Change BLK/OR wire from alternator

[mistert2]

I am having an issue with NEW (3rd) alternator not charging. I have checked ALL fuses, ok. So I am checking all connections. Only one I cannot get to is this BLK/OR cable from B+ on alternator to engine blk. The connection is on top of engine next to thermostat housing. I cannot get in there without taking these out and checking. Is it possible even to tighten there? Can I bypass this and connect somewhere else?

You guys have helped me alot and I thank you, but this one is HUH. HELP please.

 

[koda2000]

if it goes from the alternator to the engine block (i assume that's what "engine blk" means) then yes, you can connect it anywhere on the engine block as long as it's metal.

 

[mistert2]

Thanks koda2000

 

[koda2000]

according to the wiring diagram, this is not a ground wire (blk/org from alternator). it looks like it goes to the power distribution box.

just a suggestion... stop starting new threads on the same problem. it makes it hard to follow.

 

[mistert2]

Sorrry. Some are new problems from old issues. Thought best way to address. Thanks for the help.

 

[mistert2]

Just checked the 175amp mega fuse and shows continuity. (maybe stupid question but) Does that indicate fuse is ok?

 

[com4tably.numb]

usually yes

 

[budwich]

simplest way to find your problem is to disconnect ALL wires going to your alternator (at the alternator). Then, at each wire, check what the voltage readings are (with respect to a KNOWN ground). Do this with the key OFF and the truck NOT running. The result will readily tell you where your issue is IF it is in your WIRING. You can go from there.

PS. This has been solved on this forum before IF you follow "suggestions".

 

[albi1cnobi1]

Been trying to walk him through this on the other 2 threads about this problem. mistert2, you can disconnect that wire. It goes from the 175 amp fuse to the alt. pick up a cheap cable from the parts store that is long enough to reach safely and hook it up temporarily and see if that works. From what you described before your voltage is o.k. at the 175 amp fuse and low at the alt. This test will confirm or rule out a problem with the blk/or wire. Just be careful with the old one that it doesn't short out.

 

[budwich]

But it either a problem or it's not... just replacing things probably isn't going to get you there. Do the checks I suggested. Good luck ... the other recent post DID NOT follow thru with the checks and paid $125 (lucky) to find a wiring issue that he basically already had found with the checks.

 

[albi1cnobi1]

simplest way to find your problem is to disconnect ALL wires going to your alternator. Then, at each wire, check what the voltage readings are (with respect to a KNOWN gorund). Do this with the key OFF and the truck NOT running. The result will readily tell you where your issue is IF it is in your WIRING. You can go from there.

PS. This has been solved on this forum before IF you follow "suggestions".

I went through this with the OP in his other thread. Had him check voltages at various points in the wiring. From what I can gather from his checks, he has 12v at the fuse end of the blk/or wire and less than 9v at the alt end.

 

[budwich]

The measurement seems suspect, but hey it's the internet, not actually there.

 

[albi1cnobi1]

Yeah, don't think he was real sure of his readings.

 

[mistert2]

Thanks guys for help so far.
I just checked volt with new voltmeter
battery is @ 12.8v drops a little while engine runs but holds @ 12.4+-v
B+ alt to distribution box 11.4v engine off and on doesn't change
checked Blk/OR wire from B+ to dist box w/old wire and new wire same no difference 11.4v
Checked alt plug and get continuity w/grnd assume ok
checked volt from yellow/white wire and get 11.4v
What else can I check?

 

[koda2000]

i may be getting my threads mixed up, but it's worth asking again... is your BATT light on with the engine running? does it light up when you turn the key to the ON position (bulb check)?

you should see around 12.6 volts at the battery with engine off (13'ish volts ok). with engine running you should be seeing 13.5 - 14.6 volts at the battery.

what continues to bother me about this problem is that it all began after changing the starter motor. can one of you guys post a wiring diagram showing the starter?

 

[mistert2]

Engine light is on with engine running
12.8v with eng off
12.4- engine on

 

[koda2000]

Engine light is on with engine running
12.8v with eng off
12.4- engine on

check engine light or BATT light on?

12.8v at the battery, with engine off, is very good (12.6 indicates a fully charged battery). 12.4 with engine running is low, but not low enough to indicate NO charging is taking place.

 

[mistert2]

Sorry battery light is on. Chk engine light off
Battery is brand new
BUT brand new (3rd) alternator is only putting out 11.4 volts
checked all connections and fuses and wires and ok

 

[koda2000]

do you have a set of jumper cables? if so, try connecting one lead to the battery negative terminal and the other end to the alternator's metal housing and see if that makes any difference to the voltage.

you might also try using the jumper cable to connect the large output lug on the alternator to the positive terminal on the battery and then measure volts... BE VERY CAREFUL not to touch anything else with the positive side jumper cable.

 

[koda2000]

curious. did you review the charging system wiring diagram that someone had supplied?