1966 Town Hardtop Emergency Flasher not working

CuzCrash

CuzCrash

Member
Last seen
Joined
Feb 22, 2019
Thunderbird Year
1966
Hi All,
My 1966 63D 428 town hardtop's Emergency Flashers are not working and never have since I've owned it. That's just over 19 years.
Sequential turn signals and brake lights work just fine, although a little noisy ;O)
I have a new two pin flasher unit and I have two new relays (the ones located in the trunk) on the way.
The two relays in the trunk were burnt out. So I assume that water got into them through the old drain hoses before I replaced the hoses many years ago.
I've checked the overhead console Emergency Warning Flasher Switch/Button and there is power to it and the light (although the light doesn't light up, yet).

My only concern is that when placing a multimeter on either of the connectors that feed the two pin flasher and to ground, both connectors are live 12v. I would have expected that the 383/386 connector ( that goes to X on the flasher) would be live and the 385 connector ( that goes to L on the flasher) would go to ground or be dead until the Emergency Warning Flasher Switch is engaged.

Can anyone help me understand why both these connectors are live please? Even without the two relays connected the flasher connectors are live.

Many thanks in advance.
 

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correction: it's a 1966 63C M code 428. VIN 6Y81Q159546
 
Hi All,
My 1966 63D 428 town hardtop's Emergency Flashers are not working and never have since I've owned it. That's just over 19 years.
Sequential turn signals and brake lights work just fine, although a little noisy ;O)
I have a new two pin flasher unit and I have two new relays (the ones located in the trunk) on the way.
The two relays in the trunk were burnt out. So I assume that water got into them through the old drain hoses before I replaced the hoses many years ago.
I've checked the overhead console Emergency Warning Flasher Switch/Button and there is power to it and the light (although the light doesn't light up, yet).

My only concern is that when placing a multimeter on either of the connectors that feed the two pin flasher and to ground, both connectors are live 12v. I would have expected that the 383/386 connector ( that goes to X on the flasher) would be live and the 385 connector ( that goes to L on the flasher) would go to ground or be dead until the Emergency Warning Flasher Switch is engaged.

Can anyone help me understand why both these connectors are live please? Even without the two relays connected the flasher connectors are live.

Many thanks in advance.
Both flasher pins will read close to 12V (to ground) with the switch "ON". The 386 wire is hardwired to 12V through the 383 wire to the fuse.
The 385 wire will show 12V, with the switch "ON", because it is connected to the 386 wire through the flasher bulb filament. The filament resistance is fairly low, so very little voltage is dropped across it without the flasher in place.

Note that the flasher bulb is wired across the flasher pins. When the flasher is "ON" (contacts closed), the bulb is "OFF". When the flasher contacts open up (due to the bi-metallic strip heating up) the bulb is "ON". Since both emergency relays are still on, the ground path for the indicator bulb is through the 385 wire through both relays to the front/rear bulbs. This bulb does not pass enough current (<270ma) to turn on the eight external 1157 bulbs.

First, make sure both emergency warning relays in the trunk are both grounded securely. The case must be grounded.
Then, verify that you have 12V on the light blue (514) wire at the relay coils.
Next, verify that you have 12V on the white/red (385) wire at the relay inputs.
Finally, verify that there is 12V on their output pins orange (489), white/blue (449), and green/white(448).

Thanks for providing the schematic diagram - it made this post much easier to compose!
 
First of all; my apologies for the confusion of 63C/D M/Q code mix up. My fault entirely.
My big bird is a 1966 Q code 428 Town hardtop with dealer fitted Tripower (3x2bbl).
VIN: 6Y81Q159546
Body: 63C
Color: M
Trim: G7
Date: 05E
D.S.O: 27
Axle: 1
Trans: 4

Thank you soooo much Vic for your most helpful detailed, informative and professional reply. Fantastic!
I have all the new parts now and will install them, following your instructions, next week.
I'll update this thread on results.

Many thanks again and best regards,
Cuz
 
Hi All, I replaced the flasher unit up under the right side of the dash and the two relays in the trunk....and like magic it all works now ! Thank you all for your assistance. Best regards
 

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