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Old Nov 1, 2018 | 01:49 PM
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Eletrical problem

My batteries have been draining. I'm not sure what it is. I repaired some wires when the truck was apart but that was simple cut and heat shrink to fix the exposed wire and reattach wires that broke in half. I added a set of lights in the bed LED and the run off of a relay. I need to check to see of the relay is not wired up correctly. The lights work fine and there is a fuse too so I don't think that is the issue. I could have miss wired the starter relay on the fender. Anyone have a pic of how it is wired up? I looked on the net and found many but not an exact. I use a test light to see of there is a draw on the battery and the test light just barely comes on a low glow. It could be the batteries but i just don't think so they are 10 months old but have died 2 times completely since I put the truck back together.
 
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Old Nov 1, 2018 | 02:04 PM
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Not a great picture but I have this one. Basically the big lug in front has all the connections and the rear big bolt just goes to the main starter solenoid. The wire unplugged is the key to start terminal for the relay

 
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Old Nov 1, 2018 | 02:08 PM
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That is what I have, all wires on 1 lug, the starter wire on the other and the ignition wire or trigger wire. my batteries were 12.45 v last night and were 11.7 this am. with the batts disconnected they stayed at 12.45 for 2 days. I don't see a reason and the fuses are good. no smoke. maybe the relay some how?
 
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Old Nov 1, 2018 | 02:09 PM
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I will isolate the alt, starter and the relay and see what happens.
 
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Old Nov 1, 2018 | 03:13 PM
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I have fixed a few vehicles, GM mostly, with alternators that drain as the wiring was reversed. It was essentially still 'on' This was as their two wire plug was worn out and the locater tab broken off. 3Gs are nearly impossible to wire up wrong.

Have you done an amp draw test? Do it, leave meter on there, start by unplugging alternator. Then go to the fuses, one by one.

It could be just the glove box light.
 
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Old Nov 1, 2018 | 03:19 PM
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Originally Posted by Hit Man X
I have fixed a few vehicles, GM mostly, with alternators that drain as the wiring was reversed. It was essentially still 'on' This was as their two wire plug was worn out and the locater tab broken off. 3Gs are nearly impossible to wire up wrong.

Have you done an amp draw test? Do it, leave meter on there, start by unplugging alternator. Then go to the fuses, one by one.

It could be just the glove box light.
Oh crap! I forgot that stupid light did this to me a year ago. I thought I replaced it with a LED but may not have. Thank you.
 
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Old Nov 1, 2018 | 03:47 PM
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Originally Posted by mcali2
Oh crap! I forgot that stupid light did this to me a year ago. I thought I replaced it with a LED but may not have. Thank you.
got me as well

I just went through battery drain on my nephews car.
Hooked a fluke meter inline of battery + cable and started to yank fuses and found a stereo pre-amp drawing 2 amps with car shut off.

You will blow a test meters 10 amp fuse if GPs get energized or bowl heater is connected.
 
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Old Nov 1, 2018 | 08:25 PM
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I have had batteries that hold over 13V overnight. A good battery should hold more than 12.6 for days. 12.8 is a good number, 12.4 is not holding anywhere near capacity. Do the whole routine, clean terminals, clean, water and charge batteries, check grounds and load test the batteries individually. This is a PITA with diesels, no tolerance with voltage issues. We probably all need to do this every year, tis the season.

My alternator runs 14.7V

Glovebox light? Who would guess? They say you never see the one that gets you.
 
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Old Nov 1, 2018 | 09:44 PM
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I had a trunk light in a BMW...talk about never seeing it.
 
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Old Nov 2, 2018 | 08:31 AM
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I say under charged batteries or they are getting weak

good read on state of charge
https://batteryuniversity.com/index....tate_of_charge
 
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Old Nov 2, 2018 | 07:10 PM
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is this on the 97?
feel the alternator after sitting over night. if one of the diodes in the regulator goes bad, it will still charge the batteries, but when shut off cause a parasitic drain that will kill the batteries in two or three days.
when the diode goes bad the alternator will be hot to the touch overnight.
 
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Old Nov 2, 2018 | 10:01 PM
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Update. I was not able to find any power draw that would make the meter charge. I charged it all day and night, it hit 12.95 and quickly went to 12.35. in the morning it was 11.87 and when it warmed up was back to 12.34. I replaced the Batteries as they were 10 months old. It was free. I guess I will see if they don't hold.
 
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Old Nov 5, 2018 | 09:14 AM
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you have a bad battery and it is taking both batteries down, voltage should not drop that fast
 
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Old Nov 5, 2018 | 11:57 AM
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It seems to be good now but still have to try starting a few times in the cold. Must be a GP issue? they are what 2 or 3 years old but the truck is not used much. What kind of life do they have? I'm not clear on how to test them. I have read about it but still not clear.
 
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Old Nov 5, 2018 | 12:49 PM
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glow plugs? mine are now 16 years old and still work fine.
 
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