Electrical/charging issue HELP

[snailgarden]

I’m facing an issue where my car (1968 Plymouth Valiant 100) is dying when the windshield wipers and blinkers are on while the car is in D with the brake pushed in. My car completely died while waiting to turn left at a light.

It wouldn’t start back up at all, wouldn’t even make a clicking noise. But it will start up completely fine in neutral. It’s just when I shift to D it’ll die again. It’s now done this two times (second time was just me in my driveway trying to recreate the initial issue).

I have replaced the ignition switch thinking it was that… before this, I replaced the battery, the alternator, and voltage regulator as well. It also has a new distributor, new spark plugs and wires. New ignition coil as well.

Could this be an issue with the neutral safety switch? Grounding issue? Or what? Any help would be greatly appreciated.

 

[RustyRatRod]

The neutral safety switch only allows the starter to engage in either park or neutral. So that part's normal. Are you saying it would not restart in park and only start in neutral? If so, that's likely a linkage adjustment issue. Other than that, the additional load on the alternator could be dragging the engine RPM down, but it should not be doing so. I'd check the battery first. If it's on the way out, that can put an additional load on the alternator and slow the engine down. Also check the idle speed. It should be somewhere around 750. Then just do a basic tuneup check. Ignition timing, check the point dwell if it has points, inspect the plugs. The carburetor might need the air screw(s) adjusted. It also helps us greatly to know what engine we're working on here. Details like ignition type, carburetor type. Is it all stock? Throw a bone or two at us, ok?

 

[snailgarden]

No it will not start while in park, only in neutral. But it doesn’t do this every single time. It’ll only do this when it’s been running for a bit of time.

It’s got a 4.5L 273 V8 engine with an Edelbrock 4 barrel Carb. The battery is brand new. It has gotten the following parts replaced, (also got a partial rebuild of the engine done, but I don’t know the exact details of it because it was done under the previous owner):

Cardone Distributor

Resistor (ballast) block

Felpro intake Manifold gasket kit

Murray 195 degree Thermostat and thermostat housing gasket

Gates Upper radiator hose

Gates Lower radiator hose

Ultima Alternator

Voltage regulator

MasterPro V-Belt 1/2 Inch x 53-5/8 Inch - 9530

Alternator belt

Water pump hose

Heater hoses

Power torque (engine) Motor mounts (2)

Westar Transmission Mount

Water pump and gasket

Fuel tank, hose fittings, hoses, gaskets

R45xls ac delco spark plugs

Accel Super stock ignition coil

Accel super stock plug wire set

Fel-Pro coolant outlet gasket

Brake best wheel cylinders (front and back)

Brake best Drum brake shoes part 333 for front 10 inch and 329 for rear 9 inch

Ac delco drum brake shoe hold down

Drum brake hoses

Best brake drum hardware

Edelbrock carb mount

4-barrel edelbrock carb (added by previous owner)

Standard Ignition switch

 

[snailgarden]

I forgot to add all new spark plugs and fuses as well.

 

[RustyRatRod]

Ok all that helps. Thanks. Keep an open mind here. "NEW and "GOOD" have different definitions. Remember that and test accordingly. It sounds from your description as if the alternator is working hard with some accessories turned on and dragging the engine RPM down. "MY" first suspect would be a bad battery causing the alternator to charge at a high amp rate. It is also one of the easiest things to check. The alternator and charging system. And of it is a faulty battery, that's a very simple fix. I go with the simple stuff first. Rule that out and go from there. Do you have access to a "good" charging system tester and more importantly someone who actually knows how to use it? If so, my first recommendation is to have the battery and charging system tested and NOT by who you bought the battery from.

 

[67Dart273]

Along with above, you might rig, at least temporarily, a voltmeter so you can see what the system is doing. "For now" see if you can find someplace to plug it in without hacking the wiring. The fuse panel, or maybe the radio connector. Just buy a small pack of the flat "flag" connectors and stick one in the red wire on the radio connector. You can live without a radio for a few days LOL.

Make sure it goes off with the ign switch, or it will be a drain when the car is shut down.

 

[Bewy]

Sounds like two problems:
[1] Only starts in N. Sounds like switch or linkage adjustment.
[2] Stalling in gear. Could be many things. If it is a points dist, check the gap 0.016-0.019", not critical. Then check the ign timing. Not sure what it is for that engine, but 8-12* BTDC is pretty safe. Could also be carb problem, flooding, float level etc.

 

[Dave999]

just to discount a potential problem
undo clean and do up both ends of the engine earth strap, should run from block to bodywork somewhere around the mounting rubber at one of the engine mounts

the engine doesn't run well with no earth and i'm wondering if its earthing through the neutral safety switch when in N and losing its earth when in D...

if it has a poor earth cable the current flows through the radiator and the throttle cable.. neither of which is a good earth

its probably not this...but if you try to start a car with a bad earth strap you certainly get similar inconsistent behaviour, and it costs nothing but a little time to discount it as the cause.

other things.
aftermarket battery clamps. if they bolt onto the cut ends of the heavy gauge wire as a replacement for the original crimped and welded pieces, remove clean back to bright copper and put back on, batteries breath acidic fumes and the first thing that corrodes is an open junction between the cable and the connector, which is probably why they were crimped and welded originally.
if you car has been subjected to a shoddy replacement of the main feed from the battery up the inner wing heading for the bulkhead just check any none standard junctions in it have not turned to green dust...... green dust rather than nice shiny connector will show good voltage at fuse box but a total inability to flow any current... as soon as you try to start the car you will get a total brown out of everything including power to the ignition.

earth strap and corrosion issues get better and worse with dampness or humidity. works one day and a change in the weather makes it very bad the next, because moisture and green dust, does conduct electricity better than just dry green dust... Your wires will be getting very hot at the connections if you have a problem caused by corrosion of connectors


the ignition switch replacement made some sense here, but don't throw the old one away just yet....

Dave