I'm cross posting this to general tech because I really need lots of eyes on this one. I drive a 1981 Bonneville wagon with the olds 307 motor. I need some help. We're just over halfway through a 10 day New England road trip, and yesterday I had my first issue with the car. My alternator belt broke. Thankfully, it happened when we were 3 miles from AutoZone, so I was able to pull in there and replace it. This is a brand new belt, not even a full week old. We've driven about 1600 miles and had no issues up to yesterday. After I replaced the water pump and all the belts, I did have some intermittent squealing when I first started the car, but it went away within a few minutes of driving, so I didn't bother checking anything. I felt like all the belts were slightly on the loose side, but nothing too far out of normal range At first I thought the alternator had failed, but when I parked and popped the hood, I saw the belt was off. When I looked at the belt, it was definitely broken, not melted. The alternator spun freely. After throwing on a new belt, I had them test the alternator, and the only thing that came up was a bad voltage regulator. I now do have much worse squealing, but I'm pretty sure it is from the alternator belt. Since the old one broke, I was concerned I had it too tight, so the new one is loose. So, I have four questions. 1. What would have caused that intermittent squeal on startup? Belts too loose? Belts too tight? (I don't think any gears are failing) 2. What could have caused that belt to break? 3. How bad is a bad voltage regulator? 4. Do I HAVE to replace the voltage regulator before continuing on the trip? I'm at a spot now that I could technically replace it, if any shop has the alternator in stock. I know the regulator didn't cause the belt to break. Would driving the car with the alternator not spinning cause the regulator to fail? If not, then I don't know how long it might have been since it failed, and I haven't had problems, so how serious is a faulty regulator? Thanks all!
No not spinning will not cause it to fail(alt) Very possible it was putting out enough juice to "get by" but not up to normal output so you did not notice. Do you have 1 belt or 2 on the alt and or PS? Olds engines are notorious for belt squeal. If I remember right they (or some) had a 2 groove pully on the PS and alt belt went on there too. You have to adjust/tighten the powersteering belt FIRST. Then do the alt belt. Always run belts for a good break in period then retighten them as they will loosen after break in.
What about the next time you start the engine cold? Does it squeal again for a few minutes and then stop? You had no squealing problems until after changing the waterpump and replacing all the belts. I wonder if you have an alignment problem. Nothing will tear up a belt quicker or cause a new one to fail quickly than having the pulleys misaligned. I would thinik it would be very bad. A malfunctioning voltage regulator can cause overcharging or undercharging of the battery and leave you stranded again. Ask yourself this: if the voltage regulator were not important, why would the manufacturer include one? This comment worries me, too. You seem to be of the mind that it's ok to leave the belt a little loose if there's any concern that it might break. Wrong. Don't leave it too loose. Don't make it too tight. Either of those can cause premature failure as well as pulley misalignment. Adjust the belt to the proper tension. It is not a difficult thing to do. One-half inch deflection at the mid-point between pulleys. I think people sometimes feel that when a belt is that tight, and it will feel tight when adjusted to that amount of deflection, that it's too tight. It's not. Of course you have to replace it if you don't want to be stranded again, this time with a dead battery or non-functioning headlights or who knows what. I can't believe you can't get an alternator quickly. I needed one for my '67 Delta 88, and the local Autozone had one in stock. Your car is much newer than mine. Did you ask the Autozone when they were testing your electrical system if they had one? Just for the heck of it, I checked my local Autzone online, and they have an alternator in stock for your car. I presume an Autozone (or O'Reilly's or NAPA or whatever) near you will have one as well. You're on a trip presumably many miles from home and away from anything familiar. You don't want to run the risk of another breakdown.
I have had an alternators fail a check at a parts store only to pass at a real auto electrical shop. A bad bearing can be a problem though. A voltage regulator either works or it doesn't. If it the car was running fine then it is probably good too. Has nothing to do with the broken belts. Most likely a tension or an alignment issue or both.
The squealing is caused by the PS pump belt. The 307 is very sensitive to proper belt adjustment and this is a common complaint. The PS pump MUST be tensioned using the proper method, which involves loosening all three fasteners (two bolts on the front under the pulley and a nut at the lower rear of the pump) then levering the pump using the pry points built into the bracket. Pulley removed for clarity in the photo below:
Recent symptoms experienced on a friend's '75 Mercury Cougar: pulsating headlights wipers operating at intermittent speeds (non-intermittent wipers) seems like there were a couple of other weird electrical issues too He fixed the problem by replacing his Voltage Regulator. On our '70s Fords, the voltage regulator is separate from the alternator. Yours might be integrated into the alternator. Good luck.
it is integrated you may also find even with new parts on a ford they will pulsate. On a ford you can NEVER have enough grounds off the battery 1 real good one to engine and I like 1 to frame and 1 to fender or rad support maybe 2. Or they can still pulsate. Fords and Chryslers always did with engine speed
Huge thank you to everyone! Based on all the comments, I went out today and double checked all the belts, and they were all a little on the loose side. After tightening them all up, the squealing is gone! As for the voltage regulator, I called the local AutoZone, and that alternator is special order, with two days to get it. They did give me the information for a local shop here in Hanover, N.H. that specializes is Alternator and Starter repair and work. I called them up and told them what was going on, and they said that based on what the car was doing, as well as how many volts my voltage gauge was showing, they couldn't see how the regulator could be bad. With everything I've seen and heard, it really looks like I just had a bad belt. Anyone else have a new belt fail like that?
Lamp pulsation on Fords (and some GMs) are caused by a bad diode or two. The regulator only turns charging on & off; the diodes change the AC power to a DC voltage level, along with clamping circuits. And I forgot about the dual P/S belt; I do, however, recall the option monster vehicles had a dual sheave ALT pulley on the larger alternators, but they're a bugger to find.
Tension it incorrectly or someone not putting all the accessories back together properly and causing a mismatch can cause the belt to fail. And sometimes things just go bad!
One other thing to check is the condition of the V-belt pulleys, I had a power steering pump pulley on a car that sat for years that had the bare metal surface were the belt rides corroded, it was actually acting like sand paper on the turning belt. I was having to readjust the belt tension every few days as the belt wore down. Then when it failed after a few weeks I inspected the inner surface of the pulleys and was shocked I did not notice its condition when installing the new belt. I also do not run cheap belts, I have found that they tend to squeal more than name brand belts such as gats ect.... They don't seem to break or wear out quicker, just irritate me.
A former boss of mine had a diesel GMC conversion van that had the same problem on the P/S pulley. I forgot about that; I'm trying to remember what I did to smooth the surfaces out. IIRC, I used crocus cloth glued to a stick to smooth them out, but I think it didn't work, as I do remember telling my boss that the pulley needed replacement as it was unrescuable.
You mentioned you replaced the water pump. There are 2 or 3 different length pumps. You may have gotten the wrong one. Check the pulley alignment.
