Problem starting my car-

[bGIveNs33]

So...

I have a '90 plymouth colt that has been a fantastic car for me.

The other day I went on a weekend trip in another car and came back and my car was completely dead. No clicking.... when I tried to start the engine, just nothing. I jumped it and it started up right away. I left it running for 10 minutes or so and tried to start it again. It started fine but died within seconds. I could drive it as long as I kept hitting the gas pedal. I did some research and I thought I had a bad battery but I had it tested and it seemed fine. My conclusion is I have a bad alternator. Thoughts? Are they hard to swap out yourself?

 

[IcePickFreak]

Sounds like the alternator. They're easy to swap in concept, but depending on the vehicle they can sometimes be a little bit of a PITA if access to the bolts is hard to get to. I'd imagine on a fwd Colt it's pretty accessible and probably wouldn't take more than 15 minutes to yank the old one out and install a new one.

 

[LTC8K6]

Was the battery load tested?

If you live near an Auto Zone or Advance Auto, they will test out your battery and alternator for free.

 

[exdeath]

Check the cables? Worked fine when you jumped it (bypassing your battery and post connections), ran fine after you jumped it (off the alternator, again bypassing your battery and posts), but still hard to start, and requires high RPM to maintain electrical power (running off the alternator directly).

Alternator is fine, it's either the battery or bad connection at the posts.

 

[LTC8K6]

Yeah, I was thinking that 10 minutes wouldn't do much to charge a really flat battery, so the fact that it did not start after that didn't mean much.