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MG MGA - Me Again..electrical problems

Sorry for all the questions in the past year, but with the help of this group I've made great strides in taking care of many minor problems with the "almost" restored '59 roadster that I purchased on E-bay last fall. I've got new radial tires, fixed the bothersome gaps in the doors, solved the front end "shake" problems, and fixed the distributor. Now I've got another to work on. The lighting is all messed up. The car has a new wiring harness. I've got a schematic a manual, and a test lamp, but have not attempted any diagnosis yet. Here's what I've got...
With the car running and the headlights off, both brakelights work, the right front and rear turn signals work, the turn indicator on the dash works, but when I turn on the left signal, both left and right flash in the front and rear.
With the car running and the headlights on, both running lights work, both tail lights work but appear bright. Applying the brakes makes no difference in the brightness. The right front turn signal works, the left does not. Neither the right or left rear turn signal works.
The headlights work ok. Both brights and dims.
Before I start finding my way through this, does anyone have any words of wisdom? As usual, anything is appreciated.
Jerry
Jerry Murphy

Jerry, it sounds like the wires at the tail lite bulbs are backwards. when you turn on the running lights on, the brake/blinker (brite) side of the bulb lites. When you step on the brakes the running lite (dimmer) side lites, but you can't tell. If you still have problems with the blinkers after fixing the above (I think you will) check the wiring at the 8 wire relay box on the firewall, the flasher and the turn signal switch. Good luck, John
J.H. Hall

Jerry,

In addition, remove the cover box of the the relay and clean the points lightly with a points file. Available at NAPA and others. Additionaly not only verify the the relay is moving but determine by visual inspection that the point sets are actually making contact. I needed to bend one of the arms a bit to make one set of points connect--even though they were moving.

Paul Hanley

Paul, he may not have a relay if it's a 1959 1600.
Joe Cook

With the signals and lights miss-wired, you may also have some other mistakes as well. I'd get an enlarged schematic and check the wiring, system by system, until I was sure everything was correct.
R. L Carleen

Jerry,

Just don't let all these little glitches get you down. Once they are all sorted out you will have a GREAT car to drive! Also know that you are not alone. I have had ALL of the same problems with my '56. Sick as it may sound,I think all of these gremlins make the MGA more fun to own. There is real satisfaction in overcoming the leaks, overheating, poorly aligned doors, and Lucas demons and all the other common bugs. Anyone (with the bucks) can own a '56 T-Bird and with regular maintenance it will run like a '50's Ford. MGAs are for the adventurous.

Frank
Frank Nocera

I'm sorry guys, I should have stated that it is a "59 1500. I'm following the replies with interest.
Thanks!
Jerry Murphy

One of your US suppliers is advertising very colourful MGA wiring diagrams on Ebay over here: http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=36089&item=7928673374&rd=1

Anyone bought one? Any good?

Steve
Steve Gyles

Jerry,
I agree with JH that the wires to the tail lights might be connected to the wrong filimants of the bulbs.
You should be able to tell by the wiring diagram color codes. I also verified it by having the car wiring disconnected from the tail light and applying 12V to the terminals of the tail light/ brake turn signal to determine which terminal is for which. Also and very important check all of the ground points for the tail light assemblies, as well as headlight and front parking/turn signal lights to make sure there is not pain under them and they have a good clean connection.
If you find trouble you may be wise to check all the ground points on the car.
This can cause some very STRANGE and unexplainable things to happen as the voltage tries to find a way to ground. It doesn't even have to be a bad ground in the area where the symptoms are. I had a somewhat similar set of bizarre turn signal brake light problems when I was finishing up my 1500 2 years ago. It was a bad ground on one of the taillights. Sometimes all 4 of the lights would flash etc.

Ralph
Ralph

Bring your car to me in the UK, I'm sure I can sort it out, the wiring and colours are simple. It sounds as if you have some connections crossed and an earth problem, have you put the correct bulb in the rear lamp? I've seen single filiment bulbs wedged in twin filiment sockets! This could cause your rear lamp fault As already mentioned, it could be the relay
Terry Drinkwater

This thread was discussed on 20/10/2004

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