No start but head lights work

[Doug Larsson]

I have a 1973 Dodge Charger I checked the continuity of the neutral safety switch back in April it was fine but I changed the harness. But I've had some issues when I disconnect the battery when I'm working on the car .When I connect the battery it won't start but if I put it in neutral it starts. Except this time I changed the heater core and connected the battery and now it won't start at all any trouble shooting advice would be greatly appreciated.
Thank you

 

[miller]

When I connect the battery it won't start but if I put it in neutral it starts.

Are you saying it will turn over, starter working, but won't fire off?

Either way, the wiring circuits are only tied together via the ignition switch. Go to the basics, and start from the switch, checking for current. From the switch to the starter, and from the switch to the coil.

 

[Doug Larsson]

No turn over dead the buzzer goes off when I put the key in and the dome lights on .

 

[Lionized]

Try jumping the studs on the starter. If it'll turn over, it's your relay.

 

[HEMI-ITIS]

Is the key switch sending a signal to the relay in park?

 

[Doug Larsson]

Try jumping the studs on the starter. If it'll turn over, it's your relay.

I have a minI starter on it and the studs are towards the block with my headers the fit is real close to it so I don't think it's possible to do that.

 

[Doug Larsson]

Is the key switch sending a signal to the relay in park?

I haven't gotten that far yet just got off work I'll check later in the afternoon when I wake up.

 

[HEMI-ITIS]

Jump it at the starter relay,also check key power to the relay.

 

[HEMI-ITIS]

You should be sleeping NOW!!

 

[Doug Larsson]

You should be sleeping NOW!!

I work grave yard.

 

[Doug Larsson]

So far I got the starter to turn over when I jumped it but I'm still trying to figure out how to check the ignition switch to the relay to see if it is the relay.

 

[miller]

Two wires to look at, on the starter relay...yellow (should be wire from the ignition switch)...when key is on the 'start' position, the yellow wire is hot. Also, the brown wire next to the yellow. The brown wire is from the NSS, and should get grounded in both Park and Neutral.
Also off the starter relay, besides the larger gauge wire/cable, is a smaller wire that goes to the starter itself. You can check it to see if it gets power, when the key is turned to start. Start position on the ignition switch is the only time some of the wires on the starter relay are hot.

 

[Shorthorse]

So far I got the starter to turn over when I jumped it but I'm still trying to figure out how to check the ignition switch to the relay to see if it is the relay.

You might need two people. Get a test light or voltmeter (a must) and have someone turn the key to the full start position. You are looking for 12 VDC on the yellow wire at the starter relay, terminal 'I". If you do not get 12 VDC there, you are going to look back toward the ignition switch. Pay special attention to the connections on the bulkhead terminal. Mopar bulkhead terminals are notorious for having faulty or marginal connections.
The first thing to do is the easiest, make sure your motor is well grounded. You said you were working on the heater core. When you were in the engine compartment, did you remove any engine to firewall ground straps?
http://www.mymopar.com/downloads/1973/73CoronetChargerA.JPG
http://www.mymopar.com/downloads/1973/73CoronetChargerB.JPG

 

[mopar 3 B]

Grounding was also my first thought. The little ground wire to the core support maybe all the headlights need but the ignition module and starter require good battery to engine and engine to body grounds.
I have seen starter replaced when all that was needed was a clean battery to engine ground.

 

[miller]

Alright...bunch of good info...quit messin' around...and let's hear that thing fire off!

 

[Mopars & Missiles]

Try jumping the studs on the starter. If it'll turn over, it's your relay.

Not necessarily.

 

[Doug Larsson]

So I changed the relay still nothing some thing must of came off when I was taking the heater box out or the blower motor it just makes no sense this is going on.The starter is practically brand new it only has 2000 miles on it.

 

[HEMI-ITIS]

Did you use a test light and check before you changed the relay?

 

[Doug Larsson]

Found the problem some how and I don't know how because it's not even close to the heater box the harness came loose grrr. When I was a service tech in refrigeration you always looked for the obviuos why I didn't do that working on this car is beyond me .

 

[Doug Larsson]

Not necessarily.

Yep I can attest to that lol .