I've been getting intermittent M&S lights, so I'm trying to figure out if anything's off with the battery and charging system. I'm getting 12.63v off the battery cold, and 14.2v when it's running. This all seems normal and correct—but is it?

I also did a parasitic current test, and was getting 17.8 mA of current (putting the multimeter in series with the negative battery terminal). That seems high-ish. Is that an acceptable level? I tried unplugging a new amp I recently installed, but it didn't affect the current draw at all. The interior lights weren't on.

I think my next suspect has to be a bad ground somewhere. The negative battery terminal itself is sort of loose, though I'm not sure how to fix that. The bolt on top is cranked down all the way, but it's still not completely tight when cold. I can pull it off with my hand. Any tips or thoughts? I'll also check other grounds.

Thanks as always!

 

Battery posts have to be rock solid. I'd drop a little shim in there or some sort, see if that clears things up straight away.

I can't remember the acceptable current draw but yours seems a touch higher than I would expect.

 

Thanks! Good idea about using a shim of some kind. I'm sure I can find something that will work.

 

Also, just re read and noticed the bit about the M and S flashing. Missed it somehow. Probably the Sunday afternoon drinking.

I had the same, intermittent M and S. Fixed by sorting a bad connection at the battery. As long as there are no other symptoms. I'd wager that's it.

Would be good to confirm the m/a draw amount though. I'm sure it was 0.3 ma or somethings that's normal. Not a full 17.

 

Use a wire brush to clean the inside of the battery terminals and the battery posts. Also, make sure the top of the battery is very clean. Use a solution of dish soap and watter to clean it. I have seen dirty batteries cause parasitic draw before. Also, if your battery is old, (4+ years), you probably need a new battery. I had an old AAA battery for 4 years and I started to get intermittent M+S lights once it was starting to crap out on me.
I hope this helps.

 

I cleaned up the negative terminal and reinstalled it, and that cured the M&S lights for a bit. They came back after a week or so, though. I'm having lots of trouble finding a shim to fit in there. The negative terminal clamp has an odd mechanism that only allows a small amount of give when it's undone. I tried prying it apart with a screwdriver and slipping in a piece of hose clamp, but to no avail. Any suggestions? I know there are purpose-built battery post shims, but I'm certain the terminal clamp won't get wide enough to fit around them. I've been looking around for some sort of conductive paste, but I'm not finding anything.

 

These are similar readings to the readings on my Ultragauge.

 

To shim my battery clamps I simply drove a small screw in between the post and the clamp. I did it to both the positive and negative sides.