BOTH problems ALL started this past Sunday.


-------------PROBLEM #1
* While driving on highway, ABS & TRAC OFF warning lights came on in the dash & stayed on until car shut off.

(NOTE: Today, my mechanic got the ABS & TRACS OFF codes to come up on his diagnositic machine, but he could not read the fault details)


------------------------------------------------------------


-------------PROBLEM #2
* All DASH LIGHTS started dimming intermittently while driving; or when driving at low speeds while switching between Reverse and Drive.
* RADIO began shutting off for several minutes at a time.
* High & LOW BEAMS would dim as well.
* When braking, BULB BURNT OUT light now comes on.
* TURN SIGNAL sounds normal when waiting to turn; clicks faster when using gas to make turn.

(NOTE: Today, my mechanic tested everything... including the alternator that was recently replaced a few weeks ago, and the voltage was fine.)


What is going on? Any help would be greatly appreciated!!

 

I have the same problem and I cant figure it. The alt. is good, the battery is good, but I will be driving and my radio shuts off, lights dim, and the engine dies. Any ideas?

 

The 850 im not sure what year it is but the ABS module might be bad.
The lights I will bet is a bad dimmer switch.

The S70 it has to be something in the main wire from the battery.
Check the main power wire at the fuse panel.

 

[QUOTE=tech;145996]The 850 im not sure what year it is but the ABS module might be bad.
The lights I will bet is a bad dimmer switch.QUOTE]

Thanks for your help.

I forgot to mention that my 850 is a 1996 model, with almost 430,000 km.

I am thinking my ABS module is done... and I am thinking of removing it and sending it to Viktor.

Q: Is there any way to make sure that it is the problem before sending it off and realizing that it is not the problem?? However, I have seen something that ~90% of the problems with the TRACS OFF and ABS lights are due to that module going south...

-----

The dimmer switch may be the problem with the lights (it had some erratic performance issues - 'flickering the lights on and off' - in the past) BUT...

Q: How come the radio shuts off at higher than 40km/h speeds, but usually turns back on when I have driven slower than that.

Hmmm....

Thanks for your help and any additional advice you may have.

 

Check for all ground wire terminals under the hood and also make sure that the second RED wire on the battery terminal is nice n' tight.

 

Could you clarify those two points??

Check Ground terminals under the hood for what -----> for the ABS module??

The SECOND red wire on the battery terminal of what -----> for the dimmer switch????


Thanks again.

 

I'm still suspecting the charging system fault; the alternator/its connections. Was it a rebuilt Bosch? I would hook up a digital multimeter across the battery, start the engine and rev it to see what readings would be observed. If you don't have a multimeter yet, it is a good investment and all you need is a $20-$30 Sears Craftsman meter.


JPN

 

+1 jpn

 

+1 arzy.

FYR; see attached.


JPN

 

I had my rebuilt alternator replaced due to the voltage regulator OVERCHARGING the battery -- it was like 19.6 volts when I had it revving between 1500-2000 rpm and had as many accessories and heat on!!!

So far (one day) the NEW alternator is going fine. The lights are off the dash... EXCEPT for the 'bulb out' light bulb.

I already replaced both LOW beams when this happened, then when the regulator was replaced yesterday, I replaced both HIGH beams (because they were both burnt out)... but that light is still on. NO bulbs are burnt out on the rear, nor are any signal lights burnt out...

Any ideas on why this 'bulb out' light is still on?????

Also, the ABS & TRACS OFF lights are off now since this new alternator was installed yesterday! (hopefully they won't come back on!)

Thanks!

 

Car 1997 VOLVO 850, 138,000 miles. Intermitten issue with dash lights dimming while driving, then they come back on and works for while again.
I will be driving and my radio shuts off, lights dim, and the engine dies. Any ideas?
All DASH LIGHTS started dimming intermittently while driving; or when driving at low speeds while switching between Reverse and Drive.
* LOW BEAMS would dim as well. When changing to high beams it would kill the engine.
* TURN SIGNAL sounds slow when waiting to turn;
New battery, New terminal connectors to battery,second RED wire on the battery terminal is nice n' tight. Alternator was tested good. Switched out headlamp switch,

 

I still suspect the charging system. Is the alternator a rebuilt/new Bosch? And is it putting out the specified voltage? If so, is the serp belt the tensioner in good condition? Lastly, what brand battery did you install? Cheap franchise batteries are not worth the money.

If the above items still seem ok, wait for Tech's advice. In the meantime & as a last resort, you can make the ECU "re-learn" idle speed. As of today, I am not 100% sure if this is the correct method but it worked for me a few times:

1. Turn ALL electrical loads off.
2. Leave the shifter in "P" and release parking brake. Chocking the wheels is ideal.
3. Leave your foot off of the brake pedal.
4. Start the engine and let it idle for 10 minutes (Ideally, idle until the cooling fan kicks in but it may take up to 20 minutes).

That's all I can say at the moment with limited info.


JPN

 

If your ABS computer is going bad (which will happen on all 850s over time) the warning light will not always be on. My ABS computer went this summer and here was a typical scenario with the lamp:

1. While driving, the lamp would come on at random.
2. When I started the car the next time, the lamp would usually be on.
3. If the lamp was on, it would usually go out once the car reached a speed of ~15mph.
4. The cycle would repeat.

There are at least three different guys in the USA who repair these computers and restore them to standards higher than the original. They also cost far less. I had mine refurbished for a total of $180 after shipping and the work came with a five year guarantee; the Volvo part would have cost $800+ and the part probably would not have come with any warranty (and would have failed since the guys who rebuild them know what they are doing).

As far as batteries, I have a DieHard International (Sears) and can highly recommend it.

 

My favourite has always been Interstate Batteries (in addition to top quality products, they come with free jump start services+).


JPN

 

Could also be an issue with the ignition switch. If your car is a 94-95, you can check the ABS codes to see what the issue is.

Also, jiggle the ignition switch the next time it happens and if it seems to fix the issue. If it does, it is the ignition switch. You can get it here.

 

+1.


Jpn