Montana charging system Problem

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Battery light is on dash. Got new battery, cleaned & tightened terminals. 12 V on battery & Only 12V at main red wire at alternator. Took out alternator. Tested good at 130 amps. Put back in. Same problem. What should the voltages be on the small 2 wires on the alternator plug ?? Thx
 
with key on should have 12+ volts at both wires on the two wire plug with the plug connected. The wires in the connector often break
 
Are your battery cables look rust and original never changed? You must change new ones, for it you need ramps, also clean round connectors at the starter
 
thundercat said:
Are your battery cables look rust and original never changed? You must change new ones, for it you need ramps, also clean round connectors at the starter
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wiring diagram ?
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the previous post is referring to the positive battery cable connection at the starter and the negative battery cable to it's ground location. Did you test the two alternator wires for voltage?
 
melsg5 said:
the previous post is referring to the positive battery cable connection at the starter and the negative battery cable to it's ground location. Did you test the two alternator wires for voltage?
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With the key to the on, & the engine running @ Either low or hi idle with fans & lights drawing power - there is only about a volt at the small orange wire. That is the turn on signal for the alternator. The gray wire in the same plug never has any voltage. It is the field duty cycle signal. I have an Alldata diagram but it doesn't really help. Still Not charging. Please help. Thx
 
stick something metallic and sharp into the grey wire to pierce the insulation a couple of inches back from the plug to see if the wire has power but the plug connection is bad.
 
I had also previously untaped part of the harness where the orange & grey wires run to plug J2 into the computer box in the air filter housing. With the battery undone I used a good Fluke ohmmeter & on the Front side of the J2 plug & the alternator plug I got a proper 0.5 ohms for each wire. Also moved the plugs around & the readings were good. Wires looked good. With battery plugged in & J2 still off there is about 8 volts at the 45 ( grey ) & 53 (orange ) pins. When I undo battery, plug it back in, reconnect J2 & turn key back to on there is no voltage - probably because other circuits are now connected. A cheap scan tool will allow me to erase the battery light but only for 5 sec. Then reappears. No codes come up. No gain in alt output for these 5 sec either. also checked all fuses & swapped relays in dash & above battery fuse area. Cleaned ok looking fender ground. Anyway I'm still nowhere really so please keep trying to help me Thx
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melsg5 said:
stick something metallic and sharp into the grey wire to pierce the insulation a couple of inches back from the plug to see if the wire has power but the plug connection is bad.[/QUOTE. I had previously untaped part of the harness where the orange & grey alternator wires go to. I measered 0.5 ohms on the Front side of the J2 plug where they go to the Front side of the alternator plug. J2 is in the computer box in the air filter housing. Also wiggled plugs around & wires are good.
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Also pins 45 & 53 for the orange & grey wires where J2 plugs in have about 8 volts there when the key is on. No voltage right behind or at alt plug with a good connection when J2 is reattached & key on. Poss because other circuits are connected now though. I can hit erase on a cheap scan tool & battery light goes out for 5 sec. Reappears though. Tried 3 X. No alt gain at battery wire. Checked all fuses & swapped relays in dash & above battery area. Cleaned fender ground. Anyway, Battery light is still on. Please keep trying to help. Thx
 
what year and which engine do you have?
 
The van is a 2006 Pontiac Montana with a 3.5 L/ V6.
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Still Not charging after I tried all these tests as they specified ...
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I checked again for anything related. I then decided to put in another alt in case something didn't work out during the testing of the orig alt. So now it is all working again
 
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