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Friend bought a 1992 240 ~200K miles. Had been sitting ~ 1.5 years; PO said that a mechanic said “something might be wrong with the alternator”
1. The belts squealed. I replaced with matching used Volvo belts and replaced the brushes - the old ones were OK, not great. Alignment was fine, bushings tight. Squeal continued: at high idle, under acceleration.
2. Replaced the alternator pulley and replaced the belts with new. Seemed better for a while, then squeal started again.
3. Replaced the alternator and battery. Still squeals.
4. 3rd alternator, still squeals. It quits after 10 minutes of driving.
It's not the damper or the a sticking water pump. Belts are tight and not frayed. Nothing is rubbing. Alternator bushings are new and alignment is true.
Could be that I have the wrong belts and they aren't making good contact. Or a wrong pulley on the water pump. Otherwise I've no idea.
One odd thing: was driving the car (between items 2 & 3 above. The squeal quit and the instrument warning lights came on. Limped home. Brushes were fine.
Excite wire tested for ground but between the grey firewall connector and the dash (with the plug removed from the cluster), not between the connector and alternator - this is a 1st for me. I also had continuity both ways. I replaced the wire between the connector and the cluster and the instrument lights went out.
It's possible that alternator #2 failed internally and somehow fried the wire.
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240 drivers / parts cars - JH, Ohio
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Check the crank pulley, the outer ring can spin in relation to the inner ring. Buy a silver sharpie and draw a line across all three sections of the pulley at the front, the pulley has a rubber section sandwiched between the inner and outer rings. Drive the car then check the line and see if they have moved.
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Bruce S. near D.C.
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Yes, did that. I should have been clearer when I said that the damper was fine. I keep a bottle of white touch-up paint and paint a line on most cars I work on.
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240 drivers / parts cars - JH, Ohio
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"Excite wire tested for ground but between the grey firewall connector and the dash..."
Huh? Can you explain "tested for ground?" How exactly. Spare no details. Don't assume any testing method to be "common knowledge."
Anyway, nothing you could do with the D+ terminal would make the alternator belt squeal, except as it would squeal for the usual reasons when the expected load occurred.
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Art Benstein near Baltimore
I find it hard to believe there are actually people who get in the shower first and THEN turn on the water.
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Take a simple 12V voltage test light, hook the alligator clip to the positive battery clamp, touch the probe to the negative battery post, the bulb goes on. Touch the engine block, bulb on; touch 12V positive, nothing. I touched the excite wire, disconnected from the connector and the instrument cluster: blub on.
Or am I missing your point?
AB: "Anyway, nothing you could do with the D+ terminal would make the alternator belt squeal, except as it would squeal for the usual reasons when the expected load occurred."
I agree. I mentioned the excite wire failure as it's a data point and because I'd not seen one fail between the connector and cluster.
I drove the car this evening. The belt now only squeals for ~ 10 seconds after startup - which is not unreasonable.
I'm going to remove the alternator belts tomorrow and inspect. I wonder if either they are for an earlier 240 with a narrower V or one was on the shelf for a long time but the other is fresh.
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240 drivers / parts cars - JH, Ohio
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This problem can affect 240's everywhere! Have a read of this thread. The meat is on the last page but start from page 1. I'm in there a couple of times.
http://www.volvoforums.org.uk/showthread.php?t=115232&highlight=240+belts&page=3
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Thanks Derek, good thread. If I understand it: there are 2 common belt widths for 240s - 9.5mm and 10mm; but a Volvo tech said that Volvo only used the 9.5s.
I'm going to drive the car some today to see if it continues to improve. Then I'll inspect/ clean the 3 pulleys again and perhaps swap to wider belts - I saw a set looking through my spares. A few observations:
1. I have several spare alternators. Visually, the alternator pulleys from the older (83-85) cars look like they are tighter ie. the pulleys are made of thicker metal and seem less deep.
2. When I installed the 3rd alternator (one from an early car), I had more trouble getting the belts over the pulley. That could mean that the housing is larger and won't move as close to the motor.
2a. Visually the belts don't seem as far down into the pulley; and
2b. The adjustment screw did not require as much tightening.
3. Folks say that there are standard sizes of alternator pulleys. Maybe there's a a US one that's close to metric (angle) and these get swapped around on the rebuild assembly line. So perhaps the 9.5mm belts only work well in a clean and correct pulley.
3a. There are BTW at least 2 water-pump pulleys - 2 different center hole sizes.
I'm going to infer from all this that I happen to have a mismatch of belts and pulleys. The water-pump and crank pulleys look good but I'll recheck.
I've had similar problems with other 240s (albeit not quite this bad) that were fixed by swapping belts and pulleys.
OTOH, my 240 driver a few years ago had been parked in a garage for ~ 5 years. I got it running and drove some to see what it needed. The belts were stuck to the pulleys but no squeal and driving cleaned the pulleys right u. I left them on the car for a while, no probs.
Aside: I saw in one of the messages on your forum "2 steres of wood". New word to me - a metric weight-volume measure used in the UK?
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240 drivers / parts cars - JH, Ohio
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Paul240480 is English but lives in Brittany, France.
