weird goings on 99 expy
- Thread starter Kermit
- Start date
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stamp11127
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Who tested the alt and did they give you a printout of the alts performance or did you see the readings?
They should give you the output voltage along with amp output. If their tester just gives a green light then they are "Clueless on Earth".
Can either you or hubby read wiring diagrams? Next step is to verify voltage to the field coil (sense voltage) at the alternator plug.
They should give you the output voltage along with amp output. If their tester just gives a green light then they are "Clueless on Earth".
Can either you or hubby read wiring diagrams? Next step is to verify voltage to the field coil (sense voltage) at the alternator plug.
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OK, update... Had the alternator tested at auto zone. Plugged the test unit into it an got a reading of 14.5 volts. Tests that battery, came back questionable. 1st test while truck was off read good at 12, good... started the truck for the second test came back reading 11.5, questionable... Bought a new battery, had good results for 2 days then the light was on again. Upon closer inspection found an idler/tensioner pully that was seized up, got new one and belt... Installing today. Posts about getting a belt diagram and any tips for this job on a new thread.
Sooo that's where we are right now.
Sooo that's where we are right now.
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stamp11127
Full Access Members
I've added a sticky in the electrical section titled "Battery 101" to guide you on the voltages you should be reading with a meter.
OK so according to what I gather from your post stamp my battery was only at 25%charge and below, ugh. How any the alternator test? What's the good range on that?
Got the pully and belt replaced, jumped the truck, within 2 minutes of taking the cables off it died, thought it was cold (below zero with wind chill last couple days), or gas lines, jumped again, with called still hooked up battery was reading 13.5 at the post, removed cables, checked battery, reading 7.5, so it's like we're not even taking a charge or maybe grounding it somewhere?... Idk... Thoughts maybe a broken wire somewhere, but not taking a charge at the post is concerning.
Thoughts?
Got the pully and belt replaced, jumped the truck, within 2 minutes of taking the cables off it died, thought it was cold (below zero with wind chill last couple days), or gas lines, jumped again, with called still hooked up battery was reading 13.5 at the post, removed cables, checked battery, reading 7.5, so it's like we're not even taking a charge or maybe grounding it somewhere?... Idk... Thoughts maybe a broken wire somewhere, but not taking a charge at the post is concerning.
Thoughts?
stamp11127
Full Access Members
Watch this from "Eric the Car Guy" and let me know if you have any questions.
https://www.youtube.com/watch?v=FTGz0PKIl84
https://www.youtube.com/watch?v=FTGz0PKIl84
Texpedition45
Full Access Members
This may sound stupid considering all of the work done so far, but hace you checked tour grounds? I had a weird intermittent issue with the charging system and electronics that ended up being a bad ground to the battery. One cable and terminal later, and it's been just fine.
Hey TeX, thanks for your input. We checked all the connections, cleaned some, made sure we had good contact, charged the battery to 12.9, sat overnight in minus 10° weather, stated right up this morning, gauge read on the high side of the half mark on the gauge, took it on the highway for about 20 miles, battery light on the whole time 
but no stall. Went shopping for an hour, came out, started right up, gauge still on the high side, got on the highway and the gauge started to drop like something was putting a hard draw on the battery, you could just watch it creep down. Never bottomed out tho and made it home... Hubby's thinking we've got a positive leg somewhere that's grounding out intermittently cause we're good for a while then we're blah... I don't even know where to start looking... Was thinking about bypassing the external voltage regulator but... I dunno... Thoughts?
but no stall. Went shopping for an hour, came out, started right up, gauge still on the high side, got on the highway and the gauge started to drop like something was putting a hard draw on the battery, you could just watch it creep down. Never bottomed out tho and made it home... Hubby's thinking we've got a positive leg somewhere that's grounding out intermittently cause we're good for a while then we're blah... I don't even know where to start looking... Was thinking about bypassing the external voltage regulator but... I dunno... Thoughts?
