Alternator worked fine until recently but with no dash warning (idiot) lights I am wondering if it is something simple? Alternator / battery bulb is good and small wire to alt appears good as well as the alternate ground.

Checked fuseable link on back of cluster.

Any ideas are appreciated.
Dan

Hi Dan,

Given you checked so thoroughly as to include the flex fuse in the cluster, I would guess you mean there is nothing amiss about the dash warning lights; that they test OK in lamp test mode, and do not light when the engine is running.

The "something simple" is usually short brushes. Can you look?
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Art Benstein near Baltimore

"Fighting ambiguity where it persists since forever"

Art
None of the dash warning lights work including the bat / alt light. I tested the bat / alt light only and it worked.

I think the brushes are OK but not sure.
I just pulled the plastic pan off and will check brushes, they have a hex head on them only enough.
Thanks
Dan

Art

Good length on the brushes but Oddly enough they look like they got hot and have deformed at the ends on the Bosh regulator.

What is lamp test mode, new one to me?

Dan

Dan, I can't picture deformed brushes, and also I still don't understand what you are saying about the warning lights.
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Art Benstein near Baltimore

"I don't think you can get cold in Volvo 240 series. The AC can't do it and the heater won't let you." -darkdelta

Just added a picture, looks like they got hot?

No dash warning lights work, I pulled the cluster and tested the alt / bat light manually and it works.

What is the light test mode you referred to?
Thanks
Dan

The photo isn't very clear, but I think I see side load wear on the brushes. They are made from carbon, so they don't melt, but it could look that way in the fuzzy picture because the slip rings are out of round or deeply grooved and the end play on the bearing has increased significantly.

Edit: I see your second photo now, clearly. I think your alt is in need of a rebuild.

Lamp test mode (check owners manual) switch to KP-II and see all the warning lamps on. This is so you know the light bulbs are good. Three of them besides the battery lamp depend on the alt for lamp test: Bulb failure, brake failure, and parking brake.
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Art Benstein near Baltimore

You know that indestructible black box that is used on airplanes? Why don't they make the whole plane out of that stuff?!

Art

With no lights on the cluster in KP-II mode does this indicate a switch problem?

The one slip ring I can see with the Alt installed looks fine.

Dan

"With no lights on the cluster in KP-II mode does this indicate a switch problem?"

It is possible, but since then you've said the fuel gauge works, so that means the cluster is getting power from the ignition switch.

"The one slip ring I can see with the Alt installed looks fine."

Once you've had a look with flashlight and mirror, you should "look" with your fingertip. Loosen the belts and slip them off of the pulley so you can spin the alt and feel the runout and endplay. If not this alt, then some alt where this brush pack lived previously has some mechanical problems.
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Art Benstein near Baltimore

A dyslexic man walks into a bra.

When I got it out both slip rings looked fine.
Thanks again
Art

and one more thing....just because it's esy, and you always make a ;oont of reminding me,,,,ground wires, can look good but be bas
actually I can barely imagine this for you...but as i tell my son...easy isn't illegal...
Happy Holidays

Paul

Art

I just added a better picture. No lights work with switch on KPII.

Dan

If no lights come on, that is a problem in the cluster. Double check, you should at least see the CEL, SRS and oil light, and see if the fuel gauge responds. Did you get the L shaped plug back on the speedo?
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Art Benstein near Baltimore

Two fish swim into a concrete wall. The one turns to the other and says "Dam!".

Fuel gauge does work but the other 3 you mention do not, the only bulb I checked manually is the bat/alt one.

I will replace the alternator with a good spare I have.

Thanks again
Dan

As long as you have it out, I would replace the brush/regulator, is the most obvious......and who knows you might catch a break for once
Paul

Before you install a new alternator, you might want to get the cluster straightened out. The warning lights should all come on in KP-II without the engine running. In particular, the Bulb Failure, Brake Failure, Parking, and Battery lamps should light when you supply a ground to the end of that small red wire that attaches to the alternator D+ terminal. Without that working, you will not know whether the alternator replacement succeeded.
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Art Benstein near Baltimore

I went to buy some camouflage trousers the other day but I couldn't find any.

How best to ground that small red wire to test? Is that the exciter wire?

I have a problem with an 85 245, hopefully you can help.

Car is not charging so I did the above test.

Key in KPII the Parking lamp came on full but Bulb Failure, Brake Failure and Battery lamps lit only very dimly. The voltmeter I have in the dash read about 10-11 v., just above the red. Turned it off.

Tried again right away and then all lamps lit fully and voltmeter read about 13v., halfway on gauge. So I started the car and all was well for a minute at idle and voltmeter started to waver and slowly sink down. So I revved it and the volts went back up but then dropped right off again at idle and would not come back up.

There is a click in the dash behind the vents that seems to be coincident !?

Car has a new wiring harness from Dave Barton.

Alternator is an Autozone reman.