Stere - http://en.wikipedia.org/wiki/Stere
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You're right Derek, these cars have this problem everywhere. 740's don't.
That's because Volvo started with a design using a three-pulley system on a car with very little alternator load -- back in the 60's on 140's I believe.
The two-belt system is not a redundancy move. These cars need every bit of both belts to grab that tiny alternator pulley with what little wrap the three-point geometry gives. The matched belt obsession is made moot by the variation in tensioning vs. the oil-soaked mounting bushings found in cars 20 and 30 years on the road. The later 80A alternators do offer quite a bit of resistance bringing up a battery from cranking discharge.
All my kids know to turn off the lights (and blower) until the squealing stops, when this does occur. Saves me embarrassment.
The thread you linked was interesting for the picture of the belt worn by contact with the bottom of the pulley -- the one with the "teeth" missing over a portion. Loved that one. Will stick in my mind. Thanks!
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Art Benstein near Baltimore
Remember what Cardinal Cooke once said:
"A man would do nothing if he waited until such time as no one would find fault with what he has done". - originally John Henry Cardinal Newman
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After my Winter car sits through the summer, it squeals at start-up for a few minutes. After a 1-2 drives, the squeal at start-up is gone.
(I put comments from 2 of your posts at bottom). I'm wondering if there is a some cause & effect, as follows.
1. The PO parked the car because of "charging problems". This could be a combo of: the bad ground Onkel suggests, a failing alternator/ brushes, and the excite wire shorting out. If the alternator is getting weak/ intermittent ground, it would be struggling to produce enough to keep the battery up.
I'm in over my head here but: With a partial ground, there's a voltage drop to the circuit. The voltage regulator sees low voltage and asks for more => a high load constantly. The belts squeal in response. Electrical resistance produces heat which damages the ground wire/ connector and perhaps the excite wire.
2. They parked the car after a drive in Winter w/ salted roads. It sat, the pulleys rusted up. When I posted about the rough pulleys earlier, someone said that usual problem was pulleys that were too smooth. These were rough with scale and the belts were trying to grab on the scale - it almost looked like a frame treated with POR-15.
The high electrical load in a 240 hadn't occurred to me (your comment that the 2 belts were needed to handle high-output alternators) - I thought the (2) 240 belts were for redundancy. I rarely had belt squeal in the older (1960s-70s) cars I had but these didn't have computers, electric fuel pumps, CD-stereo ...
Net: I'll remove and clean the crank pulley in case it has more rust than I can see with it on the car; I'll replace the belts with wider ones if I have them.
The new belts I have could have been on a shelf a long time. Belts have a shelf life as well as a working life.
AB: "I would never look to a broken ground wire, as the squeal corresponds with the effective re-charging of the battery just drained in cranking. Although it could be a contributor if the battery never does get recharged because the ground is intermittent. When I say broken, I mean in the fashion Onkel describes, where the connection is poor in one of the ring lugs, not cut in two obvious pieces."
AB: "The two-belt system is not a redundancy move. These cars need every bit of both belts to grab that tiny alternator pulley with what little wrap the three-point geometry gives. The matched belt obsession is made moot by the variation in tensioning vs. the oil-soaked mounting bushings found in cars 20 and 30 years on the road. The later 80A alternators do offer quite a bit of resistance bringing up a battery from cranking discharge.
All my kids know to turn off the lights (and blower) until the squealing stops, when this does occur. Saves me embarrassment."
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240 drivers / parts cars - JH, Ohio
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"Net: I'll remove and clean the crank pulley in case it has more rust than I can see with it on the car; I'll replace the belts with wider ones if I have them."
Sounds like a plan. Especially the wider belts.
The exciter wire really needs some looking into, especially since you stepped over my question about your test light.* There are two major safety system using that circuit, and no, it is not remote sensing for the regulator a la GM or whatever. The "over your head" part is, ah, another red herring. This is really a lot simpler than you make it. Mechanical, except for that red wire you "replaced." Hope you eventually see what I mean.
* Edit. Apology -- I just found your response about the Walmart test light. The one I show (yes I do own one) is an LED version. Like I said, it would see the current a drop of water could pass. In other words, pretty much about as useless at providing a load as a multimeter is. You really need to be familiar with the current your test light draws to infer anything using it on today's and even the electronics of the 80's.
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Art Benstein near Baltimore
"When something can be read without effort, great effort has gone into its writing."
-Enricque Jardiel Poncela
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I don't see the wide belts as an issue. The squeal starts and stops when the alternator is engaged/ disengaged.
I agree that it should have been a simple fix: clean all ground connections; alt not charging & excite wire shows ground => replace wire; instrument lights on while running => new brushes; belt squeal => fix alignment, clean/ rough pulleys, install new matching belts. Add 3 different alternators; 3 sets brushes; 3 dif pulleys.
I must not understand your question about the test light. You suspect a false positive because the light is sensitive? OK, forget the light. Alternator not working; I replace the red wire between the grey firewall connector and the instrument cluster; alternator works.
I do think it is mechanical now - I drove 50+ miles today w/ multiple starts and I'm down to < 10 secs of squealing at idle after start-up. I'd bet that if I swapped alternator belts with my own car, neither would squeal.
