The Dodge Challenger Message Board

cv70chall wrote:My headlight on/off switch that controls the parking lights and headlights is fine (unless there is something I am missing)
I had hoped the relays would have solved my issues though.

Relays will stop a good switch going bad. But it that on/off switch is the original one it probably has already gone bad which is what we suspect would cause your issue. The dimmer switch only effects the dash lighting.

The foot switch might be at fault but they are more robust. Usually it is the fault of the off/on switch. If it is the dash as well as the headlights flickering then it is the off/on switch for sure.

cv70chall wrote:As far as the regulator, I am going to make sure it's completely grounded and then run another test- engine running at idle- meter on battery.
(I was always told your voltage range was supposed to be 13.9v to 14.5v nominal and no higher than 14.80v-15.0v at increased RPM's.

Not true huh?

I didn't say that. You said in your post that you thought 14.5 was on the high side? Or did I read it wrong?

With a regular lead/acid battery 14.5 volts is the ideal. From 15 volts - up it will start to "boil" the acid.

So, let me make sure I have this correct.
I was getting 14.5 to 14.76 volts on my meter off the battery- engine running. At increased RPM's, voltage increased to 15.2 to 15.65 volts, which I suspected as high.
So, that would lead me to believe the VR was bad. (I don't want to ruin a new battery)

As for what you said about the headlight ON/OFF switch which is located on the left dash panel just above the dimmer- can a bad switch still actually work? Reason I am asking is, it seems to work normally.
I'm asking because I want to be sure and if I need to replace all the original switches while I have that dash panel out, so be it.
(Your idea of the On/OFF switch being bad could make sense- seeing as the lights still flickered with the dimmer switch removed)
If I can remove this switch and clean the contacts, would that suffice or should I just replace it if you still think its bad?

Thanks Dave-

If you are having trouble with the headlights, check that your (foot-operated) high-beam switch connector is firmly inserted into the harness.
I had a problem a couple years ago (headlights flickering, then they died and the instrument cluster lights died too, in the middle of the night of course). I flicked the road lights on and drove the rest of the way, made it to my destination and fiddled on the (dark) parking lot for half an hour with the headlight switch, dimmer switch, still didn't work.
I lifted the carpet to check if the harness was damaged (it was a brand new repro, barely installed), and it wasn't, but it seemed a bit short, taut, and the connector was barely on the footswitch. I pushed it in again firmly, and all the lights went back on.
Though about it later, and came to a conclusion : that switch is an inverter wired in series between the headlight switch and the lights. One wire goes in (headlight power), two come out (low beam/high beam).
No switch == no lights. Still don't understand why the cluster went out too.

cv70chall wrote:So, let me make sure I have this correct.
I was getting 14.5 to 14.76 volts on my meter off the battery- engine running. At increased RPM's, voltage increased to 15.2 to 15.65 volts, which I suspected as high.
So, that would lead me to believe the VR was bad. (I don't want to ruin a new battery)

It's not bad if it is grounded to the body correctly. Don't just guess. MEASURE IT with a meter.

If I can remove this switch and clean the contacts, would that suffice or should I just replace it if you still think its bad?

Thanks Dave-

I only replace things when they are faulty. I don't just guess they MIGHT be faulty. It MIGHT be the headlight switch. It MIGHT be the foot switch. It MIGHT be a bad connection on the bulkhead connector. I don't know. But I would find out which it is before replacing anything. You do that with testing.

I totally agree.
When we were reassembling this car, I took it upon my self to clean ALL electrical contacts, plugs, harnesses and connectors. Sanded contacts to remove any corrosion, gunk and grime. (Even took some to the grinder wheel when they fought me!)
I ran the 10g "upgrade ampmeter bypass) through the bulkhead connector and made sure that was clean and secure. I thought I had covered all the bases.
Funny thing is- the lights were not always doing this. This started about 6 months ago, so it's either a swtich that's gone bad...or the ground at the VR is weak. I plan on checking this over the weekend.
Pesky crap!

