Turn Signal Indicator Light Always Flashing

[BT7Doug]

When I purchased by '62 BT7, the turn signals were not working. The problem was in the flasher relay which I replaced from Moss. Thinking I would upgrade to LED lights at some point, I also installed a Moss electronic flasher unit. My BT7 has a three pin device with one pin driving the indicator lamp on the dash. I still have the original incandescent lights installed. My problem is that occasionally after I use the turn signal and then cancel it, the dash indicator light continues to faintly blink. I suspect a possible high resistance short in the turn signal switch. I have no ambition to pull that apart after reading about the fun other forum members have had with that assembly. Has anyone else had this problem and found a fix?

Doug
Gabriola Island, BC

 

[RAC68]

Hi Doug,

The Flasher Relay Box is not a simplistic unit in that its operation is, in some instances, counter to straight forward logic. The attached diagram is one I put together to understand and diagnose issues I was pursuing and believe it could also be of assistance to you as well. Although my BJ8 Phase 1 has the same Flasher box and Flasher as your model, it does have a left and right hand dash indicator. In your instance, the simple way to consider the diagram is as if the left and right Flasher Relay connections are routed to a single dash indicator bulb.

In your review of the diagram, keep in mind that the Flasher "P" terminal provides power to the dash indicator at all times and the Flasher Relay Box provides the ground to the dash indicator for illumination only when a direction is selected. From what I understand, I would check the dash bulb for a clean ground with no interference from any surrounding circuitry or components delivering a phantom ground signal. Since the dash indicator does provide a strong light when the directional is activated and functions appropriately, I see this as a strong indication that your issue is from a false ground.

Good luck,
Ray(64BJ8P1)

 

[Keoke]

Well:


Buy a solid state replecement and get rid of that antique item

 

[vette]

Are you saying that the dash indicator light is flashing and no turnsignal bulb at any corner is not lit at all?

 

[vette]

Doug, I just looked at the schmatic for the early 6 cyl cars and as Ray was stating the dash turn indicator lights gets its power from the "P" terminal of the flasher but the other side gets its ground thru the filaments of JUST THE FRONT TURNSIGNAL BULBS. The Green Red or the Green White wire from the dash light goes to either or the terminals # 2 & 6 of the flasher relay and that is where they are joined with the wires going out to the front turn signal bulbs. The rear turn signal bulbs have no involvement in this scheme. So my thought is to see if terminals 2 & 6 of the flasher relay have any voltage on them when the turnsignals are off. I would lift the Green Red and Green White wires off the terminals before I checked voltage to ensure that there is no backfeed from the P terminal of the flasher. If 2 or 6 have voltage when the turnsignals are off then the trouble is in the relay.
NOW HAVING SAID ALL THIS, I MUST TELL YOU, that I have a BJ7 that has an alternate wiring system from the factory that has only one turnsignal indicator light on the dash. And that bulb on the dash get its power from the "P" terminal of the flasher but the other side of the bulb gets its ground directly from a short black wire connected to a ground terminal on the back side of my cable operated tachometer. And that is exactly how the early 6 cylinder schematics show it should be. So that is a simple circuit with power coming from the flasher and grounding the dash bulb directly to ground. If that is the way yours is wired then the problem is most likely the flasher.

 

[RAC68]

Hi Vette,

As I understand Doug's issue, his turn signals work fine and, when activated, the dash indicator lights. However, the dash indicator continues to flash and glow at a low level even after the turn signals switch off. This would indicate that voltage continues to be present from the Flasher with the bulb activated with a dirty/false ground. It is not the proven grounds provided when the Flasher Relay Box is activated and operating properly that causes the after indicator glow, it is an inadvertent ground that could be caused by a bad bulb or a nearby touching ground wire. I would examine the indicator bulb and wiring near its installation that may be touching the socket.

Ray(64BJ8P1)

 

[BT7Doug]

Thanks for all the input to help me fix this problem. The flasher and flasher relay are solid state and therefore need a lot less voltage to activate. My BT7 does have a dedicated wire from the flasher (3 pins) to the indicator lamp on the dash. The flasher is connected between the fuse box and the flasher relay. If a ground is made through the relay, the flasher will switch the voltage to the relay and power the indicator lamp on the dash. The direction switch (trafficator) provides the connection to the ground through the correct signal lights. Somewhere there is a phantom ground that is activating the flasher but not powering the lights. The flasher relay is mostly hidden below the fresh air duct which makes taking measurements more challenging but I will give it another shot.

 

[RAC68]

Doug,

As I understand your issue, I believe your Flasher Relay is functioning properly based upon your initial indication of functional signal operational correctness when properly activated through the trafficator. However, your issue of a continuing low glow from your dash indicator indicates that a false low-level ground is being supplied to the lamp socket that is activating the bulb. Have you checked to see if the lamp socket has a common/ground connection (even if not substantial) when the electrical system is off with the battery switch turned off. I would also check and record if a common connection exists when the system is properly activated as well as after the trafficator is turned off. If you still have even a low level common connection after signal deactivation, I would then check to see if the line from the Flasher Relay Box is still providing a common connection....if not, then it is a common from nearby (socket) interference.

Since your signals operates properly when activated, I don't believe this is a voltage issue. Since I have had issues with faulty bulbs and flashers, as a last attempt, I would first replace the indicator bulb and then try a different flasher (possibly borrowed from a friend) although I presently have no reason to believe it is your flasher.

Good luck,
Ray(64BJ8P1)

 

[vette]

Doug, From your discription here I don't think you are looking at the circuit correctly. I will try to state my points. I appologize if I am misinterpreting what you are saying.

. My BT7 does have a dedicated wire from the flasher (3 pins) to the indicator lamp on the dash.
They all do. the "P" pin of the flasher should go to the dash bulb. If it is one dash indicator bulb this wire should be either light green or light yellow. If there is one dash indicator bulb my point is that the other side of the bulb will be connected directly to a ground screw at the back of the tach. It will not go over to the turnsignal relay.

The flasher is connected between the fuse box and the flasher relay. I don't understand your statement here. Yes the flasher gets its power either directly from the fuse box or it gets it from the ignition switch depending on the year of the car. It gets its power coming in on terminal "B". Then the flasher sends "flashing" power out on terminal "L" to #1 terminal on the Turnsignal Relay, that should be a green/brown wire. When the flasher flashes effectively sending its flashing power to the #1 terminal on the turnsignal relay it also sends flashing power from the flashers "P" terminal to the dash indicator bulb. If this is a single bulb arrangement which some Healeys have this single bulb is grounded by a short wire to a ground screw on the back of the tach and then the bulb will flash as the turnsignals flash. If the Healey has two indicator bulbs on the dash then these bulbs respectively have there ground side connected to either the number 2 or the number 6 terminal of the turnsignal relay this is only in order to get them connected to the wire that is going to one of the front turnsignal bulbs which ever side is intended to flash.

If a ground is made through the relay, the flasher will switch the voltage to the relay and power the indicator lamp on the dash.
Maybe I can interpret your statement to mean this: When the turnsignal relay is energized to turn on the one side of the turn signals or the other, the turnsignal then connects the terminals #2, #6, #3, & #7 to their respective turnsignal bulbs and this causes the flashing power coming into the Relay on terminal #1 to be sent to its respective bulb. When the flasher is causing the outside bulbs to flash it is also causing the dash indicator to flash because the dash indicator bulb is connected to the "P" terminal of the flasher. Possibly I can interpret your statement about a ground is made through the relay as meaning that when the relay connect one of those previously stated terminals to the outside bulbs that allows the dash indicator bulbs to get grounded by a path that is going out to the filaments of the outside bulbs. BUT THIS ONLY APPLYS IF THERE ARE TWO INDICATOR BULBS ON THE DASH. IF THERE IS ONLY ONE INDICATOR BULB ON THE DASH THIS SCHEME DOES NOT APPLY. If only one indicator bulb on the dash it has a ground wire connected to the back the tach and the turnsignal relay is not relevent.

The direction switch (trafficator) provides the connection to the ground through the correct signal lights.
The trafficator energizes the turnsignal relay by energizing either terminal #4 or #8 which ever side is chosen. This then closes in the relay making terminal #1 which is the "flashing power" from the flasher gets itself connected to the respective outside bulbs. So when you say the trafficator provides a connection to ground, that's not terminology that I understand. The trafficator energized the turnsignal relay which in turn energizes the turnsignal bulbs. And yes that ultimately does provide a ground path for the dash indicator bulb. BUT AGAIN I HAVE TO SAY, "ONLY IF THERE ARE TWO INDICATOR BULBS IN THE DASH" If there is one bulb this bulb is not connected to the turnsignal relay.
Somewhere there is a phantom ground that is activating the flasher but not powering the lights. The flasher relay is mostly hidden below the fresh air duct which makes taking measurements more challenging but I will give it another shot.

I have included pictures of the relay and the flasher so as to be able to review the connections and what they are connected to. I appologize if I have totally misinterpreted your statements.

 

[RAC68]

Hi Doug/Vette,

I stand corrected in that the ground is different for a single dash indicator as with those having 2 dash indicators. Based upon Vette's explanation, I can appreciate his analysis but contend the flasher is still providing a low level of power to the dash indicator even when none should be transmitted. Since a ground is permanently fixed to the socket, flasher supplied low level power seems to be causing your glowing dash indicator light. As stated before, I would look and test the ground connection at the socket, then change the bulb, and finally borrow a flasher for testing. I still do not believe it is your Flasher Relay Box but I now see why Vette suggest testing.

Sorry for any misleading interpretation I may have extended and not being more understanding of Vette's evaluation.

Good luck,
Ray(64BJ8P1)

 

[vette]

Doug, my point in all this is that if you have one dash indicator light instead 2 then I believe the fault is in the flasher because the relay should not be involved. But then another scenario could be that the contacts in the relay are not opening completely. That's whey I originally said to take a close look at the turnsignal bulbs at each corner to make sure they are not on at all even dimly. If not barring that you might have done something different with the wiring then I believe it very well could be the flasher. Good Luck.
Ray I just now see your recent post, I too think it is the flasher, but current flowing thru the malfunctioning relay could be causing the flasher to close the pilot light contact a wee bit. Always good to hear from you. or I might say that it is keeping the flasher from releasing the pilot light completely. But yes I would change the flasher first.