beachbum Posted June 23, 2004 Share Posted June 23, 2004 i read all the gm alternator swap stories,and wanted to know is there any higher output amp that will just bolt on to a ea81? cause my amp gauge always read just a little over half (about 13 or 14 volts)and i just got my a/c done yesterday and noticed that it was pulling the gauge down to about 8 volts normal? thnx Link to comment Share on other sites More sharing options...
canajun2eh Posted June 24, 2004 Share Posted June 24, 2004 14 volts is normal for your alternator. The A/C doesn't use any appreciable amount of electricity. I'd venture to suggest that the alternator drive belt needs tightening. Since the A/C compressor is driven off the same belt, and since the A/C uses quite a bit of engine power, it would stand to reason that the drive belt is slipping. Link to comment Share on other sites More sharing options...
beachbum Posted June 24, 2004 Author Share Posted June 24, 2004 hey guy ur post is very informative but i have a belt for each the alt and the a/c and they r both tight,any other ideas to check? thnx Link to comment Share on other sites More sharing options...
WoodsWagon Posted June 24, 2004 Share Posted June 24, 2004 Check the electric fan to make sure it isn't jammed. It comes on automatically with the A/C, so this is the only high load thing I can think of. Link to comment Share on other sites More sharing options...
beachbum Posted June 24, 2004 Author Share Posted June 24, 2004 as u probably already know i have 2 fans,1 i got set to come on with the key,and the other comes on when the temp rises,but anyway they r both working fine,anymore ideas? Link to comment Share on other sites More sharing options...
Scoobywagon Posted June 24, 2004 Share Posted June 24, 2004 Just so I'm clear... You normally show 13-14 volts until you turn on the a/c at which point it shows ~8 volts. Right? If that is the case, then there really isn't much for it. 14 volts is appropriate for ANY alternator in a running car. Much higher than that and you risk burning things up (like computers or VRMs...you know...stuff like that). An alternator with higher output MIGHT solve your problem, but it would introduce others down the line. How old is your battery? What is its reserve power rating (usually shown in minutes)? Take the car to a GOOD parts store (by which I mean NOT Sucks...er...Schuck's or any of the CSK stores). Have both the battery and the alternator tested. I suspect that you have a dying battery. If so, replace the battery. I'll bet dollars to Krispy Kremes that this will decrease the problem, though I sort of doubt that it will go away entirely with just a new battery. I'd also crawl up under the dash and hook an ammeter into the power for the squrrely cage fan that actually blows the cold air around. See how much power it is actually pulling. I can't remember what it is supposed to be, but I think it is somewhere around 15 amps at high speed. Just remember that 15 amps is fully a third of the stock alternator's nominal output, so you are GOING to see some drop in voltage with the A/C blowing. Oh, and if it should turn out that the alt is going south on you, spend the extra bucks to get a replacement VRM while you're at it. Link to comment Share on other sites More sharing options...
beachbum Posted June 24, 2004 Author Share Posted June 24, 2004 ok ill go to the auto parts store tomarrow,down here a good 1 for that stuff is autozone, now vrm? im assuming that is something to do with the voltage regulator?and if so i thought that was incorporated into the alternator?let me know cause as with all areas im learning from u guys. thnx bb Link to comment Share on other sites More sharing options...
aba4430 Posted June 24, 2004 Share Posted June 24, 2004 Beachbum, When you turn the AC on, does your rpm drop low? If so, and depending on how low, you might not have another issue to deal with. With the rpm's low, your voltmeter will bog down. I have the same problem with my 87 Brat. I need to get hold of the dealer installed AC technical details (Does anyone have this?) to see how to fix the idle up adjustment that is linked with the AC system. The system includes the vacuum switch on the passenger strut tower with two hoses, one from the firewall (via a t-connector) and one hose connecting to a diaphragm gizmo connected to the carb. See if this is your problem. As others have suggested, the starting/charging system should also be checked, just in case. Regards, aba4430 Link to comment Share on other sites More sharing options...
mcbrat Posted June 24, 2004 Share Posted June 24, 2004 you can find direct bolt ins, but they are costly. I was lucky, and found a streetwires 135 amp alt that was on eBay.... I have done searches on high powered alts, but they are usually 300-600 range!!!! a remanned XT6 alt is like $150.... Link to comment Share on other sites More sharing options...
beachbum Posted June 25, 2004 Author Share Posted June 25, 2004 thnx mcbrat and aba,when u find that diagram let me know cause i raised my idle manually today and it was alot better,but i did also notice that thing u were talking about on the passengers side and apparently its not working cause my idle doesnt go up when i turn on the a/c, so let me know ok? thnx bb Link to comment Share on other sites More sharing options...
Scoobywagon Posted June 25, 2004 Share Posted June 25, 2004 Beachbum, Sorry, VRM = Voltage Regulator Module. Some appear to be internally regulated, while others are not. My 81 has an external regulator (silver box mounted to the fender above the passenger wheel well just behind the battery) while my 83 does not. At least, I've not yet identified anything that looks like a vrm... Link to comment Share on other sites More sharing options...
beachbum Posted June 25, 2004 Author Share Posted June 25, 2004 thnx scoob, i thought that was what u meant just making sure,mine is internal, Link to comment Share on other sites More sharing options...
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