Help! 1998 Blazer Alternator Charging Problems
 

Alittle background: Problem started intermittently and it seemed like the car would stall and not restart, like the battery was drained, when making a turn. Then the compressor went bad and locked up and the belt broke. purchased a new belt to bypass the compressor, and had to replace the tensioner and the alternator. The battery would drain just sitting with the car off so I replaced the battery and tested for a short by putting an multimeter between the neg cable on the battery and pull each fuse to check for a short, None found. While driving the battery gauge would now show charging then after a stop and start gauge would drop from 13.5 - 14 volts down to 12.5, which to me mean't the alternator stopped charging. Pulled the alternator and took to an electrical shop to be tested and alternator tested good. Why is this car intermittently charging? Can anyone help?

Check your grounds.

Thank you for your response, right now the car is at my son in laws about three hours from me so I have to rely on him to check out the car for me. I know that there should be a fusible link somewhere under the Battery tray and there should be a ground strap on the back of the engine from the firewall, is there some other grounds I should be looking at? On the diagram below I am assuming it would be G106, G107, G108, but as to where they are he will have to trace them down I guess but any additional help would work:


https://blazerforum.com/forum/attach...ine=1412721271

Would a faulty fusible link under the battery tray cause alternator problem?

Before you tear things apart to check.

Grounds are easily functionally checked with a voltmeter from alternator case to battery ground during the malfuntion. If OK move on (OK is no voltage read)

Hot connections are easily funtionally checked with a voltmeter from hot terminal on alternator to battery + during the malfunction. If OK move on (OK is no voltage read)

I am betting that either your compressor delete belt does not have enough contact on the alternator pulley and starts slipping, or your new alternator is bad.

How many amps did it put out when it was checked? I bet whoever checked it did not put a load on it. This is the case when you get alternators checked off the car for free at Auto Aone, Advance Auto parts, O'Reileys, etc. Every shop used to have a battery load tester for on-car analysis, but sadly no one seems to have them anymore.

Good luck,

Les

Check the two contact connector on the backside of the alternator and follow the wiring back, checking for any damage. Also check the larger red wire connection, hopefully whomever installed the alternator did not over tighten this bolt and break the internal connection.

I'm with you about the belt. I'm having my son in law run through the checks. He did remove the alternator and took it to an auto electrical shop and it tested good ( I would imagine that they would have the means to put a load on it) They gave him a list of things to check so we will wait and see the result. Thank you for your input, these forums are great!!

That is a good thing to check, I will have my son in law check it out. Thank you for your input. I will post an update soon.