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73-87 Chevy _ GMC Trucks => Electrical => Topic started by: 87 Wrangler on August 15, 2015, 06:12:11 pm
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A while back I posted about my charging issues, and thought I had it all fixed. Wrong! Iv cleaned my grounds, ended up changing the alternator and battery. Also repairied a corroded fusible link wire and checked others for corrosion or issues. I don't know what to do now.... My alternator is now noisy like the last one, especially when I turn on the fan lights and wipers. It drops to 14.1 or so at idle full loaded, and 14.3 all the stuff off. Seems to work ok but it's noisy!
Since all the repairs my gauge would bounce around a bit then always go back to 14.3v or so while driving. Then yesterday in the rain it dropped to 12.5 and it started "moaning", I found the belt slipping and changed it out. Worked fine the rest of the day till it started moaning again unloaded. I investigated today and found my power steering pump siezing up so I swapped one off my parts truck, thinking it was robbing power and causing the moaning. But after everything it's still noisy fully loaded, not so bad unloaded but you can hear sonething not right.
Sorry for being long winded! Just like to give all the info possible, this has me stumped!
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So you aren't having charging problems, you are having noise problems? Sorry but I got a little lost, is the power steering box fixed?
Belts lined up? You don't have it too tight do you?
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Is the noise a squeal or a whine? Alternators under high load sing with an electromagnetic whine.
Recheck the belt tension. With the engine off, grab the alternator fan with your hand and try as hard as you can to spin the pulley. If you can rotate the pulley at all, the belt is too loose.
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Sorry for the info overload!!
Yes i changed the power steering pump and it works well now. I changed the serpintine belt after i noticed it slipping, which caused my voltage to drop initally. Now it stays up over 14v idling or driving consistantly. Before it would "churp" the belt when i started the truck, now after the new belt and pump it seems fine. The alternator does "groan" tho, unloaded not too bad, but with accessories on it is very noticable. When i unplug the 2 pin connector on the top, the noise goes away. Then i re connect and it is loud...then gets quieter.
I did tighten the belt up pretty good so it is prob too tight now, and i will check the alternator, if everythng spins ok and lined up properly.
Another thing iv noticed, not sure if its related- My volt gauge randomly seems to stick in position, if i smack the dash somtimes it will increase or decrease slightly. Also the speedo needle was bouncing slightly at the same time. I think i have gremlins....
Thanks for the input guys i really appreciate any help.
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- The speedometer is cable driven, so the "bouncy needle" is probably a dry cable and/or slightly bent cable housing. Greasing the cable is easy enough to do and should solve the problem.
- The voltmeter needle sticking might be the gauge or its connections to the printed circuit board. Also, double check the instrument cluster ground to the PC board and cab sheetmetal.
- The initial chirp from the belt when started is an indication of excessive belt load or a loose drive belt. The belt chirps as it out-accelerates the pulley. Check the belt tension using the method I posted previously. Also, make sure the noise is not originating from the A/C compressor belt.
- Collectively, the 'chirp' and 'groan' that you've described suggest a consistently high electrical demand on the charging system. If belt adjustment doesn't correct the issue, you should have the system professionally tested - the battery load tested, alternator current output measured, and the system wiring verified. Alternators will not generate maximum output indefinitely without incurring internal damage. Make sure there's not an underlying problem or the alternator and battery may overheat.