MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

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 - Mga parking lights

My driver side flasher light was not working. I went through the whole system and now it works.

The brake lights...headlights..flashers...dash lights...map light all work EXCEPT now the parking lights have conked out.

Is it possible that, because the pigtail wires on the driver side parking light, are both black colored wires that I just need to switch the two connections and my lights will work.

I do not want to mess up what is already working.

thank you
1957 Mga Coupe
Gordon Harrison

Check all earthing points first - the usual problem!
Those connections were made in the factory many, many years ago!
Barry.
Barry Gannon

Gordon

STOP

Before you start switching cables around test which one has 12V and which is ground. Putting a 12V feed directly to ground will burn out your wiring harness as the lights have no fuse
Dominic Clancy

Gordon
I agree with Dominic 100%,
a lot of years ago I decided to connect up the side-lights that were built into my new Wipac headlamp units.
One side lit up fine but when I connected the second side, all that happened was a strange whining sound and a strong smell of burning!
By the time I got to the battery cut-off switch, the whole of the front section of the wiring loom was melted from the light unit to the fuse box!
It cost me £500 to fix the damage!
Apparently,the DPO,had wired it so that the black was live! and so I had connected the supply direct to earth.

I ALWAYS check a wire with a meter now before I connect anything. I also disconnect the battery and instead, connect up a low output battery charger to test things.
Cheers
Colyn
Colyn Firth

I noticed last night, in the dark garage that the passenger FLASHER light shines MUCH dimmer than the driver. All my lights work except the front and rear parking lights.

I saw an online picture of an Mga front parking light unit. There was a RED WIRE on the pigtail connector. Mine has to black wires , so I am not sure which is for the flasher and which is for the parking lights.

Coming from the grill area is the red and pale green wires for the light and a black ground wire , which I have attached the black to the connection on the lamp base. .

What has me confused is how do I tell which of the two black pigtail wires goes to the RED power wire. If I get that right I assume the parking lights will then work also.

Would it be OK, to reverse the current pigtail connections with TWO FUSED JUMPER WIRES. Worst that could happen is I will blow one of the fuses or solve the problem.....NO
Gordon Harrison

Gordon,
DON'T connect anything on your lighting circuit and hope that a fuse will blow if you make a mistake.

If your MGA has the original type wiring loom, then YOUR LIGHTS ARE NOT FUSED AT ALL and the result of a short circuit could be a burnt out wiring loom or a fire!

After my lighting wiring melt down, the loom was so badly melted that when I took it to Bob Wests to have it fixed, he wouldn't allow my car inside his workshop until he removed the battery in case it caught fire and burned out his car collection.

After that experience, I fitted a separate fuse into the lighting circuit to prevent it from ever happening again.

Why not just use a digital meter to check which wire is live when you switch the sidelights on at the dashboard?

Colyn
Colyn Firth

Is your car a 1500 or 1600?
Dominic Clancy

Domenic and Colyn, Thank you for your advise. Domenic it is an all origional 1500

I think we may be getting away from the main question.

It is in regard to the pigtail wiring that is inside my front parking light. The origional ones had two wires (one red one green) but my pigtail wires (inside the light unit) are both black.

Currently the main wire harness ground wire has been connected to the rear of the lamp socket. One of the pigtail black wires is connected to the main wire harness RED (POWER SOURCE) wire and the other to the GREEN.

All of the FLASHERS now work, except the front driver flasher is very weak / dull. And the none of the parking lights work.

I feel that all I must do is to reverse the connection
of the RED and Green wires and all should work. but as Colyn said I do not wish to burn up my main wire harness. I think I should just go out and buy a new pigtail unit which has the proper colour wires.

Colyn, I will take your advise and fuse the main lighting wires to prevent future trouble.


Gordon Harrison

I asked the question to make sure I could suggest the right approach.

You don't have one problem, you have two! And they should be addressed as two separate issues.

a) The weak direction indicator and
b) non operating parking lights.

a) may well be resolved by swapping the wires, because the bulb has a 5W and a 21W filament, and swapping the wires may swap to the brighter filament. If this was the only issue the parking light on that side would be much brighter and all the lights would work

but a) may also be caused by a weak ground connection, which you can test using a meter. I would check this first. A weak ground should not cause all four parking lights to fail

b) is not necessarily related to a), and if all four parking lights are not working, I would first check if you have 12V at the red wires in the connectors by the starter switch. If no 12V at that connector, the problem is under the dashboard, and a red wire has come adrift from the light switch.
If yes, check the other connectors in the red wires at each bullet connector and resolve until your parking lights work.
Dominic Clancy

You may want to check the switch and wires at the switch to make sure you are getting good contact for the parking lights.

