Voltage regulator,alternator, or radio

[rekstein]

History of problem. Was driving along one day this summer in a 1988 911 cab and heard a squeal every now and then from the engine very infrequently. Had an old Alpine radio that I wanted to upgrade to satellite and blue tooth capable. Had a new Kenwood radio put in as I decided to treat myself and not crawl under the dash. Old amp was removed and so were the woofers. I get the car back and the new radio intermittently loses power. Bad connection, right? Then I notice the lights also dim at night by themselves and power goes out to the radio as well sometimes.
Also at this time the squealing gets louder intermittently as well. Replaced the belt with factory belt but its so tight I can only use 3 spacers. Things seem to be better less squealing, and less power loss cycling of the radio.

I investigated and find the radio is hooked up to the wrong circuit. Car is taken back to the shop and have that corrected. Go to Autozone and get new knock off belt as squeal is still present. This is the belt the same belt that was on successfully for the last 30 k miles. Literally, have to cut to cut the OE belt to get it off. Leave Ac belt off as well to rule that issue out. Replace the fan belt with Autozone belt, 5 spacers outside and one inside. seems reasonably within tightness limits

Today on 60 mile trip no squealing 95 per cent of time. Radio no problems. No intermittent power loss. However one or two times there was a squeal with or without power-loss but nowhere near the level before.

So is it the voltage regulator,alternator,and or the radio? does Autozone diagnose this issue as I have read.

I would appreciate the groups thoughts as well as recommendation if I have to have the ball bearings rebuilt which I understand is a problem and who is recommended

Thanks to all

[mrdieseldude]

Intermittent problems can be tuff to diagnose... not a job for the Autozone group. Start with knowing what your voltage is; at all times. With the engine on, you should be upper 13 ish. With a lot of load (headlamps, radio, etc.) it will/may drop some. You will need an accurate and digital voltmeter. They make these cheap now that will plug into your cig lighter. Monitor this for a while and see if you can correlate the squeals to the volts. That is where I would start.

Michael

[jpnovak]

Loose or worn alternator/fan belt. Squeal is the belt slipping. Check for worn alternator bearings causing fan to slip down reducing tension. Also look for cracked alternator/fan housing doing the same thing.

Scrape marks on the sides of the fan and housing are tell tale signs.

[T77911S]

take it to autozone and let them test the system, its free.

could be the bearings going bad as mentioned, but they usually have a dry sometimes grinding sound when they are bad, but i was leanig towards them causing resistance and making the fan hard to turn, but i doubt it.

you had to cut the belt off???