Ford Mustang Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
240 Posts
Discussion Starter #1
So I recently swapped the worn aod to the t5 and now the brake lights stay on all the time...I unplugged the connecter at the brake light switch and they turned off...from my experience I would need to replace the switch and on my 1968 ford truck, the brake light switch was that round switch with the plunger on it attached to the brake pedal...the one with the vacuum line going to it...can anyone tell me what that is, or what it does? Thanks
 

·
Registered
Joined
·
831 Posts
I am confused. Are you asking about your Mustang with the T5 or your 68 truck with the vacuum hose attached to the brake light switch?

You did not state which year Mustang you have, but the Fox bodies all use an electric brake light switch, not a vacuum actuated one. How did you mount the clutch pedal for the T5? Did you rig something up, or did you get the stock mount? Better yet, take a picture if you can and post it.
 

·
Registered
Joined
·
240 Posts
Discussion Starter #3
Im talking about an 89 5.0 Lx, it was originally an automatic but I bought an entire swap kit for 725 which included the new pedal assy. After reading and doing research I realized the brake light switch is electric and not vacuum actuated but on the 89 mustangs brake pedal there is also some sort of switch that ir round and long that has a vacuum line attached to it on one side and on the other it a button that is actuated when the brake pedal is pressed. It looks identical to a brake light switch on my 68 ford but now I know it is not it..
 

Attachments

·
Registered
Joined
·
831 Posts
I had an 89 LX 5.0 many years ago, and for the life of me, I don't recognize that switch. That is not saying much though considering my poor memory! :)

Could that switch have something to do with the automatic trans you removed? I had a T5 in my car, so that would explain me not remembering it. I am unsure how that switch would work if it is vacuum operated. Does it vent the vacuum supply? If that is so, then it would hiss each time you press the brake.

Can you confirm that it is in fact attached to the vacuum system, and not merely missing its wire?
 

·
Registered
Joined
·
240 Posts
Discussion Starter #5
It has a large vacuum line that apparently goes to the booster that is connected to the side opposite the yellow button...I was thinking it has something to do with cruise control, maybe a deactivation or something but I have no idea, if the car doesn't need it then im not gonna worry about it but if it does then i need to know what it is...actually i would like to know either way....and now that I think of it, the switch was on the aod pedal assy as well, so it does belong there...I think
 

·
Registered
Joined
·
831 Posts
I'd look up a vacuum diagram for the car and determine what that is once and for all. I am at a loss as to what it is.

With that switch out, you will have a vacuum leak that you'll need to deal with.
 

·
Registered
Joined
·
240 Posts
Discussion Starter #7
I appreciate your input, hopefully someone will be able to chime in and help me out...oh by the way, im jealous...im in love with your car...
 

·
Registered
Joined
·
240 Posts
Discussion Starter #8
To give you the back story is that I bought the car in a complete mess, had it painted and the body work done...2k later and she looks like this, acquired the wheels from my brother who has a big block 91 fox, bought some tires and the 5 lug conversion along with the t5 swap and here I am...along the way, the pig tail for the headlight switch burned up so I replaced that and now I have lights....great thing, for me anyways, now I have to figure out how to wire up the turn signal switch because 7 of the way too many wires came out of the connecter and I am lost as to where they go...I just started up the car in regards to the switch pictured above and like you mentioned, was a big vacuum leak and my brake pedal faded badly so needless to say I guess it has something to do with that. On to my next project of wiring up the multi function switch....Thanks again
 
1 - 8 of 8 Posts
Top