70 Duster Ignition Switch Test

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mickey_bigdaddy

mickey_bigdaddy

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How can I test the ignition switch on the steering column with the connector? I assume there is a test method for the switch using a multimeter.
 
Factory service manual should provide details. I'll put here what I think I know. I may need to correct myself after I have more coffee.
Switch disconnected from cars harness, testing with Ohms meter. Switch in run position shows connection to all except brown and yellow. Switch in start position shows connection to both brown and yellow.
 
I looked in the Electrical section in the FSM for 1970 and I did not see an ignition switch test. I'll try what you said here.
 
I would recommend you test for voltage with everything connected. A ohms test is not conclusive because a connection can have continuity and not carry a load. Imagine a battery cable with a single strand of wire. It would show continuity but not carry a 150 amp load of the starter. Search for a wiring diagram of your system that will show what wires have power with the switch in each of the positions. Also, it would be helpful if you stated what the nature of the problem is that you are wishing to diagnose.
 
It's a no start. I'm going through the whole circuit. I can turn the the engine by jumping the starter relay switch but not with the ignition switch.

And I do not have spark at the spark plugs.
 
Large Red = battery feed Connect to red lead of meter
Yellow = starter solenoid crank position
Brown = Ignition crank position
Blue = Ignition run position
Black = ACC run or ACC position
Ohms reading should be very close to zero.
As stated earlier recheck with voltage.
 
I don't know how I'm supposed to recheck with voltage. That means I have to reconnect the connector......then what?
 
mickey_bigdaddy said:
I don't know how I'm supposed to recheck with voltage. That means I have to reconnect the connector......then what?
Click to expand...

Use a straightened paper clip to probe the backside of the connector. If your good there you need to check for voltage at the starter solenoid, ballast resistor and coil. The red, yellow, blue and brown wires also run thru the bulkhead connector.
 
mderoy340 said:
Large Red = battery feed Connect to red lead of meter
Yellow = starter solenoid crank position
Brown = Ignition crank position
Blue = Ignition run position
Black = ACC run or ACC position
Ohms reading should be very close to zero.
As stated earlier recheck with voltage.
Click to expand...

Ok, so let me get this straight.

Continuity Check:
1. With the multimeter, set it to CONTINUITY.
2. Connect the RED lead of the multimeter to the RED wire in the connector.
3. Probe each wire, using paper clip; YELLOW, BROWN, BLUE, BLACK.
4. All readings should be ZERO.
Question: Do I need to turn the key to each position to test this?

Voltage Test:
1. With the multimeter, set it to 20 VDC, larger than the 12 VDC battery.
2. Connect the RED lead of the multimeter to the RED wire in the connector.
3. Probe each wire, using paper clip; YELLOW, BROWN, BLUE, BLACK.
4. I assume that the key needs to be in the proper position for each to actually get a voltage reading. Is that correct?
Question: I assume a correct voltage reading should be, 12V. Is that correct?
 
mickey_bigdaddy said:
Ok, so let me get this straight.

Continuity Check:
1. With the multimeter, set it to CONTINUITY.
2. Connect the RED lead of the multimeter to the RED wire in the connector.
3. Probe each wire, using paper clip; YELLOW, BROWN, BLUE, BLACK.
4. All readings should be ZERO.
Question: Do I need to turn the key to each position to test this?
Yes
Voltage Test:
1. With the multimeter, set it to 20 VDC, larger than the 12 VDC battery.
2. Connect the RED lead of the multimeter to the RED wire in the connector.
3. Probe each wire, using paper clip; YELLOW, BROWN, BLUE, BLACK.
4. I assume that the key needs to be in the proper position for each to actually get a voltage reading. Is that correct?
Yes
Question: I assume a correct voltage reading should be, 12V. Is that correct?
Click to expand...
Voltage reading should be the same as battery voltage.
 
Continuity Check:
There is continuity for all the wires when I turn ignition switch to the proper positions.

Voltage Test:
No voltage on any wires when I turn ignition switch to the proper positions. All fuses are new.
 
I pulled the instrument panel out and the ALTERNATOR INDICATOR is NOT connected. The PO didn't connect the power and ground wires back up. I checked voltage across the two wires that are sitting there loose and viola, 12 V reading.

Reconnected the ALTERNATOR INDICATOR and retesting the IGNITION SWITCH.

Voltage Test Results:
 

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hey man. forget continuity. check it in place with hooked up

you have seat belt interlock?
 
Those readings are with the connectors hooked up.

I don't know if the seat belts have interlock. What year was that added in? I'll look.

I wonder if the NEUTRAL SWITCH is affecting this in any way.
 
These readings don't look right.

Shouldn't they be 12.5 V and not those really low 0.2 and 0.3 V?

And why is the IGN RUN Blue wire 12.5 V in the OFF position?

I just bought a new ignition switch but I want to make sure before I install it.
 

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I bought a new ignition switch and tested it before I installed. I still don't know what readings I should have and where to go from here.

I assume that the neutral safety switch is keeping the Yellow wire from showing voltage. I have a 3 speed manual floor shifter in the car right now. Where would the NSS be located? Help please.

The readings are as follows:
 

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Update: The primary side is good from the BATTERY up to the BALLAST. I just got the starter to turn over with the ignition key. Main issue was that the wires to the AMMETER were disconnect to the AMMETER itself. I went ahead and reconnected them and got the starter to turn over with the key.

This is the backside of the dash and the AMMETER connectors.
 

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I did change the BALLAST and the STARTER SWITCH RELAY just because they looked pretty crappy old.

Primary circuit picture from Mopar training video below, missing the CLUTCH STARTER SAFETY SWITCH and I find that odd since the clutch pedal needs to be pressed in for the starter to fire off. But, its just a picture so I guess no harm done.
 

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While I had the AMMETER wires out, I added a kill switch. Works great.

Dorman Part #84830. It's a 25 amp switch so I assume it can handle the load.
 

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mickey_bigdaddy said:
I bought a new ignition switch and tested it before I installed. I still don't know what readings I should have and where to go from here.

I assume that the neutral safety switch is keeping the Yellow wire from showing voltage. I have a 3 speed manual floor shifter in the car right now. Where would the NSS be located? Help please.

The readings are as follows:
Click to expand...

By the way, these readings never made any sense to me. I just figured out which wires went where and made sure they were okay.
 
Did a check on the coil, condenser and points. Found that points were bad. Changed them and now I have spark at the plugs.

Thanks to all.
 
mickey_bigdaddy said:
Voltage Test:
1. With the multimeter, set it to 20 VDC, larger than the 12 VDC battery.
2. Connect the RED lead of the multimeter to the RED wire in the connector.
3. Probe each wire, using paper clip; YELLOW, BROWN, BLUE, BLACK.
4. I assume that the key needs to be in the proper position for each to actually get a voltage reading. Is that correct?
Question: I assume a correct voltage reading should be, 12V. Is that correct?
Click to expand...

Just as an FYI, this procedure was not correct. Connect the black lead of the meter to chassis (ground) and the red lead of the meter to the wire under test. The wire under test should read 12VDC when the appropriate key position is selected.

Glad you got spark now!
 
nm9stheham said:
Just as an FYI, this procedure was not correct. Connect the black lead of the meter to chassis (ground) and the red lead of the meter to the wire under test. The wire under test should read 12VDC when the appropriate key position is selected.

Glad you got spark now!
Click to expand...

Ok, thanks. I redid the tests for curiosity sake and here are the readings:
 

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Well, I got the engine to start pretty easy after all this. Just had to throw in a little starter spray and get the fuel to fill the carb and it started pretty quick.

Thanks again to all that helped.
 
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