Lately I've had an issue with a fan belt squeek... almost all the time. Been going on for a long time actually, and I just keep replacing and tightening the fan belt. Annoying.

Yesterday on my way to town, I heard an odd 'gong' noise... sorta like something hitting the underside of the hood. Didn't seem to cause any problems or happen again, so I sorta forgot about it.

THis morning, It was rather cold... below zero. So in order to avoid breaking the key off in the ignition, I started the car with a jumper wire at the solenoid. While I was under there, I found the source of the 'gong' noise... seems one of the covers had blown off the battery.

Putting two and two together to get five, I'm figuring that my battery must be getting overcharged and boiling, which would account for both a squeeky fan belt, and the battery almost exploding. Does that sound like a likely diagnosis? Could it be in the wiring, or the battery itself, or most likely just a bad alternator/regulator?

Car in question a '66 wagon with a delco alternator conversion. Only part I find odd is it seems to me if it were overcharging, the amp light would be on... and it behaves perfectly normally.

Thanks for any thoughts...

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-Matt '70 145s, '65 1800s, '66 122s wagon, others inc. '53 XK120 FHC

I had the same problem with a noisy fan belt on my 122S of 1970 vintage. Try spraying a small puff of aerosol silicon spray lubricant on the belt while the motor is running. It certainly solved my problem.

Greig;

That may have stopped the squeal, but it did this by letting the belt slip without vibrating (creating the squeal)...silicon spray, after all is a lubricant...the point of a belt is to transfer rotational energy, and it can only do this if it has FRICTION with the pulleys!

I recommend againt your advice. If the electrical components are OK (no high load), a squealing belt wants to be tightened a little more (or have its contact surface roughed up with some emery cloth to INCREASE friction), not lubed!

And if you don't want to get you hands dirty adjusting the belt, and figure you can fix it by just spraying some magic on it, from out of a can, try "belt dressing"!

Cheers

Ron, many years ago I worked as a farmhand, and we had a big combine that was all driven by big belts. Sometimes there was enough load that one belt or another would slip, quite visibly... and the cure was to apply castor oil to that belt.

Makes no sense to me at all and certainly doesn't pertain to the problem this thread is about, but it really did work.

Phil;

I believe you...farmers often come up with interesting solutions...but I still say that lubing a belt cant do any good...but since oil is known to attack rubber, probably what was in fact happening was the oil was attacking the surface more than lubing it (I'm sure it got tossed off shortly anyway), changing its coefficient of friction with the pulley and curing the squeal...that's the only explanation I can think of...

Cheers

As Ron and Phil mentioned, I really should have put a volt meter to the thing before I posted.. Wouldn't have had to post the problem here at all.

I think my suspicions are correct though... put a meter on it this morning. voltage at the cigarette lighter coming in at about 17.8v even at idle. Way high. Comes down to a slightly more respectable 14+v with the lights and heater fan on, so thats how I'll drive today. Will put in my spare alternator this afternoon.

This is a new one for me.. Thanks again for all y'alls insights.


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-Matt '70 145s, '65 1800s, '66 122s wagon, others inc. '53 XK120 FHC

Matt;

If that doesn't help, I suspect an open cell in the battery (which doesn't clamp the system voltage and allows it to soar - but this is unlikely if the battery is putting out good starting current, a load test of bat will confirm this), or a high resistance in serires with the battery (which will allow the voltage to soar also).

In troubleshooting its alway most informative to change ONE thing at a time...that way when it works as expected you know exactly what cured the problem...so if changing the alt doesn't help, clean and tighten all main power connections after applying anti-corrosive zinc paste.

When the system voltage is that high, you might want to refrain from using the radio, whose components may not be quite as forgiving of overvoltages...light loads will run bright as hell at the expense of a shorter overall life (twice a bright for half as long etc.)...

Good Hunting!

Okay, I don't live in a cold climate where I have to worry about breaking my key off in the ignition, but I have hear stories where the battery gets almost frozen, but still has enough power stored to start the engine and once the engine starts chargin normally, the battery qucikly heats up in the places that aren't frozen and explodes... it sounds like this is what is happening to you. Two options if this is the case - 1. Buy a Starved Lead Acid battery (Exide Orbital is a good example) 2. Get a battery heater and plug your car in at night to keep stuff from freezing.

To rule out the alternator, hook up a voltmeter to the car while it is running - you should get a voltage no less than 13.3 and no more than around 15.

Good luck!!

-Flup

More likely the battery has a partially shorted cell.

makes sence... good thought.

But, wouldn't that cause it to be weak? It does start up fine on these frigid mornings. I'll swap batteries though and see if it helps.

Thanks!
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-Matt '70 145s, '65 1800s, '66 122s wagon, others inc. '53 XK120 FHC

Nope... battery swap made no difference... rats. That woulda made it easy..
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-Matt '70 145s, '65 1800s, '66 122s wagon, others inc. '53 XK120 FHC

Sorry, it was just a thought.

What voltage do you get across the battery terminals with the engine at idle, and also at higher rpm? I should actually have suggested that as the first step in troubleshooting it.

Guys;

...if lights are bright, wiper/blower motors running fast, that suggests an elevated system voltage, but without system voltage and/or battery current data, either of which requires some instrumentation to be connected, it's really all just uninformed conjecture! Alternator may be overcharging battery with a regulator failure which includes a bad ground to the regulator either external or internal to the alt.

A squeeky fanbelt not only means its loose...it can also mean that there is a high load on the alt..this makes the alt more difficult to turn and causes the belt to slip and squeek...

Also, an overcharging system will NOT light the AMP light...that only lights if output of alt is low, not high...again, an AMP meter would tell a lot more...

Good Hunting

Also, an overcharging system will NOT light the AMP light...that only lights if output of alt is low, not high...

Ron, for once I must disagree. About six weeks ago I noticed the amp light on my 1800 glowing dimly at cruise and getting brighter with increasing RPM. I measured the battery going over 16V by 3000 and climbing. Turned out to be a bad connection in the DF circuit internal to the alternator (Bosch 55A).

Right now I have a customer car here with a dim, but uniform, glow... it's also putting a bit over 16V across the battery (SEV, haven't troubleshot it yet).

So yes, overvoltage will bring on the warning light.

Phil;

So my posts aren't long enough...you want I should explain all the exceptions...;-)

...you had the unusual exception case there...and the explanation is that the AMP light lights when it sees a difference in the voltage at the battery and output from the gen/alt...normaly and typically this is caused when the gen fails to have an output, but it can certainly also happen, as in your case, when the difference is the other way around...with the gen/alt output way more than the poor battery at 13 or so volts...

You are absolutely correct!...boy, I bet the headlights were nice and white!!!

Cheers!

Thanks Ron..
I know I shoulda done some basic checks... but I posted at work, and all my meter stuffs are at home. I'll take some measurements. I'm sure it will be easy to tell if its overcharging.

And... on your amp light comment. Based on that, I'll take back what I said in a previous post about adding a volt or amp meter on the 1800 lists a while ago :-)

Cheers
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-Matt '70 145s, '65 1800s, '66 122s wagon, others inc. '53 XK120 FHC