Any help appreciated. TIA.

Another major difference in the charging system between yours and the 91 in the topic of Dan's thread is that the pre-exitation voltage for your alternator passes through fuse 13, which has other systems on its load side. Clean that fuse first.
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Art Benstein near Baltimore

Wisdom comes with age, but sometimes age comes alone.

Thanks Art.

I will try that before anything else then.

Also, could you elaborate on how best to ground the exciter (small red) wire at the Alternator? Just jump a lead from it to any ground?

Not sure anymore to whom and regarding what car I'm responding, but assuming you want to ground the exciter wire to be sure the D+ circuit through the cluster is working correctly, you would connect it to something you are absolutely sure is going to provide a clean return to the car body.

This kinda excludes iffy grounds like the alternator's case, which depends on it's own fallible ground wire, and hardware like the strut mount studs where corrosion can fool you.

I like to use the braided radio interference ground between cam cover and firewall, because it is fairly reliable as a place to make a good connection to a clip lead. The negative battery terminal also affords a reliable place to attach a clip. The downside, of course, is neither is very near the end of the D+ wire, so your clip lead needs to be like 2-3 feet long.

The reason you need all this reliability, is you can't observe the lamp and make the connection from the same spot, so you have to be able to trust your ground. If you could just use a test light of sufficient consumption to verify the ground, the question would be moot.
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Art Benstein near Baltimore

"I feel sorry for people who don't drink. When they wake up in the morning, that's as good as they're going to feel all day." -Frank Sinatra

I just connected a jumper wire from the D+ terminal to the braided ground at the valve cover/firewall.

The Dash lights all lit up brightly.

Removed wire and lights very dim. Also no change in voltmeter, just above the red.

The fuse good, as per you other post.

Car runs like normal.

What does it mean?

I assume this is my post that got you started on this:

"Before you install a new alternator, you might want to get the cluster straightened out. The warning lights should all come on in KP-II without the engine running. In particular, the Bulb Failure, Brake Failure, Parking, and Battery lamps should light when you supply a ground to the end of that small red wire that attaches to the alternator D+ terminal. Without that working, you will not know whether the alternator replacement succeeded. "

The engine is NOT running for this test. The wire is NOT connected to the alternator. They key is in KP-II. You are testing to see if the circuits in the cluster and the red D+ wire are functioning.

If you ground the alternator's D+ terminal before starting the engine, it will not charge the battery. If you ground it after starting the engine, it could possibly damage the small diodes in the alternator. In the test above, you ground the DISCONNECTED wire end, not the alternator's terminal, and you do it with the engine not running.

Anyhow, you ask what it means? If the test passes (lamps light) the problem is on the alternator side of things. Could be one of several causes, e.g. ground wire open, brush pack defective or not installed correctly, belts not driving pulley at speed, defective alternator...

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Art Benstein near Baltimore

Everything is okay in the end. If it's not okay, it isn't the end.

Thank you sir.

Turned out to be a bad ground wire. Replaced it.

Thanks very much Art and sorry for the confusion.

You are responding to the same person re the 85 245. I posted as a guest claiming to be CliveAlive till I was able to login. CliveAlive was an old login of mine that I lost the password to!

I will test it the way you describe!

It sounds like either the voltage regulator is bad or the attached brushes are worn to far to be in good contact/

I would remove the voltage regulator and inspect the brushes, if they are very short either replace them or buy a new Bosh regulator which includes new brushes.
Dan

Thanks Pageda,

I don't really want to mess with this Autozone reman anymore. I have replaced it twice already. So if it is the Alternator it's time for a pukka Bosch one, like you said! I just want to be certain it is the alternator.

I know this is an old thread - but in a search, it seems the most relevant to my problem, except I have an 85 245DL.

I just did the test you describe above, Key in KP II and at first try the Parking Brake light came on full strength, but Bulb Failure, Brake Failure and Battery lamps lit very dimly. I started the engine and the Voltmeter in the dash read about 11v. Just above the red.

I then turned the car off, and tried again, key in KPII and this time all the above lights came on full strength, the voltmeter read around 13-14v so I started and idled the car for a couple of minutes. As I watched the voltmeter (in the dash) it wavered but came back up to 13-14 as I revved the engine. Then slowly drifted back down to 10-11v. where I shut it down.

I also hear a click in the dash behind the vents which seems to be coincident.

Car has just had a new wiring harness with one from Dave Barton. The alternator is an Autozone reman.

Should I try grounding the small red wire at the Alternator and if so how best to do it? Or does this sound like a problem with the cluster

Well the alternator fixed the bulb and charging problems!

Dan

Okay, no sense in questioning success. Will check back in a week and see if you have any update.
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Art Benstein near Baltimore

Two cows are standing next to each other in a field. Daisy says to Dolly, "I was artificially inseminated this morning." "I don't believe you," says Dolly. "It's true, no bull!" exclaims Daisy.