I am doing a carb swap on my 91 RS and trying to clean up the engine bay as much as possible. I was wondering if the brown wire which appears to be plugged into the brake system after the master cylinder served any worthwile function. Also, what does the wire harness going into the power steering system do? And what about the sensor (some sort of cooling sensor/switch possibly?) screwed into the driver's side head? Can I just unplug these and have everything function normally? My wiring diagrams are all packed up. Thanks for the answers!

James

 

The wire going to the brakes if for your brake idiot light to tell you when there a pressure difference between your front and rear brake systems. If there is a pressure difference your master cylinder is bad or you have a brake fluid leak. You should leave this connected. I dont know about the others though

 

the one going to the head is either an idiot light plug or a temp sensor(coolant)

 

I never understood the question of "My engine bay will look cleaner if I unplug this, does it do anything" If it is there it does something. Why would you just go aroung unplugging wires if your car runs fine. Not trying to rag on you too much, but come on. Think a little.

 

Does your car have a/c? If so, the wire going into the power steering system is a high pressure switch. When your turning really hard and the pressure in the power steering system goes way up it cuts the a/c till the pressure drops back down. This is so the engine does not have to work as hard.

 

383 bird-- well, if I am doing a carb swap and removing my ECM, then there will be lots of things that are "there" but aren't "doing anything", hence, if they are not "doing anything" I would like to remove them. 2 or 3 wires alone may not clean up the entire engine bay, but if I can remove most of the old TBI harness, it definitely would improve the looks of my engine compartment, and make the things that are "doing something" more accessible. And right now, my car doesn't "run fine". It doesn't "run" at all because it has no induction system. Sorry, I didn't mean to flame you, but if you had read my entire post, you would've realized what I was doing.

mech-- I thought that the coolant temp sensor plugged into the intake manifold? Could it be something else?

 

I would have replied the same way as you did. I misread and thought you had TBI amd you were just putting on a new unit. Sorry about the confusion

 

there are two coolant temp sensors, one in the intake manifold, one in the head, one of them is for the gauge, the other for the computer, i cant remember right now which one goes to the comp though hmm, i'd say leave it plugged in for now untill you get it running or follow the harness back and see if it goes to the computer harness, if so than you can lose it, if not it should go through the fire wall on the driver's side and in that case, dont mess with it.

 

Head - gauge.. intake - ECM

 

cool, thats what i was thinking but i wasnt sure so I wasnt willing to post it, oh yeah hey deadbird, I like your motto lol :lala: