Question on flasher of BN6

[RAC68]

Gary, you may be correct and I will stand corrected but I don’t think so. As far as I understand, the external signal lights are grounded through the sockets but NOT the dash lights. The dash lights are grounded through the “P” contact of the flasher.

Ray (64BJ8P1)

 

[GregW]

From mgaguru

From the Healey shop manual

 

[RAC68]

Hi Gary,

Thank you and I will stand corrected but I just don’t see where I am going wrong.



I can understand that the flasher described in the manual would work in a Healey having a single dash indicator with a ground attached to the dash bulb. However, I am not sure this flasher would work in a BJ8 with 2 directional dash indicators. As the wiring diagram seems to indicate, power flows from the “L” terminal as described in the manual unit, to the directional switch and directly on to the selected 2 signal lights and correct side dash indicator. If the connection is as described in the wiring diagram, both dash indicators are routed to the "P" terminal of the flasher. So, either the dash indicator bulbs are grounded and are not connected to the "P terminal or the "P" terminal serves to connect the dash indicators to a ground and the ground is connected to the flasher and not internally wired as described in the manual.

Gary, I would really appreciate your direction in where am I going wrong?

All the best,
Ray (64BJ8P1)

 

[GregW]

Hi Gary,
I just don’t see where I am going wrong.

It's Greg

I can understand that the flasher described in the manual would work in a Healey having a single dash indicator with a ground attached to the dash bulb. However, I am not sure this flasher would work in a BJ8 with 2 directional dash indicators.

It works the same except with the duel dash indicators, there is an extra wire. The green/red wire and the green/white wire are connected to ground though the filament of the bulb. This is done so if a bulb burns out, the ground is broken and there isn't enough load to heat the filament in the flasher. That warns the driver that something is amiss. What threw me for the longest time is the light green/purple wire going to both dash lights. It was wired as common which has always meant ground to me. That's about the extent of my understanding of the circuit.

 

[GregW]

Sorry for the side bar Volker,

Gents, I am still in analysis phase ;-) Checked the permanent electric current which is connected to the direction swith. When the flasher is not turned on I have stable 12.09 Volt. As soon as I turn the flasher on the electric current starts to be dynamic between 11.90 and 12.00 Volt

That variation is probably the contacts in the flasher unit making and breaking contact.

Next update: When the ignition switch is turned off I have 12.43 Volt at the Brown with Blue in wire and 0 Volt at the 2 white out wires. When I turn the ignition switch the electric current at the in wire is still 12.43 Volt, at the out wires I have only 11.50 Volt. Hence I "loose" electric current in that scenario.

That drop in voltage is just things in the system drawing power. The ignition coil and the ignition warning light to name two. Shouldn't be a worry.

What I am wondering is that at the White with Black wire from the ignition coil to the distributor I measure 0.18 Volt when the ignition switch is turned on. The engine is not running in that case and the starter button not pressed, of course. Is this expected?

I've never bothered to read that wire, so I don't know. That wire disables the ignition by the battery switch in the trunk(boot). Maybe the contact on the switch is a little dirty, they have caused problems for people from time to time.


Try this test from the manual just to be sure. Most likely you'll be doing what Tim said at the beginning of this thread.

 

[BN6_2197]

Greg, started the ckeck:
* 12.15 V at battery
* 10.42 at connector L and B of the flasher unit.


Can I really bring L and B directly in contact?

 

[TimK]

Greg, started the ckeck:
* 12.15 V at battery
* 10.42 at connector L and B of the flasher unit.


Can I really bring L and B directly in contact?

Yes, it bypasses the flasher unit and sends current directly to the bulbs. They won't flash, however. The will stay on as long as the ignition and directional lever are on (left or right).

 

[GregW]

What Tim said. However I'd pull the light green wire off the flasher and combine it with the green/brown wire. This will bypass the flasher contact for the dash and put the dash light on the same circuit as the exterior lights. If the dash light starts blinking normally, you know that the flasher isn't working partially.

 

[TimK]

What Tim said. However I'd pull the light green wire off the flasher and combine it with the green/brown wire. This will bypass the flasher contact for the dash and put the dash light on the same circuit as the exterior lights. If the dash light starts blinking normally, you know that the flasher isn't working partially.

Great idea, Greg!