Hi, brand new to the forum, and have a puzzle (at least for me)

My inlaws gave my husband their old '89 DX, 215,000 miles, maintained beautifully over the years.... She is a bit 'tired', but runs well for a commuter car....

Except

Last week, the battery, lights and brake dash lights all came on...... Then the AC stopped working.... We checked the battery and there was an issue, so it got swapped out (it was less than a year old, we got 100% warranty trade, our charger was showing a fault code for a blown cell). about 1/2 way home from town (30 miles one way) they came back on again and AC stopped again......

Any suggestions on what to do now (or troubleshoot?) I am much more comfortable working on my 03 Dodge Cummins, it's been a very long time since I have own a gas rig....

 

The alt charge light came on?

The brake and tail light out indicator light came on? If so did this light come on when the brake pedal was pushed?

The AC stopped working as in the AC compressor stop working, or the blower fan stopped working, or both?

If battery is not being charged, this can affect other electrical systems in strange ways.

Obtain a volt meter and check the battery voltage engine off. Then start the engine and rev to 2000 RPM and check voltage.

A good battery will have a voltage around 12.9v. A working alt will increase this to around 13.5-15v when it is charging the battery.

 

I will give that a shot in a few minutes (checking with the meter)

It is the Alt light (too dang long with diesels)

The compressor, not the blower (and that light will flash as well at odd moments when it acting up)

The taillight light is on, yet all are functioning (headlights, turn signals, brake, and reverse), and it came on doing freeway speed, no braking)

Thanks, going to grab the volt meter

 

It is the alternator, thank you

 

Good job.

Thanks for posting back.