We have a 2004 Jeep Grand Cherokee that will not turn over. I had originally suspected that the starter was bad, so I took it off the vehicle and had it bench tested at the local Advance Auto. The stater tested good so I reinstalled it on the Jeep. After doing some more test I’m back to thinking that the starter is defective. So, the question is, can a starter test good on a bench but still be defective?
Here is why I think the starter is defective:
1: When the ignition is turned I can hear relays clicking under the hood, but nothing else happens.
2: The battery is fully charged and shows 12v when I put a meter on it.
3: The main power lead on the starter shows 12v when I test it with a meter.
4: The ignition wire that connects to the starter shows 12 when the ignition is turned.
I had considered that the problem could be the neutral safety switch, but the reverse lights come on when the transmission is shifted into reverse (indicating that the alignment of the switch is correct) and I’m getting voltage on the starter ignition wire when the key is turned. I’m pretty sure if the neutral safety switch was the problem I wouldn’t get any voltage when the key was turned.
Long story short (yeah, I know, too late) I think it’s the starter, but I don’t want to buy one without knowing. Any advice would be appreciated.
If I remember correctly, a 12 vdc car battery that actually reads 12 volts is somewhere between 25% and 50% charged. A fully charged 12v car battery reads 12.6 vdc.
You might want to have the shop load test the battery?
The battery is showing 12.4v on the meter. I defaulted to 12v for simplicity. But you are correct, a fly charged battery should show slightly over 12v.
FWIW, I went out and messed around with it again a few minutes ago. When I have someone turn the key I CAN hear the starter solenoid clicking, but no sound from the starter itself.
You may have a starter relay on the firewall or fender well area that needs to be checked for giving power to the starter solenoid. If so equipped this is a common problem.
Also, check your battery post/terminal connections.
While the voltage may read sufficient, the amperage required to turn the starter is great and your connection may not support it.
Make sure to clean both terminal and post with a cleaning tool, or at least a sharp knife if that’s all you have. You must have good metal-to-metal contact, and a tight connection to supply the required amps.
It’s very common to have enough contact to turn on the radio, fan, lights, etc…, but only get a click when you turn the key to start.
Run a jumper cable between the negative battery post and the engine block. Make sure you have a good clean connection on the block. I suspect your battery ground is wonky (a technical term). It’s good enough to run the lights, radio, solenoid, etc…, but not good enough to carry the high amperage needed by the starter.
I definitely wouldn’t rule out the starter just because of the bench test. Sometimes, just the act of removing the starter and manhandling it onto the tester will temporarily fix it in much the same way that whacking it with a wrench sometimes does. The cheapo bench testers the parts stores use also sometimes don’t put the starters under enough load to catch a marginal one.
I’d agree with double checking that the battery connections are all snug, if that doesn’t work you may just have to roll the dice on a new starter. The fact that you’re getting 12v at the starter when you turn the key rules out pretty much everything else.
Hold the volt meter on the strater while someone attempts to crank it. Or when the lights are turned on and see if it driops. Easy test. Try it directly on the post and then again on the cables. It will tell if you have a bad connection.
If your starter solenoid is like GM products and mounted on the starter itself it can operate but not complete the circuit internally. There are a pair of heavy duty contacts inside that “make up” when the solenoid has been pulled back by the solenoid coil. It will “click” but not work if that is the problem. In that case you need a new solenoid and can change it once you’ve removed the starter. Easy job once the starter is out.
If the solenoid is mounted apart from the starter, like older Fords, you can get a remote starter switch at the auto parts store and bypass the solenoid to trouble shoot it. If that works, new solenoid again. Even easier to replace, no need to remove the starter. I’ve used pliers to short the terminals out to test it, but I can’t recommend that because you could easily start a fire from the BIG spark that will probably happen. Ask me how I know.
Chrysler owned Jeep for a while and I’m not sure what type of system they use. If the solenoid is on the starter proper I suspect it will be like the GM system, if located away from the starter more than likely it’s similar to the Ford type.
Good luck and stay logical.
If there’s a loud solid-sounding click (as opposed to a typical faint click from a relay) when the key is turned to the “start” position, the starter is faulty. Replace it.
Failing the bench means it’s bad. Passing the bench test, however, does not mean it’s good – as mentioned above, the test doesn’t necessarily replicate the demands on the starter on the car.
If this is an intermittent problem, you’ve probably got one (or more) bad commutator segments in the starter motor itself. It becomes a game of Russian Roulette to see if the motor stops spinning at a dead segment after a start cycle.
I’ve had cars with this problem before. It either starts normally, or it gives the resounding CLACK! of the solenoid engaging but no spin. When this happens, a few key off/crank cycles might nudge things just enough to get a good motor winding in contact with the brushes. If you have a manual transmission, you can also try putting it in gear and shove the car forward or back with hopes of getting the starter motor to rotate just enough to find a live segment.
A very loud, solid click (aka a CLACK) could also mean that the engine is ‘frozen’ by mechanical damage (bearing, valve, etc.).
If it’s a stick shift, put it in high gear and push it a bit. If the drive wheels turn, the engine isn’t frozen.