GM sidepost battery questions

[Breadfan]

I am working on a general motors vehicle this weekend with a sidepost terminal battery. These corrosion resistant connections tend to just corrode in less visible place.

I'm getting a new battery, and trimming the cables a few inches to get some clean copper. From what I recall the cables run in some conduit that makes changing them hard so I may just trim the cables rather than replace them this time around.

I am thinking of convertring to top post mount.

Has anyone done this and is there any issue with doing it? I know I can buy a battery with both side and top posts so all I'll need to do is trim the cables and add top post terminal connectors.

Will this work?

Vehicle is a '95 Chevy suburban.

It had an issue that is warranting this work. I was test driving it for a few weeks and it ran fine but one night I was leaving a parking spot - I started it up, put it in gear, and starting going.

I moved 3 ft and the entire electrical system went dead. The car died, and there were absolutely not lights or any electrical at all.

I got out and pulled on one of hte sidepost connectors and everything came back.

I am afraid to drive this car at night now if I were to hit a bump and short it out like that again I would lose all functions including lights - on a dark road that could be seriously dangerous.

Since the battery is a few years old it's going to be replaced for safety's sake, and the cables will be trimmed as mentioned to good copper. I believe they were replaced once before so I don't think I'll need to replace the entire cable.

Anyway, I've never had a car go that dead due to a bad connection. It could also be a short inside the battery, I have had that.

So in summary will the top post conversion be Ok to do and how does my game plan sound?

[magindat]

I've had the entire post come loose from the grid inside the battery due to corrosion. Side post suck.

Your only issue will be making sure that when you slam the hood, nothing will touch the posts. This may mean lowering the battery. Also, make sure you have a very sturdy battery pan and hold down. In a truck with stiff suspension, the battery will 'jump' and short if not strapped down.

Otherwise, your ideas are sound.

Of note, if you measure your pan and height you are very likely to be able to fit a much larger (CA and CCA) and stronger battery in the space.

[Breadfan]

Cool, thanks for the info! I will check the hood clearance before hitting the store, I believe there is plenty, and the battery pan is pretty big so I may try to max out my CCA. I will take measurements before hitting the store.

My only other concern would be if the calbes are trimmed is there enough slack to move to top mount, I also don't think this is an issue but I'll add that to my list of checks before hitting the parts store. :)

[finster101]

I would highly recomend replacing the cables. Here at the Cadillac shop we see a ton of drivability problems related to voltage and crappy connections.

[Paul T. Casey]

Clearence is the only worry I can think of, did the top mount conversion on a few myself with no problems. I'd check the other ends of both the hot and ground while you're at it since it came back when you pulled on cable. I've had gounds come off at the engine, bolts loosen up especially in an older potentially oiler car.

[Breadfan]

I would highly recomend replacing the cables. Here at the Cadillac shop we see a ton of drivability problems related to voltage and crappy connections.

I will atleast cut any corroded areas from the ends of each cable, and re-termianl on good copper. My experience is that the corrosion only affects the end unless the cable is really old.

I will inspect each cable and test resistance after trimming them, if they look good and test good I think they'll be OK for now.

I seem to recall the cable running through a conduit or being tough to remove, it's been done once, if it's easy I'll just do the cable but otherwise I think I'll jsut trim it, test it and inspect it. Would this be sufficient if the cables check out?

Thanks!

[Richy04]

That should have ran without the battery unless you had lots of accessories on. If the problem continues here are some areas on GM vehicles to look at.

1. The terminals/cables and battery itself (problem can be inside the battery as well). There is sometimes an accessory positive that needs a fresh connection at the positive terminal and there is one sometimes right off of the negative which runs to the fender mount while the other side of the negative attaches to the engine block or alt mount.

2. Check all groundstraps, they usually come off of the valve covers on GM vehicles and attach to the firewall.

3. Check the connector going into the alternator itself, also check down by the starter, there is a fusible link in the starter harness that goes bad there as well and this will cause the whole vehicle to lose everything.

[Breadfan]

Thanks I'll check all these areas. Thanks for reminding me about the link I know we replaced that once due to some issues so I will probably put a new on it - cheap insurance.

[GreekGod]

We have a 4x4 Chevy truck at work that had accessory connections added to the side terminals (snow plow, etc.). They were always loosening up, until the side term. threads were worn so bad, they wouldn't hold their torque, even when they felt tight.

I talked with an old-timer that works for a big excavation company. He said their (frequently) off-road, 4x4 Chevrolet pickups had the same problem. Rough roads, like we drive on where I work, seem to lead to side term. connection failures.

[Aren Jay]

No help for you here, but I was with a friend in his old Ford Escort in England and the battery posts were so corroded that when we tried to jump his car to start it the posts turned to powder and dissappeared. We ended up towing it back to the college.