MGB: Right Turn Signal - funky

Right turn signal turns on but just stays lit and doesn't flash. Left one works fine. If I turn on left turn signal and let it flash then turn on right signal, it sometimes flashes just once then stays on.

Can't see anything obvious in the wiring hiring (apart from prior issue). Small hole in flasher unit (relay?) mounted under the dash on the right side that got punched in there by PO. When I turn on the left signal, which works, you can hear and feel the click in the flasher unit, but no go with the right one.

I am suspecting the flasher unit unless I can pin it on something else. Not real good with electrical testing yet but assume it will be a required course of study as an old car owner.

Thanks for any guidance.

JTB

If your bulbs are all good, I would suspect the flasher also.

Or 90% of all electrical problems are ground related!!

Check t be sure that both the front and rear bulbs are both 1157s. I don't know if a 2057 would intefere with flasher operation or not, but maybe. If you get a new flasher get a #552, it's round but will still clip into the holder. 552 was the most popular flasher going for many years and is available at parts houses, mass merchandisers, just about everywhere. The brand doesn't matter the number is generic and they are all alike no matter who's name is on them.

Id look for a phantom earththat is an earth that the rightside is seeing when thereshould not be one. Had this on a mini once two connectors touching so thatthe flasher was seeing earth via another bulb. Worth checking for.

Many turn signal problems I have had in the past were due to corrosion taking place in the flasher warning switch (Hazard Switch). It's been a long time, but I seem to remember both, or maybe only one turn signal not operating and if you flick the hazard switch back and forth enough times, it will clean itself up and the turn signals will start working right again.

I'd have a hard time believing the flasher unit, since it will work with one direction but doesn't work the other direction. Either there is a bulb out, bad connection, or a bad switch.

Try the hazard switch, and see if all four bulbs light up and are the same intensity. A dim bulb is a bad sign, probably bad ground or corrosion.
If they all light, then try the turn signal again. If the both bulbs light up, then I'd check to make sure they are the right ones. If the bulb is not of high enouhg wattage, the flasher won't work.

The flasher unit has a heating element in it that will activate when it gets hot enough, causing the current to stop flowing. That current flows through the heating element and the light bulbs. The higher the current the quicker the element heats up. That is the reason why turn lamps flash faster when you plug in trailer lights without a heavy duty flasher.


dave

I can never remember that bit with the hazard switch. Brain farts I guess.

Check the hazard switch! Had to flip mine back and forth a few times today to get the right side to work. Happens a couple of times a year.. beautiful day in SW Michigan..nice top down-shake-down drive today.

I guess by now you know that both sides use the same flasher. (only two wires on it. Hazard uses a different flasher because it hs to flash 4 lights instead of two. Most likelya bad connection. You can try swapping bulbs with the other side to see if the problem moves. If not, it ain't the bulb.

If you have to flip the hazard switch to get the right side to work then it could be a connection problem on the right side. The hazard justs passes the G wire voltage through to the turn flasher. If you suspect the hazard switch remove the plug and jump the two G wires that are at the bottom together.

There is a difference between a flasher used for turn signals and a flasher used for hazard lights. They actually work backwards of each other.

Replaced the flasher, no change, then checked the bulb (which I should have done first) in the right rear (switched with left one) and it was good. There was a hole in the old flasher unit but still spent a few bucks that weren't necessary.

Will go back through everyone's suggestions this weekend to track it down. My electrical knowledge is pretty elementary so s-p-e-a-k s-l-o-w-l-y and at elementary levels for me.

Related problems which occured later: My left headlamp glows slightly but won't light completely. Could that be ground? Where the heck is the ground for the left headlight?

Also, map light turns on when I turn on the headlight switch. I moved a few things trying to get the wiring harness extension that goes to the console area out of the radio slot where the PO put it and have it come over the crossbar then by the side of the radio. Had to disconnect hazard switch, map light switch, etc. to do that. Labeled everything and put back where I got it.

Also, un-did some wire near the headlamp switch so I could move them back over the crossbar behind the dash. That was pretty simple too but nothing has worked right since I did them both so I must have disturbed something.

Will go back and re-check everything and follow your suggestions this weekend. Any other diagnostic process advice would be helpful. Thanks.

John

Sounds like you have some connections mixed up. As best I can tell the map light is not through the lighting switch (Same circuit as the clock). You had better get a good wiring diagram and try sorting through it.

It helps greatly if you can enlarge the wiring diagram enough to follow the traces. I have 300% blowups (poster size) of the original book size and it's pretty easy to see what is happening. I have poster sized diagrams for early 70's and late 70's MGB's if anybody needs one. ($12.00 shipped.)

Thanks everyone. Simpler than I thought thanks to many of your comments. Had a 2nd purple wire from the wiring harness that should have been plugged into the 4 hole connector (two from the wiring harness should be plugged into the same end of the connector) that leads (with another - third - purple wire coming out the other end of the connector) to the bottom right post on the switch. Apparently though it worked with one the second one being plugged in stopped the map light from turning on when I turned on the headlights and also fixed the headlights. Feel pretty stupid as it was one I unplugged when moving the harness and didn't tag as I thought I could remember. So much for that approach. Lot of wasted energy and emails and postings.