18 volts at the battery (again)!!!!

[kxnomore]

I had this problem a while back and changed over to the internal regulator kit. Everything was good for a while, but this morning it's happening again.

Everything connection wise checks out okay, but it is applying full amperage to the battery at all times. Even disconnecting the plug on the top of the alternator doesn't make any difference. Neither does undoing the jumper wires at the old regulator connection. If the truck is running the amp gage is pegged all the way to the right.

So it's done this with both types of alternators, and with all new charging system parts.

Anybody have any ideas? Harness problems maybe???

[89 crew]

Have you checked with a different gauge? If it isn't a bad gauge then it has to be either a damaged regulator, or the wire connecting to the regulator back to battery check it for resistance.

[8696steve]

I you are not running a single wire alt, then I would suggest that the two wire are backwards. If the truck sits for a while and the battery goes dead it is definitely the two wires one to the regulator and one to the ignion switch that are criss crossed.

[70' GMC]

I thought it was 12 volts for the battery, I think that would be good then have amps added into the truck.

[Sweet72]

Your ammeter indicates the load that is on the system. A short is seen as a "load" by the ammeter and will peg or at least cause it to indicate a high current draw. I'd start by pulling and reinstalling the fuses one at a time and watch the ammeter. A fuse will blow if it's rated current is exceeded. It may be an "unfused" circuit. There may be a chaffed wire somewhere that's causing an intermittent short to ground. Inspect your wiring and fuse block. I don't think it's your alternator install. Ever heard the story of the guy who replaced a blown fuse in his jeep with a .22 long rifle shell?

[truckdude239]

first time to check is the gage a bad gage will cause this problem seeing that the gage tells the voltage reg what to do. if u undid the jumper down at the external reg then u unhooked gage from the new reg so that should leave the gage out(ie mean the gage isn't the problem. i'd pull the alternator and take it to a parts house and have it tested just o make sure u didn't get a bad one

[Sweet72]

When did the ammeter start tellin' the voltage reg what to do? Bossy little gauge...

[72BLUZ]

sound like the voltage regulator took a dump!!

[truckdude239]

the volt meeter or idiot light lets the volteage reg what to do heres is some tips

[kxnomore]

Originally Posted by Sweet72

Your ammeter indicates the load that is on the system. A short is seen as a "load" by the ammeter and will peg or at least cause it to indicate a high current draw. I'd start by pulling and reinstalling the fuses one at a time and watch the ammeter. A fuse will blow if it's rated current is exceeded. It may be an "unfused" circuit. There may be a chaffed wire somewhere that's causing an intermittent short to ground. Inspect your wiring and fuse block. I don't think it's your alternator install. Ever heard the story of the guy who replaced a blown fuse in his jeep with a .22 long rifle shell?

That's probably it. I did take the alternator back and their tester was broken, so they gave me a new one free, which is cool.

So now the battery is reading 14.5 volts while running, but the ammeter gage is still showing a high charge rate. The battery is also bubbling a bit still. It reads about 13.2 volts sitting, so it still is getting overcharged, I think. All the fuses are good, nothing blown.

I'll go out tonight and disconnect the heater wiring, as that looked jury rigged from the PO. The heater is working just fine, though. So if it's a short that's causing a high load, can that tracked down with an ammeter? Could I check the amps with the key turned on but not running? Is that just putting an amp meter between the negative terminal (disconnected) and the battery? and turn the key and see what happens?