My car will not start unless I jump it?

If the vehicle is starting with a jump start, chances are either we have a weak connection at the battery or even though the battery is charged, it is not strong enough to crank the engine.

As far as the relay, it is located in the vehicle, under the dash, behind the glove box. See pic 1.

What I suggest is this. First, make sure the battery terminals are clean and tight, free of corrosion.

If the terminals are good, get the vehicle started and take it to a parts store. Have them load-test the battery just so we can confirm that isn't the issue.

If the battery checks good, then I want you to try this test on the alternator. All you need is a voltmeter or multimeter. The battery may be getting weak as a result of not charging.

https://www.2carpros.com/articles/how-to-check-a-car-alternator

Let me know what you find or if you have other questions.

Take care and Merry Christmas,

Joe

Thank you, thanks for help on f150 ford ,you won’t believe this right after I got f150 ford fixed with your help and ready to go take it the next day to the smog, a U-Haul truck smashed in the back of my truck lucky I was parked and wasn’t driving, crushing the bed bumper and the frame rail all that work for nothing.

Hi,

Wow! That isn't good news. I hope you weren't injured.

Have you had any luck with the Cadillac?

Let me know.

Joe