Electrical issue with the indicators

[HemiCudaAus]

Hi everyone, greeting from Australia.

Just quick question, when I drive my 1970 cuda at night with the headlight ( or even the running lights on ) when I indicate left or right or even hit the brakes, the dash lights dim.

So in saying this when I hit the brakes and the dash lights dim.

When I hit the indicators either left or right the dash lights blink on and off ( but not fully off ).

Grounding issue???

Any ideas would be greatly appreciated.

Thank you

 

[pschlosser]

Some dimming at idle is kind of normal, because the alternator is outputting less current at idle. These alternators have several (maybe 6?) diodes in them, and over time, they begin to fail one at a time, and the alternator can output less, and less current until that last one goes, then it's totally kaput.

There are indeed grounding issue that can arise regarding the front instrument illumination, but if you were having that issue, the dimming or poor output would be more or less constant.

I, too, have seen illumination vary at a stop light, at night with headlights on (those suckers draw a lot of current), where the engine is idling, so alternator output is low. The instrument illumination (light bar) may pulse as the turn signal indicators go on and off. and if I put it in neutral, and rev the engine up a little, I see the dash illumination get brighter.

to improve, look at the alternator and/or voltage regulator. switching to lower current draw head lamps, such as newer LED types, can help, too. the more juice in the system, and the less being used up, when at idle, mind you, the better.

 

[HemiCudaAus]

Some dimming at idle is kind of normal, because the alternator is outputting less current at idle. These alternators have several (maybe 6?) diodes in them, and over time, they begin to fail one at a time, and the alternator can output less, and less current until that last one goes, then it's totally kaput.

There are indeed grounding issue that can arise regarding the front instrument illumination, but if you were having that issue, the dimming or poor output would be more or less constant.

I, too, have seen illumination vary at a stop light, at night with headlights on (those suckers draw a lot of current), where the engine is idling, so alternator output is low. The instrument illumination (light bar) may pulse as the turn signal indicators go on and off. and if I put it in neutral, and rev the engine up a little, I see the dash illumination get brighter.

to improve, look at the alternator and/or voltage regulator. switching to lower current draw head lamps, such as newer LED types, can help, too. the more juice in the system, and the less being used up, when at idle, mind you, the better.

Thank you!!

I actually did not think of that.

I will take the car put tonight for a cruise ( summer here in Aus ) and will give it a rev up and turn on indicators and see what happens.

If it is the case, i will be heading straight to an Automotive shop and purchasing low draw LED Globes and see what happens from there.

I will keep you posted.

 

[Chryco Psycho]

Make sure your grounds are good

 

[HemiCudaAus]

Make sure your grounds are good

Those would be the ones under the dash I would presume?

 

[Challenger RTA]

Above is good information. Also check the bulkhead connections. 16 and 18. Bad connections reduce voltage there. Alternator not feeding the load to splice one and not bringing the battery up to full state of charge.

I myself would check voltage at the battery and at the alternator stud. That is with engine running and off.


Follow the dots. Understand how it's wired first. Blue charge circuit, yellow battery supply, red ACC circuit. Headlight sw is feed from splice one under dash.
One word explains the wiring and connections. Inadequate! Read Description and follow the dots. The wiring is not heavy enough and the connection were not designed to carry that much amperage 1:RED wire 16 Battery power yellow dot to splice one feeds fuse block, 2:charge wire 18 black wire blue dots to splice one through amp meter to red wire blue dot 16 to battery, 3:ACC feed from splice 1 Red wire Q3_12R yellow dot to steering column. Black wire 12BK red dot to ACC side of fuse box.ch load. The round back alt has an output of 37 to 45 amps max and the wiring is designed for that.
When everything is in good shape.

Also check the foot dimmer switch. It might be shorting out.