Jim
JL Cheatham

I switched the two pigtail wires and now I have the following;

FLASHER LIGHTS, DASH BOARD LIGHTS,HEADLIGHTS,BRAKE LIGHTS (when the brake pedal is pushed),MAP LIGHT, all working. All light bulbs shine bright and strong. The only lights not working are front and back parking lights and the license plate light.

There is power at the ignition switch on the RED wires and at the light switch. I have not checked the voltage at these wires or the connector but will do so tomorrow. The connections all seem very tight and secure.

If I have 12 volts at the ignition connector, is it OK to use a test light for the rest of the RED wire connectors or do I need to check the voltage at each connector.

As you can see, electricity is not my strong point so I really appreciate all your help and patience.




Gordon Harrison

Great, so I was right about a).

Now to b): The fault is quite clearly one in the red wire circuit only. If the dash lights are working, your switch is OK, but a wire has come unattached at the switch, or at the bundle by the starter switch. These are the only two points common to parking lights for all four corners. It may be that to share the red wires a bit (four of them into the light switch is a struggle) that two of them are attached to the fog light switch. When you find your errant red wire, this may be the good place to reinstall it.

But I am a little confused by you writing there is power at the red on the ignition switch - there should be no red there, just two white and two brown / blue. See the attached picture from Barney (Ignition switch is I top left) - are you getting the light switch mixed up with the ignition switch when you are on your back with head under the dash ?!




Dominic Clancy

I think you are right and I confused the two switches. I will look at them later this week as on Saturday I was working on something else and my ladder broke. I fell 6 feet flat on to a concrete slab. I landed on my ass / hip and slammed by head. I am OK but I ache a little. I will give it a few days and check it out.

I really appreciate your help.
Gordon Harrison

OK
The light switch has power at both terminals that are red and no power at the blue terminal. With the light switch ON should there be power coming from the single red wire on the light switch to the multi-connector near the starter switch.

I thought I had fixed it because when I checked the red wire coming from the light switch to the multi-terminal at the starter switch, it seemed loose. Resetting it securely did not change anything. Parking lights still do not work.

It is important to remember that all wiring was working until the driver flasher stopped.

Gordon Harrison

Hi Gordon

Again, the fact that your flashers weren't working as expected has NOTHING to do with the fact that your parking lights don't work. Ditch that idea, and you will perhaps have a better chance of fixing the parking lights.

Then you need to look again closely at the switch - this is shown in the wiring diagramme as L .

There are three terminals - these are wired as follows

Terminal A (Marked on the back of the switch):
Brown with a blue stripe (NU) which is the live terminal. This should have 12V whether on or off.

Terminal S1 : FOUR red wires on the remaining terminal. One of these runs to the foglight switch, one to the dimmer switch, one to the map light switch and one to the red cluster at the starter switch. These should be live on the first pull of the light switch.

Terminal S2 : one Blue (U) wire, which routes to the dip switch and is the feed for the headlamp circuit. This should be live when the headlight switch is pulled out and twisted then pulled out again. Ignition on or off makes no difference

So there should be only one terminal with red wires, and you seem to be missing the Brown / Blue wire, which should mean that your headlights don't work either. Or the wiring has been done some other non-standard way. Where are you switching on the headlights if they are working now?





Dominic Clancy

PROBLEM SOVED

When I wired the car I put an inline fuse on the RED wire. Instead of cramming 4 wires into one connector, I used a double bullet connector for TWO RED wires and then one FUSED RED, plus the other red wire to the light switch. It must have blown when I shorted the flasher unit.

As I do not spend much time under the dash board I forgot about the fuse. 35 AMP

I did learn that the signal lights are powered by the Green wire, s o I came away with a little more knowledge that I had before.

Thank you Domenic. You were a big help.
Gordon Harrison

This thread was discussed between 02/09/2020 and 14/09/2020

MG MGA index

This thread is from the archives. Join the live MG MGA BBS now