to the
relay as it isn't needed.
You may need to try the warning light wire on one or other of the lower horizontal terminals to get it to come on when desired.
Whichever way you wire the light, you shouldn't have both of those lower horizontal terminals (87 and 87a) connected to anything, only one or
t'other.
The other side of the light is earthed atm. Will try that tomorrow.
Cheers
quote:
Originally posted by speedyxjs
I did it the way you said Chris before i put the relay in and the light was on when the float was in the reservoir and went out when i took it out. I know this is complicated (and it doesnt help that i am easily confused when it comes to wiring
Ok, flibble's diagram is the one to use.
Cheers R
quote:
Originally posted by chris mason
quote:
Originally posted by speedyxjs
I did it the way you said Chris before i put the relay in and the light was on when the float was in the reservoir and went out when i took it out. I know this is complicated (and it doesnt help that i am easily confused when it comes to wiring
Without seeing your float switch it's hard to say what's going on without making you sound daft
so if you got it working i'll leave it at that. but please tell me this isn't a universal m/c switch or a sierra one, other wise your doing something wrong
Chris
quote:
Originally posted by speedyxjs
As you all probably know by now, my master cylinder provides a 12v supply when the fluid level is ok rather than the normal providing a 12v supply when the level is low.
quote:
Originally posted by 02GF74
quote:
Originally posted by speedyxjs
As you all probably know by now, my master cylinder provides a 12v supply when the fluid level is ok rather than the normal providing a 12v supply when the level is low.
no it does not.
the master cylinder will have a float with s contact that will make/break a cricuit.
there should be 2 (or 3 on sierra master) contact on the cap.
if the master is full i.e. float is at its highest, is the circuit complete or not?
and to check, likewise if the float is at its lowest i.e. empty, is cuircuit complete or not?
disconnect all wires from the cap and check circuit with multimeter.
then we can come up with circuit for the correct scenario.
AAAAAAAAAAAAAAAAAAAAAAAAAHHHHHHHHHHHHHHHHHHHHHHHHHHHHH
ok; so open circuit when fluid is low.
most unfortunate - you will need more than just a lamp to make it work..... hence presumably why the mention of relays.
simplest would be to put the swtich across a 6 V lamp* so that the lamp is shorted out when closed.
it would need a resistor to limit the current, something like this:
* or use a LED.
Rescued attachment lamp.jpg
Cheers 02GF74, will try fibbles diagram but if that doesnt work, il do it that way
How many Locosters does it take to fit a relay??
Fibbles diagram is spot on. 02GF what the hecks that.
Cheers,
Bob
[Edited on 30/12/09 by splitrivet]
yep.....fibbles diagram is spot on - apart from you need to fit a fuse, then if you make a mistake its just a case of changing blown fuse rather than more wiring damage
quote:
Originally posted by splitrivet
How many Locosters does it take to fit a relay??
Fibbles diagram is spot on. 02GF what the hecks that.
Cheers,
Bob
Well i wired it the way fibble said and it works fine except the relay doesnt change back and switch the light off when i the circuit is complete again (reservoir full)
Are you sure that your reservoir cap is working correctly?
As said previously - most caps I've seen make the connection when the level gets too low. Generally this makes the wiring so much simpler, a
trick that most car manufacturers wouldn't have missed.
Speedy you really need to meter out your cap/switch. Something as simple as this circuit should only take at the most an hour to sort out. If
you're struggling here then you're gonna be lost when it comes to the column switches etc.
I don't mean to be nasty or anything but if the last lot went up in smoke then perhaps you don't fully understand circuits enough. You may
need to/should get someone else in to do it. The last thing any of us want is a post from you showing a burnt out shell after all your hard work.
Sorry if that offends you but we all have limits.
[Edited on 30/12/09 by omega 24 v6]
Yeah i know what you mean. I dont need to worry about the column switches. Iv done them already
This is the last thing left. Iv had a good look at it but it seems to be working correctly. I too would have thought it would make more sense to make
it the other way but the only thing i can think of is if the wires connected to one of the ECU's on the donor car (it had a few!).
It does seem stupid how something this small could be so hard to figure out.
Does anyone know what size the reserviour cap is on a sierra MC? If that fits i think it would be soooooooo much easier to just fit one of them
quote:
Originally posted by speedyxjs
Does anyone know what size the reservoir cap is on a sierra MC? If that fits i think it would be soooooooo much easier to just fit one of them
quote:
Originally posted by David Jenkins
Probably not such a daft idea - most brake systems were made by only 4 or 5 different manufacturers, so I wouldn't be at all surprised if the caps from some other cars would fit.
quote:
Originally posted by 02GF74
quote:
Originally posted by David Jenkins
Probably not such a daft idea - most brake systems were made by only 4 or 5 different manufacturers, so I wouldn't be at all surprised if the caps from some other cars would fit.
take sa look at asn Easibleed kit and you will see that the above is true i.e. not that many variation in caps.
I can measure the sierra one tomorrow if noone else gets round to it.
reservoir neck diameter = 45 mm
too difficult to measure thread pitch since there are about 1 - 2 threads on the neck.
Ford 74470340 is moulded on the switch assembly.
now my fingers smell of brake fluid 
quote:
Originally posted by 02GF74
reservoir neck diameter = 45 mm
too difficult to measure thread pitch since there are about 1 - 2 threads on the neck.
Ford 74470340 is moulded on the switch assembly.
now my fingers smell of brake fluid