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MG MGB Technical - Turn signals work -ignition switch not on ???

I'm in the process of bringing a '78 B back to life. The PO had the car practically in pieces and in had installed a Moss ignition switch that didn't use the slate or pink wires (key buzzer and fuel shut-off ?)

Anyway, after swapping wires around to find the right combination, the turn signals work with the key in the OFF position. Any ideas as to what the problem may be. I searched the archives and couldn't find anything on this problem. The fuel pump ticks in the second position and the car starts in the third.

After starting this thread, I got to thinking if the hazzard switch may at the root of this problem.

Any ideas??
Douglas Martin

Douglas,
If I'm not mistaken, this is normal. The turn signals should work with the key in the off position. They certainly do on mine.

In fact, the turn signals work even without the key in the ignition. If they went off without they key, we wouldn't be able to leave the hazards on and take the keys with us.

Jeremy
1974.5 MGB
J. Palgon

My hazzards work with no key, but not the turn signals on any of the numerous MGBs I've owned. Check your wiring at the fuse box. Are the right wires plugged into the right fuses?

FWIW,
Allen
Allen

Hi

Turn signal are not suppose to work without the key to "on" position. At least on the 78 and around. Is it possible that a PO used the same supply to feed the hazard AND the turn signals ? would be easy since both flashing gizmos are side by side. Hazard flasher unit is fed by a brown wire (straight from the battery) and turn signal unit by a green (through the ignition switch). Regarding the igition switch, pink wire is used for the key warning buzzer as you mentionned so not really necessary but the slate one goes to the anti run-on valve and this one can be useful.

hope this help
M Gaudreault

Douglas Martin -

Turn signals get power from the green circuit. Hazards get power from the brown circuit.
Make sure your fuse box is orientated correctly. The top two fuses are bridged and are used for the lighting circuits. The bottom two fuses are independent.

Original wiring for ignition switch

white - switched on in #II position (supplies power to the fuel pump and the green circuit)

white/green - switched on in #I and #II positions (radio)

white/red - switched on in #III position (provides power to the starter relay)

black - ground

slate - switched on in #II position (not sure about this one, it goes to the anti-runon valve only)

purple/pink - I believe it is always hot, goes to seat belt module to let you know you left your key in the ignition, connects to a blue switch in the drivers door jamb

brown - supplies power to the ignition switch

If you don't have one, a wiring diagram is available at www.advanceautowire.com courtesy of Dan Masters.

Make a couple of enlarged copies, one for reference and one to make notes on while you are trouble shooting. I'm assuming you have a test light and/or meter.

J. Palgon -

I checked the wiring diagrams for your car ('74.5).

Turn signals should work only when the car is on. The turn signals get power from the green circuit.

Hazard lights should work with the car on or off, with the key in the ignition or not. They get power from the brown circuit. You may want to make sure your hazard switch is wired correctly.

Kimberly Petretti

Thanks for all the help. I'm trying to get this sorted out. I discovered last night that the hazzard switch is a "dummy". I pulled the switch and found that the "guts" are gone. There ought to be an application process before allowing people to by these cars. I find that most non-enthusiast PO's screw things up rather than fix things properly. I've never seen so many stray wires hooked-up willy nilly. I guess that stupidity is not a crime, but it should at least be painful.

DM
DMartin

Wiring diagrams are available online at <http://www.advanceautowire.com>. Make a couple of enlarged copies, one for reference and one to make notes on while you inspect, check, and correct any of the PO's "improvements, repairs".
Kimberly

The turn signals should *never* work with the ignition off, or when the hazards are on regardless of whether the ignition is off or on. However the *hazards* should work regardless of whether the ignition is on or off or without the key being in the lock at all, of course.

The turn signals are powered from the green circuit, which comes via the 2nd fuse up in the fusebox from the white circuit, which powers the ignition. Whilst it is possible to install the fusebox upside down and have the ignition and turn signals powered all the time, if the turn signals work all the sime but the ignition works correctly then they have been connected incorrectly, somewhere or other.

What do the fuel gauge, reverse lights and brake lights do with the ignition off?
Paul Hunt 2

This thread was discussed between 06/06/2006 and 09/06/2006

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