The Dark Side: V8, V6 & 4 Cylinder Engine Conversions and related radical modifications (brakes, transmission, suspension, drivetrain) for MGB, MGA, Midget and all other MG models. Purists beware!
Ok i found out the hard way that I need to redo/update my engine bay wiring. I currently have 4 new ones from BMC but as I am dragging my feet I was wondering how many does everyone us. I think that I need to order two more-here is what I am think, and only want to do this once- motor 2.8v6 MPFI 1986
Inginition switch
starter
rad fan
fuel pump
new heated O2 sensor
heater fan
have two already for aftermarket high output headlights
The heated O2 should not need one... I believe. Check the voltage required to heat it and times that by two. I do not use a heated O2 sensor but have heard of others doing this because the headers in some systems cool down enough that it plays with unheated O2 sensors. I have never found any of our cars to run funny so I am not suggesting anyone goes out to install them just because they can be an improvement in a minority of cases.
The fan, if its a 2 speed fan does run faster and better if installing one on the 'high' speed section only. The resistance in the system on the lower setting is part of how they slow the system down. Not intentionally necessarily done this way but it is a way they built it in.
-BMC.
more great info thx Brian.
BUT why just the high speed side, I am going to take the resistior from my 79 and use it on my 75 so why just the high speed side
You might want to look at ones for the wiper motor, headlights and horn.
I say the high side because its rare to run an MG on the low side and the built in resistance of the low side slows the motor down. True it does not help save the switch, but if your going to only run the low side 15% of the time, its not going through too much work for too long.
-BMC.