in my wife's 850 some of the warning lights on the dashboard ["low washer fluid"," bulb failure", "low fuel", "generator not charging", "low coolant", "brake", and "park brake" lights] remain dimly lit after starting the car and while driving around. when they really indicate a warning--as when I step on the brakes and the bulb failure lights up because one of my brake lights is really busted--the warning light brightens. I have worked on the electrical system of my 240 [with a lot of patience, by following the lines in the wiring diagram] but have no experience doing any electrical work on the 850. it looks a whole lot more complicated. does anyone, perhaps, have a ready or more or less plausible solution for this problem? is there a relay that needs to be checked and/or replaced? thanks, Daniel
This happens when one of the 3 phases in the alternator is shorted to ground. Putting a scope on the alternator output will confirm if this is a problem, or measure battery voltage with the engine at or above 2000 rpm and the lights, heater fan, rear defogger etc. on. -- Mike F. Thornhill (near Toronto), Ont. Replace tt with t (twice!) and remove parentheses to email me directly. (But I check the newsgroup more often than this email address.)
Thanks for the succinct answers. I suppose this is what happens when you venture beyond a certain, relatively low level of expertise. I'm not sure what the info means that you gave me. Presently the car's battery is dead and needs to be recharged. With "one of the 3 phases in the alternator shorted to ground" do I just replace the alternator (which is only slightly more than 2 yrs old) or do I have to do something else? I have replaced this alternator before and could probably find brushes if those needed to be replaced, but I hate to do all that work only to find out that in my eagerness to hide my stupidity, I overlooked the answer most obvious to anyone who really knows how electrical systems work. I hate to bother you again, but want to be practical. Thanks again, Daniel
If that's the problem, then yes, replace the alternator. You can have it tested at any autoparts store though and I would do that before replacing it blindly.
