oes whistle-sound indicate alternator issues (1988 3.2)?
08-09-2016, 03:16 PM
#1
Instructor
Thread Starter
oes whistle-sound indicate alternator issues (1988 3.2)?
I have owned my '88 Cab for over a year now with 148 Kmiles, but it is my first air-cooled so I don't have experience with sounds - which are normal and which are not.
The car has always had a whirring, whistling sound from the back and I always assumed it was the cooling fan. The audio frequency of the whistle tracks with RPM.
But recently I noticed that when I turn on the headlights, the sound gets much louder. Also, the whistle appears in the right speaker of my after-market stereo - especially when the headlights are on.
So now I am wondering if this indicates a possible problem with the alternator, maybe a bad diode on the regulator or something and I am now worried that the alternator may soon fail.
I have most, but not all service records and I did not find any record that the alternator has been changed. The alternator "looked" new (cleaner than other stuff) when I got the car.
Should I replace the alternator to prevent a failure?
The car has always had a whirring, whistling sound from the back and I always assumed it was the cooling fan. The audio frequency of the whistle tracks with RPM.
But recently I noticed that when I turn on the headlights, the sound gets much louder. Also, the whistle appears in the right speaker of my after-market stereo - especially when the headlights are on.
So now I am wondering if this indicates a possible problem with the alternator, maybe a bad diode on the regulator or something and I am now worried that the alternator may soon fail.
I have most, but not all service records and I did not find any record that the alternator has been changed. The alternator "looked" new (cleaner than other stuff) when I got the car.
Should I replace the alternator to prevent a failure?
08-10-2016, 03:38 PM
#2
Team Owner
I wouldn't . But I would keep my eyes out for a deal .. I bought one at Hershey as I had the same concern you did , a whistling sound . its been sitting on my shelf for about 8 years now and hasn't moved an inch.
I would see what kind of voltage you are seeing at your battery while idling and at 2,000 rpm . I don't remember the specs but if you are getting 13.5 -14 v I would leave it its fine. Go fix the ground on your crappy aftermarket radio
I would see what kind of voltage you are seeing at your battery while idling and at 2,000 rpm . I don't remember the specs but if you are getting 13.5 -14 v I would leave it its fine. Go fix the ground on your crappy aftermarket radio
08-11-2016, 10:34 PM
#3
Instructor
Thread Starter
I wouldn't . But I would keep my eyes out for a deal .. I bought one at Hershey as I had the same concern you did , a whistling sound . its been sitting on my shelf for about 8 years now and hasn't moved an inch.
I would see what kind of voltage you are seeing at your battery while idling and at 2,000 rpm . I don't remember the specs but if you are getting 13.5 -14 v I would leave it its fine. Go fix the ground on your crappy aftermarket radio
I would see what kind of voltage you are seeing at your battery while idling and at 2,000 rpm . I don't remember the specs but if you are getting 13.5 -14 v I would leave it its fine. Go fix the ground on your crappy aftermarket radio
The after market stereo is a high-end Alpine from the mid-90s (installed by a prior owner) with awesome sound (else if I would have gotten rid of it). But the hum is in the right channel only even when I reverse the inputs from the head unit left to right, the hum stays in the right channel only. So I do suspect a bad ground internal to the power amp. Sometimes I hear the identical subject alternator whine reproduced in the right speaker.
But I wanted to run down the alternator thing because a bad regulator might put more noise on the DC power lines in the car - not sure why that would only show in the right channel. Next step is to pull the amp and see if it can be fixed.
Thanks for the response.