mg-t
[Top] [All Lists]

Re: [Mg-t] TF Blinkers & Brake Lights

To: gunnellj@athenet.net
Subject: Re: [Mg-t] TF Blinkers & Brake Lights
From: Dave and Liz DuBois <ddubois@sinclair.net>
Date: Fri, 17 Apr 2009 22:57:32 -0700
John,

Larry is correct, the standard Lucas turn signal switch self cancel 
function is strictly mechanical and has nothing whatsoever to do with 
the turn signals working.  You can use a plain old single pole, double 
throw toggle switch from Radio shack for the switch - you just have to 
remember to cancel the signals yourself by flipping the switch back to 
the center. 

Like Larry, I suspect that the problem you are experiencing is probably 
centered in your turn signal relay as much as in the switch.  Taking 
your two problems (brake lights and turn signals) and deal with them 
individually.

First the brake lights.  Jack the car up, turn the ignition on, crawl 
under the car and short between the two terminals on the brake light 
switch and see if the brake lights come on.  If they do, the replacement 
switch is bad (not surprising, the replacement switches are junk - more 
on that later).  If the brake lights don't come on it is time to look at 
the turn signal relay (which we were going to do anyway).

Again, with the ignition turned on (disconnect the primary wires from 
the coil while you are doing this so you don't fry the coil and/or the 
points), jumper terminal 5 to terminal 7 on the relay while having 
someone step on the brake pedal.  If the brake light on both sides come 
on, then one of the  normally closed contacts in the relay is the 
problem.  Now jumper terminal 5 to terminal 3 on the relay while your 
helper steps on the brakes and see if the other side comes on.  If it 
does then both normally closed contacts in the relay need work.  If you 
still don't get any brake lights with these two tests, then you have 
wiring problems going from the fuse block to the brake light switch.  
(note:  regardless of the outcome of all of these tests, you are going 
to need to make up, or purchase a brake light relay/arc suppression 
circuit and install it or the replacement switch will fail withing a 
very short time.  See the article, Brake light Relay in the Other Tech 
Articles section of my web site at: 
http://homepages.donobi.net/sufuelpumps/ ).

The next thing to do is to wire the new toggle switch that you got at 
Radio Shack (or where ever) with the green wire going to the center 
terminal, the  green/yellow wire going to one of the outside terminals 
and the green/blue wire to the other outside terminal.  With the 
ignition on, see if the turn signals work with this switch.  If they do, 
install the switch until you can get an original switch that works.  If 
they don't, then the relay needs to have the contacts cleaned and 
adjusted so that they will work correctly.

If you are still having problems with th e tests, the results or you 
can't get the relay to work properly, e-mail me directly at 
SUfuelpumps@donobi.net and I'll see if I can walk you through the problem.

Cheers,
Dave
_______________________________________________

Support Team.Net  http://www.team.net/donate.html

Mg-t@autox.team.net
http://autox.team.net/mailman/listinfo/mg-t

Archives at http://www.team.net/archive

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