alcr4

A few days ago my car would not start I jumped it and it ran fine for a day or so. Again it would not start so I jumped it again but when I went to start it again..nothing. No clicks noises alarms or anything. I bought a new battery thinking that might be the issue. It started fine but when I went to start it again, again nothing so I replaced the alternator. Again I am having to jump it every time to start it. I have checked the grounds and they are fine. All of the fuses are ok. When I do jump it, it runs rough like it wants to die but it dosent. Any suggestions what to look for next? Please help...

alcr4

I have also tested the new battery and it is fine. I am not positive on how to test the alternator..

92 civic ex 4dr

Where did you buy the alternator from? I have never had any good luck with Autozone parts, especially with their alternators.

TheMuffinMan

iTrader: (1)

When the car is running, the alternator should be putting out around 14V to the battery. If you aren't seeing that it could be the issue.

tim73

If it will run, then it sounds like a battery/connector issue. Did you have the old battery load tested before you bought a new one? Did you have the alternator tested prior to buying the new one? Have you ensured all connectors are good and clean, both on the battery itself, and on the positive and negative connectors? If the battery checks out, then do a resistance test from the positive battery lead to the starter, it should be close to .1ohms, higher than 5 or 10 ohms, and you have some corrosion. Also, check the ground on the block to the negative terminal on the battery, should be less than 5 ohms. Also, check the negative terminal on the alternator to the negative terminal on the battery, again less than 5 ohms.

To find electrical gremlins, best to use a diagram. Checking grounds visually isnt very accurate. Best to use a VOM. Less ohms is good...high ohms bad.

holmesnmanny

On a cold start, start it up and test for voltage. It should be atleast 14v. Then turn on the headlights and the rear defrogger. It should be atleast 13.5. If not, then the alternator is bad and likely not charging the battery enough to start it up.

The alternator is at full capacity at 1500 rpms or higher so on a cold start you are atleast at that point so it's going to giving you its all. This is the best time to test it.