Electrical issues

-
V8 Sam

V8 Sam

Well-Known Member
Joined
Sep 16, 2012
Messages
151
Reaction score
39
Location
United Kingdom
Dodge is running for the first time in years.

Infact it's running so well it no longer turns off on the key

Have to smother carb intake in order to kill it.

Any ideas? Before I start looking into it. I'm thinking maybe the ignition switch.

When you connect a battery terminal the 'oil' light comes on on the dash as if the ignition is switched to on. But without a key in the ignition.

Then flick key to on position and oil light flickers a little but stays on. Then flick to start and it fires up. Switch it back off and take key out does nothing.

On a side note wipers and indicators no longer work either, don't know if related or separate. Main lights work fine.
 
Year? Model? Options? 100% original? If not, what's been done to it?
Switch or miswired.
Switches and wiring changed from year to year.

Almost all A-bodies:
Key On, engine will show slight discharge from battery to power ignition, brake if on, and at least some oil indicator.
Key off, ammeter should show no discharge unless brake is applied or lights are on (including overhead dome).
Wipers and turn signals are usually powered from the 'accessory' circuit from the key switch. Wiring gets a little more complicated toward the end of the run.
 
bad or miswired starter relay maybe
like Mattax said, look to your switches and wiring
 
Oh yeah sorry I should've mentioned

70 dart.

The wiring is a bit of a Mish mash over the years,.runs a Lucas type alternator that is internally regulated.

Never had an issue with that before though.
 
Well that could be the problem. You'ld have to show us the wiring.
If the alternator's rotor gets power through its internal regulator, then depending on how its wired, it can also feed the ignition.
When AMC started using internally regulated alternators, a resistor wire was put between the ignition and the field wire. That was for vehicles with ammeters. The others got an idiot light with resistor in parallel. Did pretty much the same thing.
 
'70 Ignition in column. Additional connection at the steering column. Could be cross wire short somewhere in there too.
I'd suggest disconnecting the battery from earth and positive and trace what connects to what.
Use a continuity setting on a multimeter or equivalent. Put what you find on paper.
begin with the Battery feed/charge wire. There should be continuity all the way to the steering column connector.
Disconnect that connector. Check for continuity between the power feed and each other position. Turn the key to run, do the same, then accesory, and then start.
If that all checks out, then continue checking for shorts between 'battery' and ignition in the harness. Continuity between the power wires and the ignition wires is a short (key switch disconnected).

'Battery' is in quotes because the alternator is the power source when the engine is running. But the alternator output wire and battery output wire are tied together. So its really the power circuit but its almost always called 'battery'. Even the alternator output post is marked Batt on a Chrysler alternator housing.

upload_2020-5-8_9-3-18.png
 
V8 Sam said:
Dodge is running for the first time in years.

Infact it's running so well it no longer turns off on the key

Have to smother carb intake in order to kill it.

Any ideas? Before I start looking into it. I'm thinking maybe the ignition switch.

When you connect a battery terminal the 'oil' light comes on on the dash as if the ignition is switched to on. But without a key in the ignition.

Then flick key to on position and oil light flickers a little but stays on. Then flick to start and it fires up. Switch it back off and take key out does nothing.

On a side note wipers and indicators no longer work either, don't know if related or separate. Main lights work fine.
Click to expand...

Disconnect your battery when you are not intending to start the car, because you have something in your ignition circuit wiring connected direct to 12v.
This is why your oil light comes on when the battery is connected, and also why it won't shut off.

Just for kicks disconnect the alternator field wires when the keys is off and see if the motor shuts off.
If it does this will narrow down where the problem is substantially.
Also, when you want it to shut off, disconnecting the battery should shut it down instead of flooding the motor and washing down the cylinders of oil.
 
Or, if you want to stop it, play coil roulette and try pulling the coil wire from the coil. :rofl:

Seriously, X2 on what Trailbeast said. Do you have a voltmeter? With the key off, check for voltage on the field terminals.
 
You must log in or register to reply here.
-

Back
Top