I have a RHD 2005 Jeep Wrangler TJ, the check gauges light came on. So we had the battery tested and was told it was bad. So we replaced it with an Ultima Battery. Check Gauges light is still on and the voltage is running right around 11.33 and 11.49. So then we changed the Alternator, I took the old one and had it tested, and it passed the test... So we put it back on. So we have eliminated the Battery and Alternator... We don't know what to check next... If anyone has anything else we could try or if anyone knows what it could be it would be greatly appreciated!!
Voltage still low after new battery and alternator install
- Thread starter khicks201066
- Start date
Start the vehicle up and put a dvom on the battery terminals and see what the voltage is. Then move your positive lead of the dvom to the large wire coming out of your alternator, and your negative lead to the alternator case and see what the voltage is.
In addition to the above, cycle the ignition from OFF to ON 3 times without starting and the code for the Check Gauges light will be displayed in the odometer readout. I've see a similar issue come up a few times when the field wire shorted, set P0622.
Remember that the voltage regulator is internal to the PCM. If it's bad you have 3 options (listed from most to least expensive):
1) replace the PCM
2) repair the PCM
3) install an external voltage regulator
1) replace the PCM
2) repair the PCM
3) install an external voltage regulator
ATCKIP
Member
The generator field wire is likely shorting between the alternator and the PCM. The wire you're looking for is DB/DG. You could also try moving the connector around at the alternator to make sure the issue in not there at the connector terminals.
With a RHD TJ the layout is a bit different but I expect the wiring runs from the alternator, over the oil dipstick tube, then to the driver side of the engine block and back behind the head to the PCM. You're going to have to follow the loom and look for where it may be rubbing then open it up and inspect the wires.
I've seen this 3-4 times and the loom can rub on the oil dipstick tube bracket, side/back of the block - probably a few other places as well on a RHD TJ. If it's just a single strand you can probably get by with taping it back up. Otherwise you'd need to spice in a new section of 18 gauge wire. Also: If you notice the loom is routed between the coil rail and the block, pull it out and have it resting on the coil rail instead so it doesn't rub against the block.
The generator is inside the PCM but I haven't come across a confirmed failure of this circuit in an '05-'06 TJ so it's most likely a wiring issue. Once you find it, it should be easily repaired.
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What is an Ultima battery? Do you mean Optima?
And if the battery itself is not measuring the right voltage when the engine isn't running, that's caused by nothing but the battery. A fully charged conventional automotive battery will measure 12.6 volts. A fully charged AGM automotive battery like an Optima or Odyssey will measure 12.8 volts.
And if the battery itself is not measuring the right voltage when the engine isn't running, that's caused by nothing but the battery. A fully charged conventional automotive battery will measure 12.6 volts. A fully charged AGM automotive battery like an Optima or Odyssey will measure 12.8 volts.
Did we ever get the fix for this problem? I am having the same issue. New battery and alternator and the check gauge light continues to be on. Did this end up being an electrical wiring issue?
Do you have a DC volt meter? If so measure the battery voltage both with the engine running and without the engine running and tell us what it measures. With and without the engine running.
I went back and checked all my wiring. The wiring harness in the back of the alternator wasn't engaged completely. After I "clicked" it all the way in the gauge went to 14. My battery was bad. Thank goodness it was an easy fix. Thank you for your reply.