Well as the title said. I get a decent spark when I connect my neg battery lead up and after cranking for say 3 seconds that F'er gets HOT. My thought is I have either a bad ground (possibly my rear head ground strap has some engine enamel in the thread on the rear cylinder head??) or something else. But the spark isn't huge, just noticeable to make me wonder

 

Sounds pretty normal to me.

 

Thanks for the sanity check. This was a major 3 year project and never taking the time to think or check what happens right after crank I've wasn't sure if that heat was normal. BUT, if I consider the amps going through the circuit at time of start it does make sense.

 

A small spark is normal, a huge spark would point to something drawing amps even if the car is off (radio, amp, capacitor). You want to make sure you find it because it would drain your battery overnight.

If one battery terminal is getting hot and the other doesn't, check the terminal. If it has a bad connection, it WILL get hot to the point that it will burn your fingers. Bad connection is extra resistance. Increased resistance increases voltage over it. Increased voltage times high current = lots of watts = lots of heat.

Hope this helps.
Lou

 

My negative does get hot enough to scorch my finger. What's the resistance I should be seeing on my VOM when checking? I'd check this against the battery + terminal with lead connected and the - battery lead disconnected from the terminal right?

 

You could put one DMM lead on the block and one on the battery post (with all cables connected) and you should see resistance at almost zero. I mean, 0.01 would be nice but if you see 0.1 or higher, it's a problem.

Also, make sure to check the battery cable terminal on both sides, i.e. not only the terminal connection to the post but also the connection to the cable. Especially aftermarket terminals show problems in that area.

Lou