i just completed the installation of the above wiring harness in my 1959 bn6. most likely most of these abbreviated harnesses are very similar. the speedway harness i bought was made by EZ wiring. as i was testing circuits i could not get the brake lights to work. i called speedway tech and they did not have a clue and did not seem to know who made the harness branded under their name. after trying several ideas i googled the harness part number and came up with the manufacturer...EZ wiring website and listed was their technical service number. after about two minutes explaining my problem of no brake lights and how the healey trafficator worked, the technician told me exactly what to do. a trip to radio shack for 4 diodes and 30 minutes later of wire changes and soldering i had brake lights...... a very easy fix.....so for information the speedway 12 circuit harness will not work with the healey turn signal switch without modifications to the harness that are not mentioned in the instructions.
Thank you. :)
I will likely use the harness from Advanced when I get that far, for that very reason (they know these cars).
Do you have a picture, diagram or explanation of where the diodes needed to go?
That might help someone in the future as well. :)
Advance Autowire is the way to go.
http://www.advanceautowire.com/
i did check the advance site and that is an impressive harness. i like the seven relays to deal with perhaps needed switch protection for lighting, etc. the instructions and fuse block schematic are very complete. i was not aware of this product when i bought the speedway harness. i did notice that they show no prices so i cant compare. the speedway harness is easy to install and seems to be a quality product. and, you can get help from EZ wiring. i dont know how to add a drawing......but the basic change is to use the third brake light wire to provide power for the brake light/turn signal filament to each of the rear bulbs. add a diode to each of the brake power wires before the splice . then place a diode into each rear turn signal power wire.....upstream from the spliced in brake wire. the diode part number is 276-1661 at radio shack. four diodes are required.
Thank you. :)
Hello,
This has probably been addressed before, so please excuse me if it's already been covered. I seriously want to install the Advance Autowire in my '78 mgb coupe over the Winter. I'm sure the interior will have to come out, (and probably the dash etc.). This is addressed to someone who has completed the upgrade: Did you pull your engine, or just try to work around it.
Thanks