Help with 98 Sonata charging problems

Hello, About an hours worth of driving, the charging system fails, I replaced the battery as per Sears diagnostics recommended that the batter was dead.
(battery was still under warranty, so it was a free replacement) they indicated the alternator was working just fine......... Next day, the same thing happened, dies on me and after an hour or so of driving. After it if cools off, I can jump start it, and runs fine for about an hour again...... I'm guessing the alternator needs replacing.???.. but I've heard there's a separate voltage regulator ??? Any help would be greatly appreciated. THANKS! Dave
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

A couple of things come to mind Dave. With a car that old, grounds and connections always become areas of suspicion. Clean, tight, and solid mechanically at the connector. It's even plausible for faulty connections to be heat related, which would be consistent with it running for an hour before having a problem.
Did you have Sears test the system during a failure period? That would be appropriate. I think, given the description, I'd initially be lean towards an alternator, even though the diagnostics did not point that way. When an alternator is not working properly, the car will run off of the battery until the battery voltage drops too low. At that point, the world ends. I'll bet it's not so much a matter of it cooling off as it is that it takes time to recharge the battery by jumping it.
As for the voltage regulator - I don't know if the 98 Sonata has an external regulator. It's been a long time since I've seen a car with one, so I'd kind of doubt it, but that's a guess. Have you looked at www.hmaservice.com yet? It's a free website by Hyundai and it has service manuals for all American Hyundai's. You'll need to use IE (Mozilla and other browsers won't work), and you'll need to download the Adobe SVG viewer - go to the site requirements link, you'll see. There's a world of information on that site, although it's one of the worst sites that has ever been written, from a web site development perspective. Oh well - guess you can't have everything. That site may answer the question of the voltage regulator.
--

-Mike-
snipped-for-privacy@alltel.net
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I would assume since after you replaced your battery that the problem would be the alternator. I had my sister's 99 Elantra alternator which began failing at 70k miles. The problem with the Hyundai was that I didn't get any indication from the battery light on the console like I would get on my Hondas. From what Hyundaitech was saying, it is a common problem in which the Hyundai alternators (Hyundaitech correct me if I am wrong) will continue to partially work even with a failure which most other car manufactures the alternator will just go.
Don't rule out the possibility that it could be dirty contact terminals to the battery. Make sure to clean these because I have never seen so much corrosion as I did on our Elantra. I ended up replacing the terminal a few weeks ago because it was so corroded that it wouldn't stay on the terminal.
Nick
wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.