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TR2/3/3A Turn signal flasher issue.....electrical is not my strong point.

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karls59tr

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I had to pull the steering wheel control head and tube out to do some repairs and stop the control head from moving. I repaired some wiring at the bottom of the tube. I replaced the flasher unit as it was working intermitedly. I put in a new Napa flasher that was identical to the one that has been in there for many years. The problem is when I put a turn signal on it will flash for a couple seconds then stop? If I press against the flasher unit I can keep the turn signal flashing! I thought I may have connected the 3 ends on the flasher unit wrong but when I press against the flasher the front and rear signal lights work correctly. The latest thing I did was disconnect the "light green"wire from the flasher at one of those rubber wire connectors about 8" from the flasher unit and the flasher continued to flash with the wire disconnected???? Any help greatly appreciated.
 
The original style flasher uses a bi-metal contact. The current passing through the contact causes the metal arm to bend from the temperature change and break the contact. The arm then cools quickly, bending the arm back to re-make contact for a second and cycle again. These units are very sensitive to the amount of current going through them. If you switch to LED lights, the current is reduced and the arm never heats enough to break the contact. Likewise, too much current (say from pulling a trailer with more lights), and the flasher flickers rapidly.

Back to your issue...it sounds like either one of your lights is not lighting to keep the unit flashing (burned out bulb), or the flasher is rated too high for the number of lights the TR3 has operating. They do make electronic flasher units that compensate over a wide range of currents. Almost all of the older, say pre-1980's, units are interchangeable as far as the electrics go.
 
CJD said:
The original style flasher uses a bi-metal contact. The current passing through the contact causes the metal arm to bend from the temperature change and break the contact. The arm then cools quickly, bending the arm back to re-make contact for a second and cycle again. These units are very sensitive to the amount of current going through them. If you switch to LED lights, the current is reduced and the arm never heats enough to break the contact. Likewise, too much current (say from pulling a trailer with more lights), and the flasher flickers rapidly.
CJD said:
The original style flasher uses a bi-metal contact. The current passing through the contact causes the metal arm to bend from the temperature change and break the contact. The arm then cools quickly, bending the arm back to re-make contact for a second and cycle again. These units are very sensitive to the amount of current going through them. If you switch to LED lights, the current is reduced and the arm never heats enough to break the contact. Likewise, too much current (say from pulling a trailer with more lights), and the flasher flickers rapidly.

Back to your issue...it sounds like either one of your lights is not lighting to keep the unit flashing (burned out bulb), or the flasher is rated too high for the number of lights the TR3 has operating. They do make electronic flasher units that compensate over a wide range of currents. Almost all of the older, say pre-1980's, units are interchangeable as far as the electrics go.
Click to expand...

Back to your issue...it sounds like either one of your lights is not lighting to keep the unit flashing (burned out bulb), or the flasher is rated too high for the number of lights the TR3 has operating. They do make electronic flasher units that compensate over a wide range of currents. Almost all of the older, say pre-1980's, units are interchangeable as far as the electrics go.
Click to expand...
 
karls59tr said:
I had to pull the steering wheel control head and tube out to do some repairs and stop the control head from moving. I repaired some wiring at the bottom of the tube. I replaced the flasher unit as it was working intermitedly. I put in a new Napa flasher that was identical to the one that has been in there for many years. The problem is when I put a turn signal on it will flash for a couple seconds then stop? If I press against the flasher unit I can keep the turn signal flashing! I thought I may have connected the 3 ends on the flasher unit wrong but when I press against the flasher the front and rear signal lights work correctly. The latest thing I did was disconnect the "light green"wire from the flasher at one of those rubber wire connectors about 8" from the flasher unit and the flasher continued to flash with the wire disconnected???? Any help greatly appreciated.
Click to expand...
I had a problem with my 1972 mgb, turns signals flashed slowly when running, and not at all with just the key on. I changed to an OEM flasher and bulbs, and it works great. As stated, those newer style flashers work differently, and I think the USA 1156 or 1157 bulbs have more resistance.
 
If you have LED turn-signal bulbs, you'll need a special flasher, for sure. If not...well, it sounds to me like a simple bad connection. If you are using the original socket, it might be time to replace it.
 
Karl - take a look at this post from 2014:

TR2/3/3A - Turn signal flasher stays on?

I installed a new turn signal flasher. The turn signals work fine but the green light continues to blink and the flasher dosn't shut off? Electrical is not my strong point. any ideas on where to look first?
www.britishcarforum.com www.britishcarforum.com

Are you using standard incandescent bulbs? or LED bulbs?
 
I think there must be a short or fault in the wiring because t when I use the switch at the control head the correct turn signal light will flash but that seems to be happening with one of the 3 terminals on the flasher unit not connected at all???? I'm not sure if I have connected the flasher unit wrong or wires are crossed somewhere along the line?
NutmegCT said:
Karl - take a look at this post from 2014:

TR2/3/3A - Turn signal flasher stays on?

I installed a new turn signal flasher. The turn signals work fine but the green light continues to blink and the flasher dosn't shut off? Electrical is not my strong point. any ideas on where to look first?
www.britishcarforum.com www.britishcarforum.com

Are you using standard incandescent bulbs? or LED bulbs?
Click to expand...
LEDs. ...but it turned out to be a bad ground at the green dash light.
 
karls59tr said:
I think there must be a short or fault in the wiring because t when I use the switch at the control head the correct turn signal light will flash but that seems to be happening with one of the 3 terminals on the flasher unit not connected at all???? I'm not sure if I have connected the flasher unit wrong or wires are crossed somewhere along the line?

LEDs. ...but it turned out to be a bad ground at the green dash light.
Click to expand...
We've all been here before.:D:D
 
YET again the aftermarket is a minefield of junk parts. For years there have been a lot of flashers on the market that
simply do NOT work from day one. Lucas is the best bet even if you use an old one.
 
Since this has been solved I will ask a related question. What actually cancels the turn signal when activated? I just finished my restoration and my turn signals do not cancel after a turn. Using regular bulbs. Bruce
 
there should be a cam on the top of the steering column, would have a notch in it to lock to the steering wheel
which flicks the bottom of the stalk to turn them off.
 
This isn't real clear, but maybe it will help. That dark piece is made of spring steel and it clips onto the steering column. It has a cam, indicated by the arrow, which flicks one of two small levers in the turn signal switch when you straighten out the steering wheel.

There is a depression in the spring piece which fits into a hole in the steering column; you can just barely see it in the picture. That prevents the clip from sliding around.

This is from a TR4A. I don't know if it's the same on other cars.
steering.JPG
 
I think I have that piece in one of my boxes. I just got a new steering wheel and I was wondering if this clip can be put in when I remove the original? Bruce
 
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