The electronic voltage regulator has an output operating range of 13.3 to 15.9 volts dependant on temperature.
Unsurprisingly the results are lower as ambient temp increases, but it shows how high the output can safely be.
Try getting yourself a basic Chilton repair manual Chuck, covers all these systems in accurate and minute detail.
Like Daveman says, you have to do the tests, speculating on electronic component condition is only expensive and frustrating

Hello everyone and happy holidays! I wanted to "vent" some more about my ongoing issues with my flickering lights- which are still an issue.
I installed the headlight relays (one for lo and one for hi beam).
I then decided to replace the HI-LO Beam Floor Switch- cleaned and made sure it was well grounded.
I replaced BOTH the Headlight switch AND dimmer switch in the dash panel.
I then removed the Voltage Regulator, made sure BOTH screw areas were scraped to bare metal so there would be an excellent ground.
I then bolted the top screw so the VR is VERY secure to the firewall.
I then checked the bulkhead connectors- removing and re-seating all of them.

And still I have flickering lights. @^&*#$#!!!!

I then decided to meter everything and got the following:

At Battery- IDLE 13.6- 14.0 volts REV UP 14.75- 15.5 Volts
Then, I decided to check at the alternator- and was only getting 5.7-6.5 volts. ?????
This was with probes on positive and negative posts of alternator.
Is this right or was I not placing probes in the right spots?
If correct, could this whole issue be a bad alternator and if so, how do I explain the increased voltage at higher RPM's?
This could partially explain the fact that when revved- the lights do not dim.

????

It's the side/headlight switch in the dash Chuck, I'm sure of it

On the increased voltage at the battery on a fast idle, yes, you're making the alternator spin much faster and the max vdc at the regulator is about 15 vdc so what's the surprise there?

There isn't a ground or negative terminal on the alternator, well there is a ground cos its the casing, that's why you can't get a reading at the terminals, one is an output back to battery, the other one or two are field terminals that go back to the regulator. Do you have an electronic reg? Or a dual field alternator?
Put a positive test lead on the output wire and the other on the alt case or the neg batt terminal and try reading it again.

And Happy New Year to you to mate, hope you had a blast over the holidays

Hi Adrian and Happy New Year to you, too sir!

As I said, I replaced EVERY switch. BOTH the headlight switch and dimmer switch in the dash (left side panel) next to the wiper switch AND the floor HI LO beam switch.

No luck...
What now?

As for the alternator, it's an original style standard Mopar alternator and I will try one lead on the positive terminal and ground the other to either the chassis or the frame to get a good reading.

If you have an early (mech) type regulator you must use it with a single field alternator, but if you have a dual field alternator then you should have an electronic regulator.

Sorry I must have misread somewhere, I didn't see a post where you replaced the light/headlight switch in the dash.

While you're on this run a 12 gauge bypass wire from the alternator output terminal straight to the positive battery post. That will help take load off the connector block where there is certainly some resistance.

Adrian-

I have the electronic voltage regulator (see pic) and OEM style alternator.
Do I need to run that 12g wire as a permanent run?

Yep that bypass was used on high output alt from the factory.
It saves a lot of amps going thru a shit conn block and the dash.

If you have an electronic regulator the alternator must have two field terminals, easy to spot.
Just tryin to figure if your system has the right components in an attempt to diagnose your problem.

Ok, so you are saying I SHOULD run that 12G wire from the alternator positive terminal to the battery, right?
I will snap a few pics of it and send them to you over the weekend.

Thanks Adrian!

Read this Chuck, explains it better than I ever could ..........everythings in there, bypass upgrades, alternator and regulator upgrades etc

http://www.allpar.com/history/mopar/electrical.html

Adrian Worman wrote:http://www.allpar.com/history/mopar/electrical.html

And also the following page, on the same website Dave gave the link to last year for the dim headlights problem :
MAD Electrical Amp Gauge Bypass

The simplest way to accomplish this is to install a large gauge wire (see below for sizing) between the alternator output and the battery stud on the starter relay (including a suitably sized fusible link, 12 gauge link for an 8 gauge wire).

The wire current capacity should be just a bit above the maximum alternator output current.
For example, if you draw the wire back from the alternator along the engine harness, behind the brake booster, and forward to the starter relay, you'll probably end up with a 5 or 6-foot wire.

Wire capacities in current vs length can be found for example here

Suppose you have a 37 amp alternator (the standard size in most Mopar Applications in 1970), a 10 gauge wire is OK for that current and that length. A 14 gauge fuse link is OK to protect a 10 gauge wire. Have a spare fuselink in the glove box.