I haven't been using my '88 240 too much lately. The other day I started it up after not driving it for a few days, and several dash lights came on - battery / brake failure / and bulb failure. I revved the engine slightly and the lights all went out. I left the car running for a few minutes and the lights did not come back on.

A friend of mine said that's a sure sign that the alternator is on its way out. Does that sound right? I wouldn't be surprised, since it's the original.

Thanks!

Check page 11 of your owner's manual or see the following copied text from the 1987 Volvo 240 online manual:

"Alternator warning light (red)
If the light comes on while the engine is running, check the tension of the alternator drive belt as soon as possible. (See section titled "Cooling system".)

NOTE: This warning light is illuminated if the alternator is not charging. However, alternator, parking brake, brake failure, and bulb failure will be illuminated at the same time due to the design of the system."

Okay, this tells you that those lights illuminating indicate a failure of the charging system. I have not seen any evidence of Bosch charging systems needing to be "awakened" after sitting idle for weeks or months--this is a specific failure.

Check your harmonic balancer first and make sure the rubber insert has not failed. Your mileage indicates this may be the source of the problem. Go ahead and replace the harmonic balancer if you've never replaced it--it's a wear item and lasts 150K to 200K.

Check your alternator regulator/brushes and replace them as these are also a wear item.

Check your belts though I have my doubts about sudden belt failure, as the alternator is driven by two belts, so there is redundancy in place to make this less likely.

Dimes to dollars, if you do these three things you will discover and correct the problem.

kourt
87 245
austin, tx

Thanks for the info. I actually don't even know what the Harmonic balancer is. I looked it up and I get the crankshaft pulley. Is that what you're talking about?

No one seems to have mentioned the bushings for mounting the alt. I imagine it would be a good idea to replace those as well if I should change out the alternator.

Anyway, the lights aren't coming on anymore, and I've been driving the car short distances. At the earliest opportunity I will probably swap out the whole alternator since I already have one, and see what the old one needs for it to be a good spare.

re: "...don't even know what the Harmonic balancer is. I looked it up and I get the crankshaft pulley. Is that what you're talking about?..."

Yes, that's the harmonic balancer. It's a hefty pulley, and it's in two parts, an inner (bolted to the crankshaft) and an outer ring (which drives the belts), and they're joined, using some adhesive, by an intermediate ring of rubber. The adhesive eventually fails and lets the inner ring spin (driven by the engine) while the outer ring is held behind by the resistance in the accessories (water pump, alternator, A/C and p/s), so they don't turn as fast as they should.
Additional note: since the ignition timing mark is on the outer ring, the timing mark wanders if there's slippage because it's no longer synchronized with the engine's timing belt and other shafts.

re: "...No one seems to have mentioned the bushings for mounting the alt. I imagine it would be a good idea to replace those as well if I should change out the alternator...."

I think you should consider the bushings if you find that the belt is slipping and you can't get it tight enough (to prevent slipping, squealing) without excessive tension (allowing less than a 1/2 inch flex on a segment). The alternator isn't really held rigidly in place, but depends on the bushings for such stiffness. I personally have changed all of mine (all accessories) to poly, but a fresh rubber from Volvo (don't use other brands) are OK, too.

Good luck.

Thanks for the info. It sounds like a good time to replace that would be during a timing belt change.

If the timing is affected, though, wouldn't it be pretty obvious when the harmonic balancer fails?

re: "...If the timing is affected, though, wouldn't it be pretty obvious when the harmonic balancer fails?..."

I might have miswritten -- sorry about that :-(. It doesn't really affect the ignition timing, but only appears to affect it, if the harmonic balancer fails. I wrote, "...since the ignition timing mark is on the outer ring, the timing mark wanders if there's slippage because it's [meaning the timing mark, not the actual timing] no longer synchronized with the engine's timing belt and other shafts...."

Actually, the ignition timing is still synchronized by the timing belt linking the distributor (driven by the intermediate shaft) to the camshaft and crankshaft*. However, the timing mark (revealed by a strobe light against the timing scale on the timing belt's cover) is on outer ring of the harmonic balancer, and since that becomes loose and slips, it no longer indicates the true ignition timing and just rotates around the circumference.

And that's also why a chalk mark, drawn as a radially drawn line on the balancer, will not remain aligned.

