When you have multiple systems that stop working, the best suspect is what they have in common, which is the charging system. First check the battery's voltage. If you need help using a digital voltmeter, start with this article:
https://www.2carpros.com/articles/how-to-use-a-voltmeter
If you have to buy a meter, you don't need the auto-ranging feature. Harbor Freight Tools has a good meter for less than ten dollars. You can find them at any hardware store or at Walmart too. I can help with setting it up if necessary.
The battery will read 12.6 volts if it's good and fully-charged. If you find it's around 12.2 volts, it's good but fully-discharged. Charge it at a slow rate for a couple of hours, then check it again.
Once it's fully-charged, check it again with the engine running. Now it must be between 13.75 and 14.75 volts. If it is low, we'll need to diagnose the cause of the charging system not working.
Thursday, May 28th, 2020 AT 4:10 PM