Check engine light

DAVID3242

MEMBER
1993 JEEP GRAND CHEROKEE LAREDO
4 CYL
FWD
AUTOMATIC

Check engine light comes on and the battery gage goes down low while driving, had the altenator and battery checked nothing wrong with the two, and idea what it might be

Wednesday, March 16th, 2011 AT 10:16 PM

3 Replies

RASMATAZ

MECHANIC
75,992 POSTS

https://www.2carpros.com/articles/service-engine-soon-or-check-engine-light-on-or-flashing

Have the computer scanned for code/s-you have a problem within the engine management system that caused the CEL to turn on-This is your starting point of diagnosis,finding out what's going on

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Wednesday, March 16th, 2011 AT 10:18 PM

CARADIODOC

MECHANIC
33,916 POSTS

The alternator has to be tested while the problem is occurring. Worn brushes are a real common cause for intermittent operation. You can diagnose that with two voltage readings on the two small wires on the back of the alternator but those readings must be taken while the engine is running. One will have full battery voltage. The key is the other one. It must have less voltage but not 0 volts.

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Wednesday, March 16th, 2011 AT 10:33 PM

CJ MEDEVAC

MECHANIC
11,005 POSTS

Most popular Auto Parts Stores will check your codes FOR FREE!(Reason for the Check Engine Light being on) When you get this stuff diagnosed/ repaired. Be sure you return here for further assistance/ Let us know your findings are, or what was your fix.--The Medic

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Thursday, March 17th, 2011 AT 12:11 AM