Alternator/ Cruise Contol Strangeness
 

I thought I had two separate problems this week, but it turned out to be just one (I think). I've been near DFW, TX all week, I drove from CO to TX last Sunday. While driving to TX, my cruise control stopped working and I assumed I needed to order a new amp. On tuesday, while driving around locally, my alternator light came on (after driving through a fairly deep puddle). The next day my battery was dead so I found a local place to toss in a new alternator. The funny part is that my cruise control came back to life with the new alternator.

I'm guessing that the failing alternator wasn't putting out quite enough voltage for the cruise amp to work, maybe the amp is getting a little weak. I'm driving back to CO on saturday, it will be interesting to see how the cruise holds up. I'll hold off ordering a cruise amp for a while and see how it does with the correct voltage.

I just thought it was strange.

Replaced the alternator on my 77 300d today. It's the week for Colorado alternators.

I guess so, mine must have been getting weak but driving through about 6-inches of water must have been the last straw. It's been a little damp in TX all week.

Update
 

After getting home with my new alternator, my battery died a couple of days later. Alternator is working correctly, but I guess running the battery down to nothing a few times killed it (not much of a surprise). It was only one year old so I got a free replacement.

Voltmeters for everyone!
 

Yet another example of why all cars should come with a voltmeter. The failing alternator and dying battery would have been detectable ahead of time. [Granted that many people wouldn't know what to do with a voltmeter if they had one, but I figure the people on this forum are a cut above average.]

Hint: If your car doesn't have a voltmeter, you can get one and put it on yourself!

Jeremy

when i swap the engine in my car tomorrow or the next day i am going to upgrade my alt to the al192X

I've considered it, about the only place to put one without hacking up the dash is in the ash tray.

I'm thinking I'll just get one and wire it to a lighter plug so I can just check things every now and then. In fact, there is no reason why I can't just get a lighter plug at Radio Shack and hooking my voltage tester to it. I usually have it in the glove box or trunk anyway. That way I won't mess up my dash.

If I try use it for about 10 miles everytime I fill up I figure I won't have any problems sneaking up on me.

That would work.

I assume they didn't consider voltage a "critical" parameter that needed a gauge. A failure of the charging system is mostly just a PITA, and shouldn't result in any real damage (except the battery). In theory, the idiot light will give you enough warning to do something before you get stranded.

BTW, I picked up one of those portable rechargeable battery packs last week so I wouldn't get stranded (about $100 at a McParts store), they actually work very well.