Car starts and sometimes don't. when it doesn't want to start it is like its dead. how do you check to see if it is the starter relay or the starter?

starter relay
or ignition unit faulty

if the engine turns over when cranking its working. you don`t say what the actual problem is. at the starter on the large terminal you should have battery voltage all the time. on the small terminal you should have battery voltage only when trying to start the car. if you do have power here then while trying to start the car tap the starter if it attempts to turn over the starter is no good. if you don`t have power at the small terminal then you will have to check for power at the solenoid/relay on the inner fender on the drivers side on the S wire when trying to start the car. this wire feeds battery voltage to the starter on the small terminal, if you don`t the solenoid/relay is bad. if you do then you will have to check for a damaged wire from the solenoid/relay to the starter. sometimes the starter motor could have a bad ground connection were it bolts up to the engine.

If you mean that the engine won't turn over to allow the car to start then you probably have a dead battery or bad starting motor or relay. Get battery checked to start. If battery is good check that battery voltage goes to starter through relay, relays go bad sometimes. Finally if voltage at starter then it is most likely the starter that is bad.

check the soulanoid and all wireing. sounds like bad soulinoid or bad connection

Sounds like a starter that is in the 1st stages of death : ) Starters don't just die, (usually) they kinda die a long agonizing death, agonizing for you cuz most of us tend to push it and hope that it just keeps going, Forget it! It's dead replace it and move on. : ) I would def change out the starter though. That'll probably solve your problem. Good luck.

Hello, you may not be getting a signal from the ignition switch to the starter relay. Have you checked the starter relay? Also try jumping the relay with a small jumper wire & see if the starter will engage. I have found this to be the problem on a lot of the early hardbody trucks. Let me know the results. I hope this helps.

Yes! it is the starting point for your check. when the key is turrned it is IMPORTANT to see if the power comes to the solenoid. If there is +12 to the solenoid then the fault is in the starter motor, can be due to wearing of brush or commutator.
If there is no power from the switch then the key switch contacts are bad. Also check if there are any errors that are displayed to prevent the switch from clicking.

When it doen'st start, you will need to check for spark, fuel. If it doesn't have one of these, you will need to start tapping the relay related to starter, and fuel pump. The best way to determine which ones they are is to get a manual, but another way is to place your hands on the relays that you think maybe related and have someone turn the key on. The correct relay will click. Now, you will need to see if the same relays are clicking during the no-start. If any of them fails to click, tap them with a screw driver. If it starts then, replace the relay. It maybe interfering with the radio since this is an electrical event.

Is it one click or multiple clicks. If it's multiple clicks, it sounds like a dead battery. Voltage isn't always an indicator of a good battery, you need to have enough cranking amps to be able to start an engine also. If you have dash lights and it only clicks once, you could have a bad starter. An easy way to check this is to try and jump start the vehicle. If it starts up with a jump start, you need a new battery. If it still doesn't start up and it just clicks, you probably need a new starter.

Good Luck!
~Brandon