MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGA - Two Questions #2

When I turn on my left flasher,all four of my mga running lights flash in unison (like 4-way emeergency flashers). Any suggestions on how to fix this would be helpfull. To the best of my limited(and it is )electrical knowledge ,all wires are connected and secure. headlights work,parking lights work,brake lights work,etc.
Thanks Gordon
Gordon Harrison

It sounds like either your switch or the flasher contol is wire incorrectly. Is this a new problem, or was this following some work with either of the components? I'd check the switch first (not the likely cause, but possible and easy to verify) then the flasher control (the one with the cover and coils/points), which is my guess for the problem. Other than that, is it possible that the lights themselves were wired incorrectly? In this case, I can't think of an easy way that all four corners would flash if you used a factory harness.
Kemper

It is a new rebuild with a new Moss harness. I know barney has a page on testing the direction relays but just reading it scares me. The switch has been aprt...cleaned an reassembled and appears OK. I thought i may hace crossed something up but can see where. All wire connections (rear lights ..headlights..parking lights ) match the wiring diagram. gordon
Gordon Harrison

When I serviced mine, I isolated each wire to confirm which corner it went to. My harness is original and most of the wires are grease and/or dirt colored, rather than "green w/ red stripe", so following the diagram was always possible. I think I'd take it apart again and take it one wire at a time, testing the wire path continuity to each corner. You could apply power (with a charger) on the wire to the light (disconnected from the flasher unit) to ensure its path. Then activate the turn switch. With a test light, find the flasher unit output that's flashing and connect the appropriate wire. Repeat for the other corners.

Do all four corners flash regardless of which direction the swithch is turned?
Kemper

Maybe I should mention that my POR is a 1500.

Before you take it apart, take the cover off the relay and activate the switch in each direction. If the switch is wired correctly, different coils should activate depending on switch position. If all of them activate at once, it's between the switch and the relay.
Kemper

Poor grounds can cause backfeeds. A bad 1157 (dual filament) bulb that is shorted between input terminals or a single filament bulb installed where a dual filament bulb goes can connect as you describe.
R J Brown

Does the same happen when you set the switch to right?

The flasher is common to both pairs of lights. The indicator switch determines which pair are used.
Dan Smithers

I checked the bulbs last night and they are all dual filament. I get a loud clicking noise out of the directional relay. Brake lights work.Parking lights work although it seems the front and rear passenger side are brighter than the driver side. I took the flasher apart and checked everything OK. Wiring for the diectional relay,voltage relay and fuse box are checked and correct. Flasher unit wires attached properly.

Very frustrating because I need to have the car inspected next week or I won't be able to have it at Stowe this year.Thanks for the help
Gordon Harrison

Do you have the bulbs in the right way round?

It sounds like an earthing problem, check the earthing on the dimmer side of teh car.
dominic clancy

Run a jumper wire from the dim light(s) housing to a known ground and see if they get brighter or check continuity to ground for the bright and dim sides.

I would take a test light and with the indicator switched, test each terminal to see that it is functioning properly (one side flashing at a time). This would eliminated the corner lights and wiring from the equation and would test the switch and relay function. If they test OK, I would disconnect the wires at the relay and apply 12V to each corner circuit to see if each light is isolated.

FWIW, when i had an indicator problem on my '58 and needed an inspection, I went to a shop with younger guys. When they asked me for right signal, I gave him the hand signal. He said, "You should have a flasher". Before I could respond, another guy in the back said, "Those things don't have turn signals". The guy put the sticker on and I left.
Kemper

>>test each terminal to see that it is functioning properly<<

"It" being the relay.
Kemper

If one side is brighter then it could be a poor ground. If a bulb is not grounded it can backfeed through the other filament and ground by lighting the filaments in the other circuit. Are both filaments lighting up? when only one should.
R J Brown

This thread was discussed between 10/08/2006 and 11/08/2006

MG MGA index

This thread is from the archive. The Live MG MGA BBS is active now.