 

[Chryco Psycho]

more at the lights , if the housings are not grounded properly with clean surfaces it will try to ground through other circuits

 

[Challenger RTA]

more at the lights , if the housings are not grounded properly with clean surfaces it will try to ground through other circuits

Thread 'Dash lights a Brighter possibility'

May 24, 2024

Dash lights a Brighter possibility. Took gauge cluster out to clean all connections. Found some light sockets rusted. Cleaned all cluster and switch terminals and grease. Had the dimmer switch out and jumped with a wire while working on it. I think I still have a problem with the socket for the clock. I'll take it out and check it. The bulbs I used are listed above each picture. As Huskydrive said they dimmed have yet to try that. I'm sure they do.
@Huskidrive posted what he used for dash lights. I tried and like it. I give him credit for this...

• Challenger RTA
• Replies: 5
• Forum: Electrical and Ignition

As far as grounds for the dash. it is established through the dash mounting bolts on the A pillars and the defroster area bolts. The the light bar is ground through the mounting screws. Then light socket are grounded where they are inserted into the light bar.

 

[70cudanut]

Hi everyone, greeting from Australia.

Just quick question, when I drive my 1970 cuda at night with the headlight ( or even the running lights on ) when I indicate left or right or even hit the brakes, the dash lights dim.

So in saying this when I hit the brakes and the dash lights dim.

When I hit the indicators either left or right the dash lights blink on and off ( but not fully off ).

Grounding issue???

Any ideas would be greatly appreciated.

Thank you

90% of the time it’s a bad ground somewhere

 

[HemiCudaAus]

Hi everyone,

So, at this point, I just drove home with the car for approximately 40 miles at speed for most of the time ( 60 miles per hour ).

When I was driving home I did notice on the trip home that the Amp Gauge was continually in the discharge position.

When I arrived at home, I went to start the car, and it was very difficult to start.

I checked the voltage at the back of the alternator and it was reading 11 volts.

I conducted the good old idle test and disconected the ground on the battery whilst the car was idling and it cut out immediately.

I have ordered a new factory alternator and hope that this resolves the problem.

I will keep you all posted.

 

[Challenger RTA]

Charging circuit. I would say for the most part you know what your doing. Below might be help.

 

[Challenger RTA]

This is for stock Mopar charging system.

1:With the key in the off position should have on the alternator output battery voltage.

2:The field wires should both read zero we should have no voltage.

3: If there is voltage at the field wires with the key off, there is a wiring problem.

4: If no voltage at the alternator output stud with the key off then we likely have either a dead battery or we have a wiring problem or blown fusible link.

5: With the key in the on position. there will be voltage at the alternator output, it's going to be lower than what it was with the key off, because the entire vehicle is energized. The voltage drop is going to be more you can still see it go from
12 and a half down to 11.7. Still going to have near battery voltage.

6: What's important. With the key on. The field wires should have voltage. It won't be full battery voltage but it's has power coming to the alternator and it will be a lot less on one side and one side is high. That's the inlet so that's power going into the field windings.
The other one, the one that's low is the output from the field windings.
The output from the field winding is what goes back to the voltage regulator.
The voltage regulator on this is simply a switch ( Remember it needs a good ground to function.) all it's going to do is connect this field terminal here to ground and when it connects it to ground electricity then flows through the field windings energizing it and causing the alternator to charge.

7: Run test: This is for stock Mopar charging system.
Before doing the run test you're going to want to connect directly to the field output terminal on the alternator with some sort of a jumper wire. You can remove the existing field wire if it helps you to get to it. Use a jumper wire that comes back to the battery and it's not connected to anything right now. Have the voltage meter connected to the battery. Just checking battery voltage 12.3 volts there abouts. By touching the jumper wire to the negative terminal.
Just grounding it you can hear the engine load up because it's pulling a load and the voltage runs up to 14. That tells you that when the field in the alternator is energized it's charging. The alternator is good. Now you know that it's not an alternator problem at this point. If it's not charging you have a no charge scenario but this passes then you know it's the voltage regulator or some wire to it. It's most likely the voltage regulator and that's all it takes to diagnose the charging system on one of these
Here again If the any ground is bad or loose. it won't charge correctly or reliability. They become phantom grounds that just keep haunting you! That being the Voltage regulator ground, chassis ground, engine ground, Bolts, bolt holes, nuts and mounting brackets. 99% of the time there overlooked. The whole car is a ground.