New strange electrical problem

Leo2+2 · Guru

New strange electrical problem

pontiax · Poncho Master!

I had a similar problem years ago with a 62 chevy. Found it to be a fault horn relay(junction block).
Corroded terminals on the block caused intermittent problems with different circuits .This might give you a place to start.

Leo2+2 · Guru

And what did you do? Did you disconnect each cable and sand the terminals or something like that?

Thanks for your input,

Leo

Mike Ward MB · Addicted!

Sounds to me like you've blown a fuse. Dash lights and tail lights are common to a 3a fuse. The fun part is finding what caused the fuse to blow.

Same thing happened to me in my 66 Beaumont. The horn is on a separate feed (I think) so I don't get the correlation there but a DC ground can get some strange things happening.

cdnpont · Canadian Poncho Superstar!

Absolutely check all the fuses. Blown fuses do weird things. I had a brake lamp fuse go, and it took out the running and dash lamps. I understand maybe the alerting aspect to take out the dash lights, but running? Go figure.

hawkeye5766 · Canadian Poncho Superstar!

Leo2+2 wrote:

- if I put on the hazard lights then everything blinks including the lights in the dash.

Leo, do you mean the dash turn indicators blink or the dash lights themselves? If the dash lights are blinking then you have a short.

Leo2+2 · Guru

hawkeye5766 wrote:
Leo2+2 wrote:

- if I put on the hazard lights then everything blinks including the lights in the dash.

Leo, do you mean the dash turn indicators blink or the dash lights themselves? If the dash lights are blinking then you have a short.

I will re-describe properly: with the parking or headlights on, no dash lights but when I put on the hazard lights the dash lights blink lightly and if at the same time I hit the brake pedal, then the dash lights blink but in full intensity. They blink at the same rate as the flash indicators which actually work properly all the time. As a reminder this happened when I tried to honk.

MC · Canadian Poncho Superstar!

I'm definitely not an electrical expert, but I have had strange things happen because of a bad ground or a short. Seems that if you take a ground out or put a short in, it can change the way a circuit works so stuff goes out when it should come on or comes on when it should go out. Or sometimes shorts out after surpassing a certain load.

If you have wiring diagrams check and see what is on that circuit and maybe start there. Check fuses to see if one is blown that might be connected to that circuit somewhere.

Do your brake lights come on when you hit the pedal?

hawkeye5766 · Canadian Poncho Superstar!

So..your dash lights do not come on at all with parking lights turned on but they blink off and on when your hazards are on(right?) If thats the case sounds like a short. Did you not put a new steering column in not too long ago? As stated check fuses first, then I'd unplug the column harness and see if dash lights work properly...this will help narrow it down.

-- Edited by hawkeye5766 on Saturday 18th of November 2017 12:47:26 AM

hawkeye5766 · Canadian Poncho Superstar!

Your brake lights are fed through you turn signal switch,one just cancels the other. So with your turn switch down(left turn) it shuts off the brake light and engages the turn flasher. Up (right turn) does the same thing and neutral(middle) sends power to both rear lights for the brakes. If your dash lights get brighter when you also apply the brakes it's because the current has increased to the rear of the car causing more current to the dash lights in the case of a short.

4SPEED427 · A Poncho Legend!

One thing you could try is unplug the harness that runs under the driver's seat to the back. It feeds tail lights, brake lights, back up lights. At least that would tell you if the problem is in the front or the back.

JC2+2 · Poncho Master!

Sounds like ground issue to me. If a signal light is lacking ground it will back feed through the bulb to the parks to complete the circuit. I'm sure everyone has seen an old holiday trailer or motor home with the clearance lights flashing with the signals. Those things have the worst grounds.

rabbit64cs · Canadian Poncho Superstar!

Bad grounds, and re do the connections on the horn relay , as mentioned .

pull your fuses , clean them with a scotch brite, scrap the terminal holders.

I've had similar problems with my old girls.. Usually just time to find poor connection, bad grounds do crazy things .

Greaser · Canadian Poncho Superstar!

I had a similar no dash light problem in my 63, solved by taking out the light switch out,dismantled it,

cleaned all the terminals and corrosion from inside the switch.

Replaced the blown fuse and all the lights were back to normal.

Leo2+2 · Guru

I'm going to try out several things as per all the ideas mentioned and will post again regarding the results.

Thanks all.

JC2+2 · Poncho Master!

hawkeye5766 wrote:
JC2+2 wrote:
Sounds like ground issue to me. If a signal light is lacking ground it will back feed through the bulb to the parks to complete the circuit. I'm sure everyone has seen an old holiday trailer or motor home with the clearance lights flashing with the signals. Those things have the worst grounds.
Was thinking that too...but the dash lights aren't on the same circuit as brake/turn...should be no connection between the two and he states the dash lights were getting brighter..not dimmer? Poor ground draws from one system to support another. So when you hit the brakes and you parking lights dim it's the resistance(power draw) trying to get to ground which causes voltage drop. So with more load(turn and then brake) the dash lights should dim? Just guessing at this point,hard to tell when your not there.

