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Last Friday night I posted a thread about how I blew diesel all over the engine comartment, put a new filter/o-ring on, all of a sudden the batteries were dead, went and bought 2 new ones, truck started right up and other than still cleaning up the mess, everything has been fine since Saturday morning. Tonight I go out to start the truck and the Batteries are dead.
One of my questions is, wouldn't the battery idiot light come on if the alternator wasn't charging? And...if the alternator is working, what could be drawing down the batteries since I last drove it Monday evening?
Alternator, $140 + $85 core charge, fixing this problem, well you know...
run this test...disconnect both cables on one battery, on the other battery, disconnect the neg cable and place an amp meter in between the cable and the battery post. you will need to disconnect the underhood light, keep all doors closed and then see what the amp draw is. if you have more than a fraction of an amp draw, you will need to pull one fuse and one relay at a time untill you locate the circuit that has the draw on it...you have 2 fuse boxes to check. if that doesn't change the draw reading, then disconnect the alternator wiring. the alternator can have one bad diode and still charge to some extent.
Normally I avoid schucks at all cost but.... If you need a new alternator the replacement policy is solid. I had some bad wiring in an 88, 7.3L that ate alternators; three times in one year they replaced it w/ no questions asked.
Thanks fedextech and huskerfordfan. I took both batteries out last night and charged em up. Also took out the alternator to go have it bench tested today. If they say the alternator is good, then I will be doing the test fedextech described. Thanks again.
Have 2002 I bought new. First year the batteries went dead. Finally got dealer to test alternator and sure enough it was bad althought I NEVER got the idiot light. I now have a volt meter gauge. Good luck
Thanks, I started looking for a voltmeter gauge today. Had the alternator bench tested this morning and it was bad. Put in the new one so hopefully everything is good. I think I'll still do the test Fedextech explained though, just in case. What kind of gauge did you get and where did you mount it?
A multimeter with a 10 amp fuse works best for this test. It'll read down to milliamps. You can also use a standard incandescent 12v test light as a quick and dirty test. If the light glows when you bridge the gap between the post and the cable with the test light, there is enough of a draw to drain the batteries. No glow, good to go.
Thanks Kwik. I was wondering where you were on this one. Like I said I'm still doing the test in the morning. Afterall, the parts store guy doesn't have anything to gain by telling me the alternator was good.
Got gauge from J. C. Whitney and mounted it with EGT, Boost and Tranny gauges on a quad pod pillar mount.
Originally Posted by Orezona
Thanks, I started looking for a voltmeter gauge today. Had the alternator bench tested this morning and it was bad. Put in the new one so hopefully everything is good. I think I'll still do the test Fedextech explained though, just in case. What kind of gauge did you get and where did you mount it?