I just recently purchased a battery from Lea Schwab..they claim to have run all diagnostic test for battery and alternator ..now my check start system alarm is illuminating constantly and I'm losing power to certain electrical functions (power windows..windshield wipers..heater) .they are functioning but at slower speeds than normal..i brought my car back to Les Schwab and they said they ran all diagnostic test and concluded that there is a glitch in my electrical system..i know this is not the case..is it possible that my alternator my be going out dispite what Les Schwab is telling me?
Hi there. In order to give you the best information I would need to know what kind of vehicle this is. From what you are explaining though it does sound like there is an issue with the electrical system. These problems can occur if the battery that was installed in the vehicle is too small or if the alternator is not charging properly. Most of the time though it is caused by high resistance in the positive battery cable or loose or dirty connections on the negative battery cable. Both of these will cause this. I usually check these connections and cables first an then load test the battery and the alternator. It can also be an ignition switch, but that is not as common. If you want to have this electrical problem looked at, consider YourMechanic, as a certified mechanic can come to you to [diagnose the problem within the electrical system] https://www.yourmechanic.com/services/electric-problems-inspection
Have a car question? Get free advice from our top-rated mechanics.
Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing