Just bought 70 Challenger...and it's (electrically) dead. Any suggestions?

[Project70]

Hello CC Members - glad to be here.  After a couple years of asking my neighbor finally sold me his 1970 Challenger, 440 Auto (originally a 318 car), which hasn't been tagged or driven on the streets in a decade.  He has run it occasionally (I've heard it) but didn't drive it for various reasons that are his business not mine.  It probably hasn't run in at least a year, so when I bought it last week I put in fresh fluids, gas in the tank, a new battery, then I turned the key and was very disappointed.  Here is what I'm experiencing:

1) Connect battery and see 12 volts at the terminals, putting a voltmeter on the negative terminal and positive input at the wheelwell mounted solenoid I get 12.5 volts
2) Lights, radio, horn function
3) Turn key; starter whirs but doesn't actually turnover
4) All electrical then dies...I mean NOTHING.  No horn, lights, radio, nothing.  As if there is a completely dead battery.
5) Disconnect battery, wait somewhere between 15-30 minutes and reconnect battery, again have lights, horn, etc.
6) Turn key, everything dies again, NO POWER

Any thoughts on where to start?

Thanks!

[Rich G]

First place to start is a load test on the batteries and then a volt drop on the battery cables. Just because you have 12 volts on the battery doesn't mean it can handle a load. Id bet the problem is there since everything shuts down when a load is applied.

[Project70]

First place to start is a load test on the batteries and then a volt drop on the battery cables. Just because you have 12 volts on the battery doesn't mean it can handle a load. Id bet the problem is there since everything shuts down when a load is applied.

Thanks for your reply, Rich.  I bought\installed a brand new battery Sunday night and when the aforementioned problem happened I had the same thought as you...bunk battery, so I took it back to the auto parts store and even though it tested good insisted on another new one.  When I first connected the 2nd new battery and turned on the headlights they were fully lit, not dim.  One turn of the key and everything (including horn and radio, really minimal draws) is nonfunctional.

[4Cruizn]

Not that I'm the expert in this area but did you try to jump out the starter solenoid to see if the starter will engage? 

[ChallengerHK]

Check/bypass the fusible link.

[Project70]

Jumping at the solenoid gave the same result as turning the key - it will click once then all power is off.

Good suggestion on the fusible link.  I checked power on the backside of it off the solenoid earlier and it was fine, but a wiring diagram I just found shows a second fusible link - I'll check that tomorrow.

There are a lot of new parts on this car and I know it has potential but electrical problems are the worst for me...I'd rather pull the motor tear it down than chase down these kind of gremlins...

[footin70rt]

Make sure all connections at the starter solenoid are clean and making good contact, double check battery cables for corrosion. Bulkhead connector where the main power lead goes through is a common problem, it gets hot and over time corrosion starts to build up. Disconnect it and check for melted terminals.       

[dutch]

mine had the same problem when I bought it. Turned out to be a bad / burned terminal in the bulkhead connector.

[cudagirl4406pk]

My cuda did that years ago and the connector between the steering column and the main harrness had a short and everything would die check that connector and make sure it is a good connection.

michele

[E-Body Products]

The electrical system is designed to turn off all accessories (lights, radio, horn, etc) during crank. It doesn't mean you have a bad electrical system because you have noticed this. Plus, during crank you are hearing the starter whirl.


Daniel
www.ebodyproducts.com

[Bullitt-]

The fact that jumping the relay causes the problem makes me think that the problem is in the main battery cable, probably where it connects to the battery. Bet you have a replacement connector on there. I replaced a battery once and it turned out to be that. 

[Chryco Psycho]

Check ammeter connections also but that should nto affect the starter

[MEK-Dangerfield]

I'll throw more mud against your wall of possibilities. I experienced the same issue this year and thought it was my 8 year old battery. It wasn't. It was my negative battery cable. It looked good on the outside, but green slime on the inside. Brads70 had the same thing happen to his positive battery cable.  So...As was suggested, check the connectors on both cables, and make sure the other ends are nice and tight to the block and starter.

[jimynick]

Make sure all connections at the starter solenoid are clean and making good contact, double check battery cables for corrosion. Bulkhead connector where the main power lead goes through is a common problem, it gets hot and over time corrosion starts to build up. Disconnect it and check for melted terminals.   

Clean the battery cable connections, take the cables right off and make it all nice and shiny and do the same thing to the ground strap on the engine before you get any deeper. Eliminate the easy variables first. Also, try snapping a set of jumpers on it and see if that changes the way it acts. Good luck. 

[Rich G]

Doing a volt drop on the cables will tell you if they're good or not. Where is the neg. hooked up to? If you can't even crank it by jumping it at the starter you have to be losing voltage somewhere. If the ground is bad nothing will work under a load. Do your volt drop right from the battery to the starter itself first.