mgs
[Top] [All Lists]

Re: [Mgs] Emergency brake light & Hazard light problem

To: <DMatt21502@aol.com>, <mgs@autox.team.net>
Subject: Re: [Mgs] Emergency brake light & Hazard light problem
From: "Paul Hunt" <paul.hunt1@blueyonder.co.uk>
Date: Tue, 21 Aug 2007 16:55:02 +0100
1.  The brake pressure failure shuttle has probably moved far enough to one 
side to trip the warning switch, either because there is a leak on one 
circuit, or the brakes were bled but the shuttle valve wasn't re-centred 
afterwards.  It *could* be the switch, but you should eliminate the other 
factors first.  If there are no visible leaks you need to rebleed the 
system.  If you have recently bled the brakes, didn't recentre the shuttle, 
and don't know which circuit you bled last you will have to bleed first one 
circuit then the other until the light goes off.  Do this by having someone 
apply pressure to the pedal and watch the warning light (ignition on, 
handbrake off) while you open the bleed valve just a fraction and bleed very 
slowly.  If the light doesn't go out quite soon you will have to try the 
other circuit.  As soon as your assistant shouts that the light has gone out 
close the bleed valve immediately.  If you are too slow the shuttle will 
move past the central position and operate the switch from the other side, 
and you will have to repeat the process on the other circuit.

2.  There were two different turn signal flashers according to year, one up 
to 67 and one after.  There was only one hazard flasher.  9FL is the hazard 
flasher, which may also be labelled that it can flash 4*21w + 6w.  Turn 
flasher units can only flash 2*21w + 6w.  The hazard switch when turned on 
should *disconnect* 12v (ignition switch on) from the green wire at the turn 
flasher unit, this prevents the ignition and fuel pump being live when they 
shouldn't be.  The hazard flasher should have 12v on the brown but not on 
the light-green/brown all the time the hazards are *off*.  When the hazards 
are on the light-green/brown, green/red and green/white turn signal lamp 
wires (and light-green/purple tell-tale wire where fitted) are all connected 
together and the load of the lamps starts the hazard unit flashing 
on-off-on-off after a short pause in the off state.  With the hazard switch 
off and the ignition switch on the turn flasher should have 12v on both the 
green and light-green/brown wires.  When the turn flasher switch is operated 
the turn lamps that side should come on immediately, then start flashing 
off-on-off-on after a short delay.  While this is happening you should be 
able to see 12v flashing on and off at the green/red (LHS) and green/white 
(RHS) wires depending on which side the turn signal switch was moved to. 
Sounds like you have something screwy in the wiring, or possibly the switch. 
If you plot things through logically using the above you should be able to 
suss it out.

PaulH.

----- Original Message ----- 
> Problem 1     The emergency brake light continues to be on even when the
> handbrake is  off.
> Problem 2      Used my emergency flasher for the first time recently and 
> it
> will only  work if I turn on one of my turn signals while the emergency
> flasher
> switch is  on. 
_______________________________________________

Edit your replies

Mgs@autox.team.net
http://autox.team.net/mailman/listinfo/mgs

<Prev in Thread] Current Thread [Next in Thread>