73 Charger electrical gremlins

[Matt73Charger]

Firstly hi to everyone. Hoping that this forum will provide useful info and tips for my restoration.

So, just purchased a 73 Charger here in the UK. Its a 400 Rallye and came from California. It's in OK condition, as in its usable as it is and mechanically it seems all good, but the paint wants redoing and all the electrics, so I plan on doing a full restoration to it.

As with a car this old, its had various things added/removed over the years electrically, so the fun part is removing stuff that has been added and sorting any faults.

First thing noticed is the headlights, whilst driving it home after buying it, they were working fine but then decided to start turning off and on, which isn't helpful at night  
I'm thinking possibly the headlight switch? (how is it removed?) but also, when the indicators are switched on, all the lights (headlights, dome light, dash lights etc) all dim and brighten in response to the indicator. A bad earth somewhere possibly? the indicators also work sometimes but sometimes don't. I can see its had a new relay fitted but I'm thinking it could possibly be the switch on the column?

Obviously I will renew all the wiring once all the paintwork has been done, but I'd like to get things at least working before then.

I've worked on cars professionally for 20+ years but this is my first US motor, so I'm trying to learn new things with these, so excuse any stupid questions, of which im sure there will be plenty   and requests for parts, as various parts are missing or want replacing.

Oh and im awaiting delivery of the workshop manuals, which seemed like a must as a first purchase.

[ODZKing]

Hello Matt, welcome from a fellow 73 400HP owner whose car originated in California.
First, here are a couple links to my website. You can download the parts manual, crash manual, Service manual and other information on there.
http://www.retrorarities.com/
http://www.retrorarities.com/images/1973MoparPartsCatalog.zip
http://www.retrorarities.com/1973-74ChargerCollision.pdf
http://www.retrorarities.com/images/73DodgeServiceManual.zip
http://www.retrorarities.com/ChargerInfo.htm
Now, part of your problem sound like ground, earth as you call it. Make sure there is a good ground from the battery ground to the block and another wire to the rad support (that is closest).
Also, the headlamps go through the high beam switch on the floor. If it is shorting for any reason or corroded, that is another issue. Replace it, they are inexpensive enough.
Next the headlamp switch ... you remove the knob/stem by pressing a button on top of the switch. Not easy to get to BTW, see pic below.
Then the nut on front which may or may not require a special wrench, depends on how handy you are. You will see once you're in there.
Hope that helps a bit, please don't hesitate to ask questions on PM me with thoughts. I'll help if I can.
Bob from Liverpool, NY.

[Matt73Charger]

Thanks Bob, that’s some helpful links.
I shall have a good look at the grounds you described. Yes sorry if there maybe some terminology differences   I’m still getting used to calling the boot a trunk, the wings as fenders and the cills as rockers, but it’s becoming second nature now.
One downside is obviously parts are easily available in the US, but seemingly cheap parts become rather pricey once international shipping and duties are factored, which is annoying.
My parts requirements list is growing the more I look around the car.

No headlining or bows, someone has cut the ralley cluster surround to fit an aftermarket head unit at some point, so now it’s just a big hole  
The heater fan does nothing, and it appears someone has removed the control valve in the engine bay and so hot air is continually entering the interior. And they deleted the A/C, removed the rear demister fan and added a switch by the dash which doesn’t appear to do anything, so have to trace that.

But I’m thinking changing the headlight units to H4 and H1 is certainly something that needs doing.

[Matt73Charger]

Delving further into the electrics at the moment. Seems someone has made some repairs with the wiring for the front side markers and fender mounted indicator signals.
I decided to not waste time reusing the existing repaired sections, so I'm just renewing the wiring from new for those parts.

Quick question though, can anyone tell me if the side markers are supposed to flash when you switch the hazard lights on? With the current wiring, the side markers flash when the hazards are on. I'm unsure if that is correct or if someone has wired things wrong at some point?

The way I see it from the wiring diagrams, is that the front side markers are simply a black/yellow (black/tan) wire for the positive going to each front side marker and a black ground wire. As for the fender top indicator signals, they have one wire for the positive which uses the same black/yellow (black/tan) wire as the side markers and the ground is taken directly from the fender using the ground contacts under the indicator base fitting.

Just want to make sure I wire things up as per OE and not wiring things wrong like someone has done previously.

Currently, when using the turn signal, the corresponding side fender top indicator blinks and the corresponding front park light. The side markers dont flash.
Using the hazard switch, the fender signals flash, as do the front park lights and so do all the side markers.

[Nacho-RT74]

Side markers are not made or wired to blink. It can be modified thought. Changing some wires could blink at the same time than front/rears when parking lights are off, and blink reversed with parkings on.

If they blink with hazzards but not with turning could be simply some ground deal. The high load hazzards suck could make to get a ground source from anywhere around the circuit due the lack of good local ground ( parking light housings ), like the radiator core support where all lights are grounded BUT front parking lights. So this stage could make dim slightly the sidemarkers like blinking because the sidemarker filaments will glow due the power going throught them up to the ground.

I hope this makes sense.

[Matt73Charger]

Thanks Nacho. Yes that makes sense.
As you've confirmed that the side markers shouldn't flash, someone has clearly done something with the wiring at some point, so now I can put it correct and also renew the grounds.

[Nacho-RT74]

But if the wiring was modified to blink with hazzards they should blink with turnings too, because hazzards and turnings are the same wiring coming out from turning switch.