'88 Jeep voltage at 13.9

jjkemp3 · 06-08-2009, 09:28 PM

My '88 Jeep Cherokee sits at 13.9 volts (even under the accelerator) with no load. When I turn on the A/C and lights, I drop to 13.15 volts. Alternator and battery are brand new. Checked connections EVERYWHERE. Does anyone have any idea where I should go next?

**octaneman** · 06-08-2009, 10:22 PM

Hi jjkemp3

The external voltage regulator may need to be replaced, the bad part is on some models its located in the pcm on others it's external. Check the amperage on the new alternator it should be 90 or 124. Do a parasitic load test or with a test light check for shorts and see if the battery is leaking to another circuit. Check to see if your hood light drains the battery, sometimes the simplest things cause the biggest problems.

06-08-2009, 09:28 PM	#1 (permalink)
jjkemp3 Registered User Join Date: Jun 2009 Posts: 1 OS: windows 7	'88 Jeep voltage at 13.9 My '88 Jeep Cherokee sits at 13.9 volts (even under the accelerator) with no load. When I turn on the A/C and lights, I drop to 13.15 volts. Alternator and battery are brand new. Checked connections EVERYWHERE. Does anyone have any idea where I should go next?

06-08-2009, 10:22 PM	#2 (permalink)
octaneman Mentor Join Date: May 2009 Posts: 498 OS: WINXP	Re: '88 Jeep voltage at 13.9 Hi jjkemp3 The external voltage regulator may need to be replaced, the bad part is on some models its located in the pcm on others it's external. Check the amperage on the new alternator it should be 90 or 124. Do a parasitic load test or with a test light check for shorts and see if the battery is leaking to another circuit. Check to see if your hood light drains the battery, sometimes the simplest things cause the biggest problems.