Engine not cranking well... Bad body ground or battery possibly?

[72ChargerHawkeye]

Okay so I am at a loss. I have a 72 Charger base model with a 78 360ci 4bbl. I recently removed my alternator to remove and replace my fuel pump that was cracked. After I put everything back together I cranked over the engine for awhile to get fuel up to the carb. After all this cranking I swapped out the battery as it took a lot of juice to get to that point and got it fired up. Once it was running reliably after tuning the carb in I pulled the current battery and put the original one in to charge it back up. I left the car running for about 45 minutes to an hour. The next day I came out to fire it up and when I did the cranking was really sluggish to the point of not firing. When I opened up the hood I saw the body ground from the battery to the radiator support was smoking from an old but splice that a previous owner had made. So at this point I figured it was a bad ground. I put a charger on the battery overnight at this point figuring that it wouldn't hurt to have a fully charged battery. Next day, I replaced the body ground cable with a new 10 gauge cable. Cranked the engine over and fired right up. Let it run for about 15 minutes while I tinkered with some other non-electrical stuff on the engine. Shut the engine off. After about 5 minutes I tried cranking back up again and it is back to a sluggish crank without firing but no smoking body ground yet. Any thoughts on where I should begin or what the problem could be?

 

[66Satellite47]

Sounds like a new battery is in order. Also be sure you have a good ground from block to body. Make sure connections are clean.

 

[eldubb440]

how old is the battery? they puke about 4 years in

 

[66Satellite47]

Battery's are weird sometimes. If it doesn't take a good charge after many hours, time for a new one.

 

[747mopar]

Your ground to the radiator should have nothing to do with cranking, your negative cable going to the block should do the work not the body ground. The fact that your frying the body ground makes me think your problem is in the main ground to the block, check the connection. Also an easy way to find the problem if you have a voltmeter is test at the battery post (Not the cables but directly on the post) then have someone hit the starter.... if it maintains 12V your battery isn't the problem. Next test at the battery connections, if you see 12V both while sitting and cranking keep moving down the line. A bad connection often will read 12V until a load is placed on it so grab a meter and a friend and have at it.

 

[threewood]

I had a slow crank issue that was traced to a crappy molded positive battery cable. The cable was loose in the clamp (factory style re pop). Worth it to check. Made the cable and ends hot as hell.

 

[Glenwood]

I had a slow crank issue that was traced to a crappy molded positive battery cable. The cable was loose in the clamp (factory style re pop). Worth it to check. Made the cable and ends hot as hell.

While at a local show a few weeks ago, a guys duster was turing over slowly and would not start. The positive cable was loose in the the molded clamp and fell out when tugged and It was a new cable!

 

[Dennis H]

Agreed. Simple things first. Cables. Connections. Point of info, 09 Challenger has original battery.

 

[oldbee]

Agreed. Simple things first. Cables. Connections. Point of info, 09 Challenger has original battery.

Yahoo, it'll probably die tomorrow morning!

 

[Pops1967GTX]

just to eliminate... Put a socket on crank bolt and turn engine by hand to see if it turns freely..

If you ran the engine And it was Hot & slow cranking . Look at voltage drop also.."temperature induced" resistance in the starting circuit.

 

[threewood]

While at a local show a few weeks ago, a guys duster was turing over slowly and would not start. The positive cable was loose in the the molded clamp and fell out when tugged and It was a new cable!

Probably the same manufacturer. I tried to re solder it and the alloy they use melted away into nothing.

 

[oldbee]

Dennis could be the exception, ya never know. Especially with electrical stuff!

 

[72ChargerHawkeye]

Your ground to the radiator should have nothing to do with cranking, your negative cable going to the block should do the work not the body ground. The fact that your frying the body ground makes me think your problem is in the main ground to the block, check the connection. Also an easy way to find the problem if you have a voltmeter is test at the battery post (Not the cables but directly on the post) then have someone hit the starter.... if it maintains 12V your battery isn't the problem. Next test at the battery connections, if you see 12V both while sitting and cranking keep moving down the line. A bad connection often will read 12V until a load is placed on it so grab a meter and a friend and have at it.

I went through last night and cleaned up all the contacts from the battery to the grounds and from the battery to the starter and starter relay. It seems to mostly be functioning as normal now except for every couple turns of the key it just clicks and nothing. I turn the key back off and turn to fire it again and it works. Any ideas on what this might be? I know my + contact on the starter was really corroded and I believe that was the start of my problems before but now like every 5 turns it just clicks.

 

[747mopar]

Without using a meter your just guessing and cleaning. Using a battery post cleaning tool will ensure a better connection since they ream the clamp and scrape the post at matching angles (be sure to spread the clamp prior to reaming). Over the years corrosion, being left loose and being twisted back and forth all take a toll on the battery connection leaving gouged, pits, etc... Other than that inspect for deformed terminals, use some type of electrical grease on the connections and if you have those cheap battery cables with the little strap over the wire (non molded) throw them away and get a good set. Sounds like you touched on the problem along the way but didn't get it good enough, I'm betting a poor fitting battery clamp.