[ * your '88 is applicable to that sentence, but for others reading this who may have a '89 or later, ignition timing is no longer determined by the distributor and intermediate shaft at all, but rather by the control of the car's computer (which also takes care of advance and retard electronically instead of a distributor's weights, springs and vacuum diaphragm) with information from the Crankshaft Position Sensor on the bellhousing, sensing the flywheel's tone ring.]

Hope this helped, and sorry for the misdirection of my prior writing.

All of the prior suggestions about checking output are good -- and also check your belts (I find mine needed a little tightening in this sudden cold) -- but I just wanted to add that, if you find that the alternator isn't up to par, don't pay big bucks to exchange your alternator just yet.

On both of my '93's, one at 145,000 mi and the other at 190,000 (suggesting that this point in the mileage is unpredictable), I found that the brushes had worn down to where the alternator exhibited some bad behavior. But instead of the expense of swapping the whole alternator, I just replaced the brush/regulator set.

Buy Volvo p/n 3523710-6, $65.29 retail and cheaper from some online sources.
I've already removed my preheater "stove" (the sheet metal around the exhaust manifold) and duct to the air filter box for other reasons, and with those out of the way I am able to work from above and swap the whole brush and voltage regulator set with the alternator still in place (I don't even have to loosen the belt to move it even a smidgeon), the only tool being a small mirror and a phillips screwdriver (it takes about five or ten minutes the first time, and faster after you've learned to get a feel for compressing the brushes' springs. If you're keeping the preheater system, it might be harder for you, though, and you may have to work underneath, instead.

Hope this helped.

I already have a spare alternator, but maybe I will try just swapping out the regulator. I read somewhere that removing the oil filter helps to gain more access.

How about telling us the amount of miles, you think you have on the alternator. How long has it been since it was last serviced or changed.

I think the brushes are getting short and may have stuck. The last time you drove it was it raining? The belts can hold moisture against the pulleys.

Interesting thought another poster has that alternators sleep. I would have never guessed it could sleep. I sleep when I get tired, so...OK!

Phil

The alternator has 196K miles on it, and has never been serviced. I guess the brushes must be getting short by now.

Yes, I would say it has been on there awhile. You are getting your moneys worth out of it. It does not owe you a thing.

It appears the voltage regulator is still working as good as a new one.

Brushes run from $.50 to a $1.50 each depending who wants to gouge you. I get mine from an auto electric shop that rebuilds alternators; his are 50 cents a brush.

You have to take it out, why not slip in some new ones. It is simple to do. Just do not solder the leads in too short as to keep them extending properly.

Disconnect the battery first! Remove two screws. It only needs about an inch and half clearance to slip out the back.

After replacement of the two little carbon sticks, you hold a couple strips of paper or thin piece of cardboard underneath them. Set the whole works inside the hole and slip out the guides from underneath as it clears the outer housing. Some manufactures provide a hole that leads to the outside of the assembly. On those you use a small wire to hold the brushes up and pull in out after it is in the hole.

Of course, for a few moments more you could just pull the alternator off the car.

I advise this because you can take a better peek at the rotor rings. To see if they grooved excessively deep which in most cases they are not. It will give you a heads up on its overall condition. You can spin it by hand up close to your ears in order to listen to the bearings, just in case they may be getting dry. Another maintenance thing is to blow out the windings of the brush area of carbon dust and road dirt accumulation.

Alternators do a lot of work for us like nothing else can, give them TLC.
Phil

Thanks for the info. Is it really that easy to take off the whole alternator? It looked like the hose coming from the water pump would be in the way, but I guess I wouldn't know until I try it.

If you can solder replace the brushes, otherwise a new Bosch Voltage regulator is easier to replace.
Dan

that's normal for a normaling operating bosch alternator. you always have to goose the gas to get them to wake up. check the charging voltage AFTER the lights go out and then we'll see. good luck, chuck.

That is a sign your belts are slipping...

possible, but not always. been doing this for a long time and have seen it countless times on lotsa bosch cars, not just volvos. yes, i have a belt tension gauge and use it. there's even a rework that will hang a ford volt reg. on the car that gets away from the wake up step and gets better charging at idle. read this thread--

http://www.brickboard.com/RWD/volvo/676329/740/760/780/ford_external_regulator_bosch_alternator.html

good luck, chuck.

Hi Chuck,

I was interested to read about this new (to me) electrical phenomenon of "wake-up" and "lazy" as applies to the Bosch charging system, but the links in the 8-year-old brickboard thread seem to be dead.

