Hello, i have a 1992 volvo 240 wagon. The last month it started to die on me like i had turned the key off, and would not restart. NO crank nothing. I checked the battery and it was dead, I bought a new battery issue persists so new 100 amp alt still dies. It will sit and idle all day but if i try to drive it after about 10-15 minutes it will die, dies faster if i have accessories on (lights, ac, etc). I went through all the grounds cleaned them and added a few new ones. Any ideas where to check or what to do?

 

When you turn your car on turn key to position 2 but dont start it! Check to see if your light/ battery bulb ligjt indicator is illuminated. If it is not than you must replace your bulb to that location!!
that bulb works with your alternator charging/ excitor wire and if its not on prevents your alternator from even working/ charging thus allowing your car to only run on battery only!!!

Simple fix just replace the bulb

Goldenblock

 

Very true. The alternator is turned on using power through that bulb.

I will just add that about half of life's problems require a voltmeter to solve, and they are so very very cheap. Please do get you one.

 

The battery light does work and has already been replaced. but i can throw a new one in there and test if its charging with a new one. Ill start there and let you know!

 

Alternator ground strap connected. Small wire from "Alt" light not connected to back of alternator or damaged. Battery voltage when engine running?

 

I replaced the ground from the back and added another to the body off the alt. With engine on with no lights or ac opn is at 14v, if i turn on ac or lights idle gets low and it drops to 11-10v drops down to 9v if i give it some gas. When i let it idle again and turn lights and a/c off it jumps back up to 14v.

 

Check battery cables. These voltages are measured across the battery terminals?

 

Those readings came off the alt its self. The ground cable off the battery is new and i cleaned the area connecting to the body.

 

You have a bad alternator. (yes it may be new)
Unless the belts are slipping so badly the alternator is not spinning properly under a load - I trust you still have both belts on.

 

Dang i spent a good bit for the 100 amp. i guess i can get a new one and see if the problem continues. and yes belts are good and tight

 

If you need any Oem Alternators voltage regulators or v belts i have over 40 alternators available! Ready for shipping
contact L&D Volvo parts atl Craigslist
Hit me up brother!!

Goldenblock

 

I have an update, the new 80 amp alt is in and the car runs. I drove it for 40 minutes and it still has a problem. It doesn't just die now it seems fine but the ac will drain it down again and make it want to die. SO progress it doesnt just die now but i cant drive it with ac, lights, or radio ect. The first 15 minutes everything worked no problem, then the abs light came on and it got slugish. Turned it all off and got where i needed to be. i was scared it wouldnt start back up but it did and got me home. tested off the battery when i got home at it was "charging" at 12.60-12.70. Any ideas.

 

I was thinking maybe its the wires coming off the alt that may need to be replaced. does anyone have a diagram or know where they lead too? DO they hit battery first or go through the starter.

 

If you think there is too much resistance in the large B+ wire that goes back to the battery - test it with a voltage drop test. Test the voltage with one lead on the positive output of the alternator and the other lead on the positive terminal of the battery. Yes positive to positive. If there is no resistance volt reading should be 0. Any reading more than a volt indicates a high resistance in a connection between the alternator and the battery.

The small d+61 wire goes directly to one side of the alternator warning light bulb in the dash.

 

Awesome ill try that, when i get home thank you.

 

no resistance there. I guess ill have to bite the bullet and take it to a mechanic.

 

Certainly - 12.6 volts with engine running and no electrical load - The alternator is not charging - that's real close to the voltage in a fully charged battery. Measure the voltage at the battery - 12.6 volts. Turn car off, still 12.6 volts right?

Alternator has 3 wires. Big red B+ - goes to the starter then the battery
D+ 61 small red wire - goes to one side of the alternator warning light bulb in the dash and can tell the regulator to excite (start) the alternator charging. As long as the light comes on with the key and goes off when started - it's working.
Ground wire from the alternator case to the engine block (only needed because the alternator is mounted in rubber).

I would expect a good alternator with belts that are tight enough to spin the alternator to be charging at 128.-13.2 volts @ 1500 rpm with a fully charged battery. That voltage will be higher after first starting the car, or if the battery is weak, but should be at least 12.8 volts at all times with accessories turned on. If not - the alternator is not charging. I do understand this might be the 2nd alternator you have tried. Where are you getting these alternators? What the brand? What brand of voltage regulator is on your newest 80 amp?

Even with a good alternator a generic shop is going to tell you the alternator is bad - Volvo's have a lower charging rate than many other cars.

 

Remy is the latest 80 amp, and the other one i just took off was bosch 100 amp. Im not sure what brand regulator is on it. i got the new one off parstgeek.com and the 100 amp from i think it was oreillys. the Battery light does come on when key is in the on position and turns off as soon as it starts. I replaced the ground off the alternator with a new one and cleaned the area before i put on the 100 amp. The voltage off the positive off the alternator is 13v but at the battery is 12.6, it progressively lowers if any accessory is on.

 

Some auto parts stores will test alternators if you bring it into the store. (hoping to sell you a replacement, and making sure if they do you might be actually replacing a bad part)

 

OK can they test the 100 amp thats out of the car? I dont know if they strictly test it while installed or not.