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240 drivers / parts cars - JH, Ohio
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No I can't explain your squeal. In your original post you covered every reason I have run into in the pursuit and cure of this hallmark 240 ailment. My most effective fix has been de-glazing the pulley (on the alternator only) with 100-grit and then taking it to the sides of the v-belts if I'm too lazy to replace them. Soft mount bushings don't help and neither does oil spray from a cam seal or cam cover leak. Since many of these cars you work on are new to you, complete with OP foibles, your suspicion the V-belt bottoms in the pulley seems very likely.*
I would never look to a broken ground wire, as the squeal corresponds with the effective re-charging of the battery just drained in cranking. Although it could be a contributor if the battery never does get recharged because the ground is intermittent. When I say broken, I mean in the fashion Onkel describes, where the connection is poor in one of the ring lugs, not cut in two obvious pieces.
Really, I was just surprised at the "excite wire" statement, however much like the red herring it was. I have a "simple test light" -- under $5 at Walmart -- that would indicate through a drop of water. I mean, it is so sensitive, it might just give you the results you got through the leg to the SRS controller. And if your red wire was really grounded, your foray into the dash to replace it should have exposed the reason. What sort of test light do you have? Incandescent? 100mA?
* a re-read of your OP reminds me you've already been there, done that.
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Art Benstein near Baltimore
"Wise sayings often fall on barren ground, but a kind word is never thrown away."
-Sir Arthur Helps
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My test light is the same as yours: a pre- Wal-Mart ~$1.99 unit that I use for setting ignition timing on older motors with points and condensers; and for testing for +/- .
It's rough for sure but the range - bright/medium-bright/dim - helps in quick diagnoses eg. a friend's 240 found that his starter wouldn't always engage. He'd turn the key several times get no response. Finally it wouldn't work at all. I used the test light (hooked to the neg and found D+ on the starter and at the wire from the ign switch when he turned the key.
Put the test-light wire on the positive post of the battery. Had bright ground on the block but only a faint glow on the starter housing. Turned out that the starter was missing the lower bolt and the upper one was loose. It was a re-man unit and fused to the housing - I had to pry it loose with a bar.
But I see your point about getting a false read on the excite wire. I don't know much about the electrical circuits. I was getting a bright ground read at the wire unplugged from the instrument cluster and the connector, it could be the problem. I replaced it; the alternator worked again.
What's odd to me is the sudden failure - the instrument lights coming on and the alternator squeal stopping as the charging stopped. It made me wonder if there was a bad ground somewhere, the excite wire overheated and shorted out.
RE: tracing circuits and grounding problems: 20+ years ago a friend brought a ~1963 MB SL back from Germany. Euro-spec car with Euro lights and the lighting & wiper controls on the stalk (NA in the US version). Everything worked except sometimes eg. you'd engage the wipers and the heater fan would come on slowly; or flashing the headlights would engage a turn signal. Turned out that someone had rewired some of the lights and moved ground wires around. MB then had a grounding block up under the dash and some of those wires were cut.
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240 drivers / parts cars - JH, Ohio
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Now if you do ground D+, the alternator will stop working. And of course it only squeals when it IS working.
I gather your test light is an incandescent light. Much better than an LED unless you re-train yourself. The one I pictured was an LED -- very sensitive. The big problem for me is figuring out which type the guy on the other side of the internet is using! It has taken us four exchanges, and I'm still making assumptions.
That was excellent troubleshooting at the starter. It is tough to know sometimes whether your test light probe is penetrating the oxide skin on things like starter housings and alternator cases.
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Art Benstein near Baltimore
"If a woman has to choose between catching a fly ball and saving an infant's life, she will choose to save the infant's life without even considering if there is a man on base." (Dave Barry)
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Thanks for the reminder. I forgot to mention that in my post.
When I 1st looked at it, the alternator housing had a weak ground (test light between battery + and the housing). The wire itself had ground.
I removed the wire from the back of the alternator housing, removed the nut that anchors the stud to the housing, cleaned all items, placed a small copper washer* on the stud, tightened the 1st nut against it, replaced the ground wire and the harness clip. Now I had a good ground on the alternator housing.
*I have a box of copper washers specifically for this purpose.
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240 drivers / parts cars - JH, Ohio
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You just described what you did on the alternator end of the wire...that is not the end that fails in my experience. Remove the wire completely from the car and inspect it. Often it is the ring connector for the chassis failed internally. The vibration, oil and salt get in under the insulation and create corrosion between the crimp and the wire. Looks fine and works fine intermittently but you can often pull the ring right off if the insulation is the only thing holding it together.
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Thanks for the comment. I agree that this wire can have a partial break at the connector and provide reduced ground; and can be broken so that the ground is intermittent.
I don't think that's the case here: The connectors have been replaced; with the wire removed from the alternator, a steady pull did not separate it at the block end - that's my usual test. And the alternator housing has ground.
I probably will remove it from the block side and clean that up just to be safe. Especially as I don't have any other good leads.
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240 drivers / parts cars - JH, Ohio
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