Nissan Repair: 94 Nissan Pathfinder, jumper cables, wifes car

Question
I have changed some relays because my wifes car would not always start and she had a guy look at the ignition switch but when I replaced the relays it was working fine.Now that the weather is warming up you have to jump it off,I mean the battery is fully charged and when you turn the key all guages work it just will not try to start but you can hook jumper cables up and it starts every time.It also seems like some mornings it starts except on hot and humid days and on days when the motor warms up it wont restart without a jump.I need samoe advice on what to check and try?

Answer
Hi Ricky -

I say it is the battery. Although it may seem fine as far as lights, when you engage the starter it requires a lot of power. The battery could be failing under load. A good way to test it is to turn the lights on and try to start the car. If the lights go dim, or even turn off, then the battery is the cause.

Hope this helps -
aloha
calvin