Volvo AWD C70 Forum

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Possible alternator problem? C70

My '98 C-70 went dead last week. Battery is 1 1/2 year old. Checked alternator and could not get an accurate reading. Red positive cable to battery was very hot to the touch. Dash warning/idiot lights were flashing on and off. Radio would go on and off by itself. Made it home okay.
Next morning, it started right up. Checked battery with a meter, 13.75 volts when running. Drove fine and dash lights all worked.
Problem is that my clock and odometer remain on all the time with the car parked. Anybody with any ideas? I've checked all the fuses and disconnected the battery for a couple of hours. No luck.
Thanks for any help.

Butchman








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Possible alternator problem? C70

Hot battery cable means poor highly resistive connection. It will be worse in hot weather. Repair or replace positive battery cable then recheck voltages and symptoms. Sometimes the cables corrode internally and become resistive even when they look ok on the outside.








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Possible alternator problem? C70

My alt light came on when the diode board died, even with the key out. Yours sounds like the regulator is about to kick the bucket.

Klaus
--
(V♂LV♂s 1995 854T, 1998 V70R)








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Possible alternator problem? C70

You mean the voltage regulator? Not the alternator? Any idea why the positive cable to the battery is too hot to touch?
Any more help would be of help.
Thanks.










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Possible alternator problem? C70

I'm not sure if the volt regulator is part of the alternator or not. It's common to combine them. The terminal is hot to the touch probably because the alternator is putting out too much voltage, or its spiking occasionally. I would put a voltmeter on the back of the alternator and see what readings you get, maybe put some accessories on, load the system a bit.

Overloading the battery is not a good idea (of course) so this may shorten the battery life. Heat is worse for batteries than the cold, within reasonable limits. I would get this addressed soon as electronic systems don't like voltage spikes, and this could get worse, or leave you stranded. Have any fuses blown yet?

I suspect that the alternator (by Bosch I think) has a built in regulator. With the drive to reduce parts, this a common setup.

Have you checked the battery connections (ground) to be sure they are tight and clean? It's sometimes the cause of electrical problems, and costs nothing to check. You should not need a new alternator/regulator yet. My 95 850 has 180K miles on the original alternator.








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Possible alternator problem? C70

Thanks for the response.
The car has 110k on it. I have never had a problem with it once the warranty ran out.
Any idea why the clock & odometer remain on without the key?
I have a service bulletin from Volvo about the 850's and '98 70 series that had positive cable/high resistance problems. Volvo offered the positive cable as a single item replacement as opposed to replacing the entire wiring harness.

I may just have to take it to a dealer and have it looked at.

Thanks.








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Possible alternator problem? C70

Dear Luis, I would have your battery cable checked and probably replaced. If it is that hot to the touch, it is worn and creating some related problems. In my '01 C70, my independent Volvo mechaninc replaced my positive battery cable because it was very hot and worn and the car only has 40,000 miles. Also, my mechanic replaced the cable that connects from the fuse box as it also was extremely hot and worn.
The car now runs much better and I believe it was the replacement of both cables. Perhaps you have a good indy Volvo mechanic in Albuquerque.
Good luck, Fred.








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Possible alternator problem? C70

Thanks for the reply. I will take a look at the fuse box cable from the battery this weekend. Hopefully this will take care of the problem of the dash clock and odometer being on all the time after the car has been shut off.

Thanks.
Butchman








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Clock and Odometer C70

My Volvo's clock and odometer (LCD) have always been on for the last 169,000 miles, unless the battery has been disconnected.

Our Honda's clocks and odometers go out when the key is removed.

I like Volvo's way because it makes it easier to record the gas mileage in my logbooks.

Otherwise, I agree it sounds like your alternator diode or battery cable are good places to start looking.

-BTC

'98 V70 T5 5-speed, 169k mi, front IPD stabilizer bar, rear factory HD bar, Bilstein HD, Volvo strut tower brace and skidplate, XC grill, E-codes, V-1, Mobil-1 since new. New goal: "Moonshot" (227,063 miles at it's perigee)

"A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools." -- Douglas Noel Adams (1952-2001)







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