Stupid (-) ground question

[N2Clsx]

So after 6 months or so the tranny, transfer can and engine are back in on my sons 72 Blazer. I just wanted to crank the engine over without starting it to run some oil though it and make sure everything is ok.

Well the ground was hooked up to the A/C unit which I cant mount yet until the valve cover is on so I held the ground to the block to crank it over and the ground wire got very very hot and the engine cranked over slowly. Battery read at 12.02 volts. Was this because of a poor ground or poor ground and a low battery? Help.

[rsavage]

Bolt the ground to a cleaned up area on the front of the cylinder head (short bolt about 5/8 to 3/4" long. Make sure you have the two smaller ground straps refastened to the engine from the firewall. Pull the plugs out of it so that it spins over easier/faster.

[Critter]

Originally Posted by N2Clsx

Was this because of a poor ground or poor ground and a low battery? Help.

Yes, that was a poor ground. All the amperage required to turn the engine over was having to flow between the block and the end of the terminal at a very small contact point (which might have been painted or dirty making things even worse).

Originally Posted by rsavage

Bolt the ground to a cleaned up area on the front of the cylinder head (short bolt about 5/8 to 3/4" long. Make sure you have the two smaller ground straps refastened to the engine from the firewall. Pull the plugs out of it so that it spins over easier/faster.

Rsavage is right. Bolt everything up and you should be fine. Remember unless you are going for a concours restoration under your hood you can never have too many grounds in this situation. Feel free to add a few more if you like. I like to run the ground cable from the battery to the head/block, then I run a smaller wire from the block to the frame and another smaller one from the block to the firewall/body. That will pretty much cover everything.

[N2Clsx]

Thanks. It was cranking over now no spark. going out to figure out the problem right now. wish me luck.

[N2Clsx]

Just some new bad luck info that was fixed. First off this my sons first vehicle that my wife gave him. He is 17 and we pulled the engine,tranny and transfer case out to be rebuilt. Tranny was sent out to be done and he and I rebuilt the engine. After a few months all was back in and hooked up ready to go...... untill ignition time. First off the eddelbrock intake decided to spring a water leak about the size of a pencil at the right rear. Then then the water pump that didnt leak now decided to go bad. Then the tranny coolant lines decided to let loose and spray fluid everywhere. All of the was fine when we parked it. Well another day and a few bucks later it is running. Off to the muffler shop tomorrow to have everything hook up to a new set of Dougs that he bought. As my son said, If it can go wrong it will right now.