I did the battery relocation last year, and it seemed to be OK throughout the summer and into the fall, but I did notice it getting weaker later in the year. Now, Datamaster is showing that it is only charging at about 13.0 volts while running, and before cranking it shows about 11.0 volts. It still has enough juice to crank it, but just barely and it luckily has caught and fired every time so far. However, it is getting a bit concerning to me that it may strand me somewhere.

Anyway, the basic setup goes like this: The Optima Red-Top is in a battery box in the rear area. The main cable from the positive terminal is 0/1 gauge and runs up to a distribution block on the front passenger side fender, pictured here:

http://home.mchsi.com/~shortb2002/distributionblock.JPG

The 0/1 comes in from the left, and it splits from there. The upper left cable goes to the stock power distribution block, the upper right cable goes to the alternator, and the one on the bottom goes to the starter. Those are all the stock cables just cut from the stock side post terminal. So I think the alternator cable is a 6 gauge and the starter cable is a 4 gauge.

The battery is grounded in the back to what looks to be a solid ground point at the bottom of the spare tire well using another 0/1 gauge cable hooked to the negative terminal. The stock negative cable is grounded here:

http://home.mchsi.com/~shortb2002/groundcable.JPG

(sorry for the big and blurry pic) It is the copper terminal and it grounded to a stock grounding post there. So I think I'm OK on that.

Any suggestions? The alternator tests out fine. Should I run a cable all the way from the alternator back to the positive post of the battery? Anyone have any experience with this?

Seems like it'll start up better after it sits for awhile, but if I run the car for awhile and stop it, then try to crank it up a few minutes later it is weak. The Optima seems to be OK also. Any help or ideas would be much appreciated. TIA.

 

More grounds will help.
Do a ground from the battery to the engine block if possible.
If not convinient to run a cable from the rear to the block then add another ground back at the battery to another spot on the body. More grouding is always a big help.

And in the mean time a few overnight charges of your battery might bring some life back into it if it's getting tired.

hth
Karl Ellwein

 

Well, I'll be lucky to get another helpful reply in this forum....

Either way, yes, I was considering running the ground from the battery to the subframe bolt below it to see if that would help. I guess my main concern is with the alternator cable though. Does it look like an OK setup to get a charge back to the battery? I've read of others running a 4 gauge cable or so all the way from the alternator back to the battery, but I thought I'd be OK because this setup is basically running an 0/1 back from up front for charging. Anyone else want to chime in?

 

What did I say wrong that offended you?

Sorry I didn't answer your direct question. Yes your + wire routing looks good and it is more than adequate.

The grounding could be improved. Or in other words, that's my opinion and suggestion.

4 gauge should work fine too for + and really is all that is needed. But in never hurts to over do the grounding.

Karl

 

Another vote for more grounding. In particular, it may be enough to simply get a good ground from both cylinder heads to the chassis. Use 4ga or 2ga grounding strap, and make sure both points of connection are clean (bare metal).

If you want to illustrate this, measure the DC voltage from the engine block to that ground point in the back, and I'm betting it's significant.

Todd

 

Nothing, the post had gotten moved from LT1 Tech and I thought it would have been better to stay in there as the question wouldn't be well suited for those with other generations of f-bodies.


Thank you both for the opinions. I didn't realize that additional grounds may be of help in this situation. I'll check into possibly adding some grounds. However, since the heads are aluminum, would it still be beneficial to run grounds to them?

 

yes

ground the heads, and a ground from a bellhousing bolt to the frame/body should be pretty good, but, the more the better




personally, I would have run the big cable strait to the starter, then ran a 6 gauge from the alt to the starter, then ran a 6 gauge from the starter to the dist box on the fender



is the ground stud on the fender clean and tight?

 

oops sorry, I see what you are saying about being moved.

Also, aluminum is a good conductor. It's just not magnetic. (At one time I wondered about that too and then realized aluminum is used as a conductor in lots of equipment).

Karl

 

Yeah, its tight and its bolted to a stock ground post. I found the stock ground strap on the front of the driver's side head and its a good connection. I'm going to put one on the passenger side head, too, and see what happens.