Voltage drop/complicated
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Lead Driver
Joined: Nov 2000
Posts: 6,646
Likes: 352
From: Albuquerque
Voltage drop/complicated
I have a radar detector that displays voltage now. don't know how long this has been going on but initially on starting I get 14.0v but after running for a while it starts to sag all the way down to 12.5v if I have load turned on. After a brief stop it goes back up to about 13.8v and begins to sag again. Very frustrating as I have a new red top battery old one did the same and 140a Power Master ( tried another exact model I happened to have on hand) one wire alternator. Large cables, lots of grounds, tight belt. Even with nothing else turned on it happens (MSD ignition box). Battery voltage after resting is stable at 12.72v which is good for the red top. Less that .5 ohm from alternator case to battery ground.
Power Master says the alternator cannot be remote referenced (ignition hot to terminal one I think) and idle voltage checked at idle is 14.8v. WTH! God must think I am Job's replacement with some of the oddball stuff I run into.
Gonna use a remote volt meter to compare actual battery volt to interior volts but I think it's only .4v less.
Anywho, help!!!!!!!!!!!
Power Master says the alternator cannot be remote referenced (ignition hot to terminal one I think) and idle voltage checked at idle is 14.8v. WTH! God must think I am Job's replacement with some of the oddball stuff I run into.
Gonna use a remote volt meter to compare actual battery volt to interior volts but I think it's only .4v less.
Anywho, help!!!!!!!!!!!
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Lead Driver
Joined: Nov 2000
Posts: 6,646
Likes: 352
From: Albuquerque
12.5v is enough to start the battery sulfacting. I don't think I should ever see less that 13.4.
Side note I'm checking belt tension. felt pretty tight but it's a big alternator.
after a hard launch the other day checking out new gear. I noticed some smoke coming out of the hood seams. Thought it weird the tire smoke got sucked up there. More likely the belt was slipping I guess.
I'll be back.
Ivan Toratireoff
Side note I'm checking belt tension. felt pretty tight but it's a big alternator.
after a hard launch the other day checking out new gear. I noticed some smoke coming out of the hood seams. Thought it weird the tire smoke got sucked up there. More likely the belt was slipping I guess.
I'll be back.
Ivan Toratireoff
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Lead Driver
Joined: Nov 2000
Posts: 6,646
Likes: 352
From: Albuquerque
There is nothing normal about my voltage fluxuations. Anythin lower than about 13v indicates a problem It appears that the belt was slipping. Waiting on a new Gates. It seemed tight but I guess not tight enough for a 140a alternator.
Lead Driver
Joined: Oct 2018
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Cargo Master
Joined: Mar 2008
Posts: 2,577
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From: Washington
If you went with the 3G alternator, instead of a one wire, you won't be having this issue.
But to be fair, I am not a fan of wire alternators.
Jim
But to be fair, I am not a fan of wire alternators.
Jim
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Lead Driver
Joined: Jul 2017
Posts: 9,616
Likes: 1,185
From: San Jose, CA
I use either dual v-belts, or serpentine setups on anything over 100a myself. Heck, even over 70a in my case! Especially the Ford stuff.
My large case 70a 1G alternator would squeal like a big dog until I upgraded to dual belts. All good after that, and I liked having the automatically deployed spare!
I don't think we see as much slippage on converted GM type alternators as we do on Fords, but that could just be coincidences and I just never noted the problems with others.
Your 140a model is a converted GM/Delco unit? The output number sounds familiar along those lines.
AS soon as I traded up to a 70a 1G alternator in my Bronco and started having belt squealing issues, I went with a dual v-belt setup.
Got tired of the noise and had it dealt with that same week.
My 130a 4G on the other hand, was already set up with a serpentine drive belt that was part of the Explorer accessory drive system.
Those with big output Ford alternators tend to have belt squeal with V-belt configurations.
Paul
My large case 70a 1G alternator would squeal like a big dog until I upgraded to dual belts. All good after that, and I liked having the automatically deployed spare!
I don't think we see as much slippage on converted GM type alternators as we do on Fords, but that could just be coincidences and I just never noted the problems with others.
Your 140a model is a converted GM/Delco unit? The output number sounds familiar along those lines.
AS soon as I traded up to a 70a 1G alternator in my Bronco and started having belt squealing issues, I went with a dual v-belt setup.
Got tired of the noise and had it dealt with that same week.
My 130a 4G on the other hand, was already set up with a serpentine drive belt that was part of the Explorer accessory drive system.
Those with big output Ford alternators tend to have belt squeal with V-belt configurations.
Paul
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