I know this has to be bad.....

[Black Sun 5.0]

Brand new battery, engine, the whole biz. Well I noticed my electric fan and DC Control unit, which was working fine, started to act flaky. I open the hood and noticed a white substance on the terminals of the battery. Obviously there is a problem. What would cause this?

 

[87'GTstang]

Brand new battery, engine, the whole biz. Well I noticed my electric fan and DC Control unit, which was working fine, started to act flaky. I open the hood and noticed a white substance on the terminals of the battery. Obviously there is a problem. What would cause this?

pasty or poweder-like?

 

[Black Sun 5.0]

I would have to say pasty.....

 

[cobradvm]

Its battery acid corrosion - a simple mild alkali will clean it off like baking soda or a coke for that matter. You can apply petroleum jelly after cleaning the posts to prevent it from recurring.

 

[GT Drifter]

and use some steal wool or sand paper on the posts too.

 

[baskin]

If you're all of the sudden getting a lot of paste on the battery, then it's boiling off one or more of the cells. Either the battery is bad or the alternator is overcharging. Some of the cheap batteries are bad out of the box or last only a couple of mos.

I'd pull it and get it checked. If the resistance gets high enough on the terminals or a cell opens, the alternator can output large spikes in voltage, particularly when a heavy load is removed from the system. It's pretty hard on the controller since it will attempt to provide the filtering that the battery normally provides. You could also get real unlucky and have the alternator take out the injector drvers, since they're not protected.

You definitely don't want to disconnect the battery in order to see if the alternator is charging, it's a bad idea.

 

[Black Sun 5.0]

It's a Firehawk battery I think. The shop that installed it told me that it's normal corrosion and that it may have caused my fusible link for the DC Control unit to go because of the poor connection it caused. Sound right to anyone? He sounded pretty knowledgable on the issue, but I find it odd that a 3-4 week old battery is corroding so fast. I've never seen this happen before. They recommended cleaning it and replacing the link. Also, what would cause the alt to overcharge? I had electrical issues with the car before, but the culprit was repaired. Could the voltage regulator in the alt be toast?

 

[Black Sun 5.0]

bump

 

[baskin]

I find it real odd. Did they check the battery. If it has a bad cell, it will continously boil off the sulfuric acid from that cell. Were any of them low?

As far as the alternator overcharging, one reason would be a bad diode bridge. If the bridge is bad, it will actually undercharge slightly at idle, but what happens is that as the armature passes the set of windings that's connected to the bad set of diodes, the regulator will turn full on in an attempt to generate more voltage. When the next set of windings hit, the field is saturated, so you end up with a voltage spike.

A bad regulator would also cause the problem, but it would most likely be shorted and the voltage would be high enough that you would have probably noticed it.

The regulator is easy to check, 14.4 - 14.6 V @ 2000 rpm, the diode bridge can be checked by measuring the AC voltage at the alternator. I'm not positive on the spec, but I would think that it should be less than .2V.

Another possibility is that the battery is draining overnight. If that's the case, the alternator will charge the battery at a high rate and boil off some of the acid. The battery should be at about 12.6 after sitting overnight.

 

[Black Sun 5.0]

Just to fill in on the situation, the battery appears to be fine so far. No issues starting in the A.M. Not that it means the battery is 100%. At idle, there are no sudden dips on my volt gauge. When I start the car cold, the stock Ford gauge reads just a bit above the midway point, not quite to the next line on the gauge. After driving for a bit, the gauge dips down to about center of the gauge, sometimes just a bit below. I've been told that this is normal once the car is warmed up and the battery is fully charged. Last night, I cleaned up the terminals and cables that had corrosion on them and also coated the terminals with some corrosion protector. If it happens again, I'll know that the shop was wrong and there is another issue. What about a short somewhere in the system? Could this be an issue? Also, I may have an issue with the fusible link for my DC Control, I'll find out in stop and go traffic tonight. By the way, does anyone here know what size fusible link I'd replace it with if it is an issue? I don't know what gauge the link is that came with the DC Control.