I've done some analysis of the EL regulator Bosch uses internally, and some time ago read the theory of operation as written in the "Bosch Bible," and still can't imagine what you are seeing as a flaw in its performance. But worse yet, I haven't yet noticed on our Volvos what you are reporting from your much wider professional experience, i.e., those cars I have voltmeters in charge as I expect them to immediately after startup, that is, once I've rectified any slipping belt, glazed pulley, sorry bushings, or harmonic balancer faults that may have arisen.

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You are good with electricity. What is it you think is going on?
--
Art Benstein near Baltimore

"When you come to the fork in the road, take it."

honestly, i never gave it much thought as to why, just an observation. whether it was a slightly slipping, non-squealing belt or something else unobserved for the cause, i never noticed. just see the lights, blip the gas, watch the lights go out, charging ok?, good.

as far as the dead thread, i just googled it and that 1 came up. i've seen numerous refences to the rework. turbobricks and the like. there was even a guy in nm or ariz who was doing performance volvo and saab stuff, and he sold a kit with harness, reg, brush holder, etc. even have a few spare brush holders i bought to try it on my 78 but never got around to it. still got the parts, not the car. btw, i emailed you the link i found. let me know what you think, you're the ee. thanks chuck.

I imagine a few alts have been changed where deglazing the little pulley, or replacing the bushings and belts might have fixed things instead, but that silent slipping has surprised me. Squeals when its damp out, but slips silently on a dry day recovering the cranking discharge. Could the silence be caused by a bit of stray oil from a leaky seal or cam cover?

The way I proved it on one, was to wire the "W" terminal to a speaker in the car. This way you can hear the actual alternator speed, using the Diesel tach connection. When it slips noiselessly, it isn't obvious to the eye, because it is still turning, and seemingly fast, yet below the threshold for the magnetic load of full output. I think the 240s are uniquely susceptible because of that small amount of wrap on the load pulley in the 3-point belt drive. All entirely mechanical in my experience so far, nothing electrical except the resulting lack of power.

I didn't get an email from you yet, benstein atta cleanflametrap dotcom.
--
Art Benstein near Baltimore

Yogi: "I am going to buy a Volkswagen or a foreign car."

glazed pulleys, use valve grinding compound. and rarely does a bosch rebuilt come with a pulley. i mean bosch brand parts, not someone else's bosch rebuilt in their box. i want the guy who built it to rebuild it.

nice use of the w terminal. how do you tell if it's slipping with the speaker? lower pitch whine? what's a scope do on w? never tried a timing light and a paint mark on the pulley. i never thought there would be no noise while slipping. i don't see any car often enough to hear it wet and dry. and oil leaks aren't a problem on bmws or benzs like they can be on 240s. with bmws, it's bad bushings or tensioners. i'm not including serp belt cars, only v belts.

i think i sent the email to opera or erols. thanks, chuck.

Hmmm, the car did sit through a rain storm, and the belts sound a little squeaky, although they usually do when it's damp out.

Hi,


If your belts are squeaking, then you need to tighten them.


Goatman

With the car idling, measure the voltage across the battery, and report back. Also measure the voltage across the battery with the car not running and report back. With that information, a diagnosis can be provided.

jorrell
--
92 245 315K miles, IPD'd to the hilt, 06 XC70, 00 Eclipse custom Turbo setup...currently taking names and kicking reputations!

Hi,

I took the measurements this morning.

First I checked the battery before starting the car. It was 12.46V.

I started the car (the lights didn't go on this time) and the reading was 14.51V.

I let it run for awhile and kept checking it. The voltage was dropping a little at a time. After about five min. the reading was 14.38V.

I turned off the car and checked the battery once more, and it was 13.18V.

Thanks!

First, that voltage "before starting the car" at 12.46V means it's about 75% charged -- full charge is at 12.65 when taken after sitting overnight. Maybe because of an alternator problem, and maybe because your battery is just getting old (or sulfated from not being properly recharged regularly).

That "I turned off the car and [the battery] was 13.18V" is useless, because it continues to lower its charge until it's stabilized after many hours.

On a cold morning, 14.5V is very good (the alternator's voltage regulator is set for that in cold weather); "after about five minutes the reading was 14.38" isn't more helpful, but if you checked after the engine ran (and you drove) for a half hour (in cold weather) and found the voltage down to 13.5 or so, that would also be very good -- the regulator is supposed to do that. In hot weather, btw, all these voltages should be about a half volt less.

The battery is a few years old (have to check my log to see when I bought it) and we haven't been using the car that much lately, so that makes sense.