-- Edited by hawkeye5766 on Saturday 18th of November 2017 03:31:02 AM

Dash lights and turn indicator lights would still share the same ground in the dash cluster. Pull out the dash light fuse and see what happens. But rereading your first post, you say no dash, tail or park lights. Recheck your fuses and use a test light to check for power on both sides of fuse. If you've lost power in the fuse box for the lights, check the main harness connector through the firewall. These cars have problems there with poor connection. Wiggle the harness there and see what happens.

hawkeye5766 · Canadian Poncho Superstar!

JC2+2 wrote:
hawkeye5766 wrote:
JC2+2 wrote:
Sounds like ground issue to me. If a signal light is lacking ground it will back feed through the bulb to the parks to complete the circuit. I'm sure everyone has seen an old holiday trailer or motor home with the clearance lights flashing with the signals. Those things have the worst grounds.
Was thinking that too...but the dash lights aren't on the same circuit as brake/turn...should be no connection between the two and he states the dash lights were getting brighter..not dimmer? Poor ground draws from one system to support another. So when you hit the brakes and you parking lights dim it's the resistance(power draw) trying to get to ground which causes voltage drop. So with more load(turn and then brake) the dash lights should dim? Just guessing at this point,hard to tell when your not there.

-- Edited by hawkeye5766 on Saturday 18th of November 2017 03:31:02 AM
Dash lights and turn indicator lights would still share the same ground in the dash cluster. Pull out the dash light fuse and see what happens. But rereading your first post, you say no dash, tail or park lights. Recheck your fuses and use a test light to check for power on both sides of fuse. If you've lost power in the fuse box for the lights, check the main harness connector through the firewall. These cars have problems there with poor connection. Wiggle the harness there and see what happens.

Was late, have too agree. Was thinking dash lights were shut off when this was happening.

Leo2+2 · Guru

Tail light 20A fuse was burnt. Replaced it and issue resolved.

Now ... horn doesn't work! Next project for tomorrow.

4SPEED427 · A Poncho Legend!

It's amazing how often something that seems so baffling, so complicated turns out to be a simple fix. Glad you found it.

The horn by itself should be an easy one!

JC2+2 · Poncho Master!

Do the dash lights flicker with the signals or hazards on? You may still have a ground issue there. A burnt tail light fuse won't cause dash lights to come on with signals or hazards.

DonSSDD · Canadian Poncho Superstar!

Once your car is working working right electrically, I think on a 67 and years around then when 4 way flashers became standard eqpt, you can listen to the radio with no key. Turn radio on, turn 4 ways on, turn left signal on, radio should work. It will go on and off with the flashers sequence, put foot on brake and the flashers and the radio will stay on. With a modern electronic flasher, not sure if foot on brake stops the flashers flashing.

This must work due to some very interesting wiring from factory?

Leo2+2 · Guru

JC2+2 wrote:
Do the dash lights flicker with the signals or hazards on? You may still have a ground issue there. A burnt tail light fuse won't cause dash lights to come on with signals or hazards.

John, all OK now and working normal. Thanks.

Leo2+2 · Guru

DonSSDD wrote:
Once your car is working working right electrically, I think on a 67 and years around then when 4 way flashers became standard eqpt, you can listen to the radio with no key. Turn radio on, turn 4 ways on, turn left signal on, radio should work. It will go on and off with the flashers sequence, put foot on brake and the flashers and the radio will stay on. With a modern electronic flasher, not sure if foot on brake stops the flashers flashing.

This must work due to some very interesting wiring from factory?

I tried this but nothing happens, maybe another member can try it on his car and see what results they get. Key on accessory is bare minimum to get the radio working. However the convertible top doesn't need the key in the ignition to work.

When 4-ways are on and you put the foot on the brake the flashers stay on. I remember this on my dad's cars well into the 80s as well.

Cheers

Mike Ward MB · Addicted!

Leo2+2 wrote:
Tail light 20A fuse was burnt. Replaced it and issue resolved.
Now ... horn doesn't work! Next project for tomorrow.

A 20a fuse is a bit high for the tail light/dash light circuit. Coincidentally you'll find a 20a on my circuit which I put in there after after blowing a package or two of the correct amperage while troubleshooting. Nothing smoking yet but I didn't really find the problem. That 20a in yours may very well be there for the same reason.

DonSSDD · Canadian Poncho Superstar!

Leo2+2 wrote:
DonSSDD wrote:
Once your car is working working right electrically, I think on a 67 and years around then when 4 way flashers became standard eqpt, you can listen to the radio with no key. Turn radio on, turn 4 ways on, turn left signal on, radio should work. It will go on and off with the flashers sequence, put foot on brake and the flashers and the radio will stay on. With a modern electronic flasher, not sure if foot on brake stops the flashers flashing.

This must work due to some very interesting wiring from factory?
I tried this but nothing happens, maybe another member can try it on his car and see what results they get. Key on accessory is bare minimum to get the radio working. However the convertible top doesn't need the key in the ignition to work.
When 4-ways are on and you put the foot on the brake the flashers stay on. I remember this on my dad's cars well into the 80s as well.

Cheers

It could be you have a newer electronic flasher. The first years for standard 4 way flashers was around 67, it worked for the first year or 2, then not after that. Original 4 way flashers stopped flashing when you had your foot on the brake.