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01-24-2022, 04:55 PM | #26 |
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Re: Vacuum erratic when electric fans turn on
Thank you. Yes I have an aftermarket wiring harness
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01-24-2022, 11:12 PM | #27 |
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Re: Vacuum erratic when electric fans turn on
So I looked though my old paper work. And this is the alternator that I have and this is the installation manual from powermaster. I was looking on the mad electrical website and it looks like this is the wiring harness that I need.
http://www.madelectrical.com/catalog/alt-1.shtml |
01-24-2022, 11:55 PM | #28 |
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Re: Vacuum erratic when electric fans turn on
Just ensure post 2 is connected far from the alt, nearest the battery. Not to the battery charge post on the rear of the alternator.
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01-25-2022, 12:32 AM | #29 |
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Re: Vacuum erratic when electric fans turn on
My plan is to order the harness from mad and use their instructions.
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01-25-2022, 12:35 AM | #30 |
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Re: Vacuum erratic when electric fans turn on
I am still wondering if this problem could cause my engine to intermittently stumble during acceleration.
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01-25-2022, 02:21 AM | #31 |
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Re: Vacuum erratic when electric fans turn on
Besides the vacuum dropping and the gauge needle bouncing around, does the idle speed change as well?
Figure out the low voltage problem first and see what happens then.
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Bob 1967 2wd Burb, 350/TH350, 3.73 posi Last edited by 67 Burb; 01-25-2022 at 02:33 AM. |
01-25-2022, 11:45 AM | #32 |
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Re: Vacuum erratic when electric fans turn on
I will take a look but it doesn't seem like the idle speed changes. But I have not checked it by looking at the gauge.
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01-25-2022, 11:48 AM | #33 |
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Re: Vacuum erratic when electric fans turn on
I got an email saying that 67 Burb posted a longer reply than the one he did in post 31 but it has disappeared. Was it removed or edited or something?
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01-25-2022, 12:40 PM | #34 | |
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Re: Vacuum erratic when electric fans turn on
Quote:
So has it been established that you do not have a one-wire alternator?
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01-25-2022, 12:44 PM | #35 | |
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Re: Vacuum erratic when electric fans turn on
Quote:
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01-25-2022, 01:20 PM | #36 |
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Re: Vacuum erratic when electric fans turn on
OK, that's good to know. What my concern was, that you were measuring 12 volts at the distributor. With the engine running, you should be getting a higher reading, in a range of 13.5 to 14.5 volts. also check voltage at the BAT connection on the back of the alternator.
Some one-wire alternators will not put out any current after the engine is started and then just running at an idle and need to be revved up before they "kick in", so after reading the voltage after starting the engine, rev to 2000 or 3000 RPM and check the voltage again. I have a one-wire alternator on one of my cars, and I had to rev the snot out of it to get the thing to charge. I ended up installing a smaller diameter pulley. You probably haven't noticed any problem with the battery keeping charged because once you start driving the alt kicks in. I feel that somehow this situation is caused by the low voltage you are seeing at an idle.
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01-25-2022, 04:33 PM | #37 | |
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Re: Vacuum erratic when electric fans turn on
Quote:
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01-25-2022, 09:06 PM | #38 |
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Re: Vacuum erratic when electric fans turn on
So I took some more readings after reving it up to 3000 rpm with the engine still running.
12 volts at distributor. 12 volts at alternator post. 12 volts at battery. In 2019 when I took readings with the same one wire alternator it tested. Checked battery while not running. 12.7 volts at the battery 12.7 volts at the starter 12.7 volts where the ground attaches to the block Checked battery while running 14.4 volts at the battery Checked battery while cranking It went down to 11.4 volts. |
01-25-2022, 09:24 PM | #39 |
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Re: Vacuum erratic when electric fans turn on
So I was thinking could it be that using the one wire alternator for the last 3 years has weakened my battery? Even in 2019 when I took those readings I was still having problems with the engine stuttering during acceleration.
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01-25-2022, 09:39 PM | #40 |
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Re: Vacuum erratic when electric fans turn on
Sounds like your alternator has a problem.
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01-25-2022, 09:43 PM | #41 |
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Re: Vacuum erratic when electric fans turn on
Do you mean the alternator itself or the way it is wired?
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01-25-2022, 09:58 PM | #42 |
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Re: Vacuum erratic when electric fans turn on
Hard to say. You need to find someone who knows his (or her) way around the wiring system.
If I was just down the street, I'd be there in a minute. I just checked our weather here and it's -29°C (-20°F), I'd much rather be in Burbank. But Brandon, Manitoba is a long way from Burbank, CA.
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01-25-2022, 10:31 PM | #43 |
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Re: Vacuum erratic when electric fans turn on
I guess getting the alternator and the battery tested would be a good first step.
It was around 75 yesterday. We get excited when ice forms on the car window overnight. I can’t even imagine what anything below 0 feels like Last edited by forestb; 01-26-2022 at 12:13 AM. |
01-26-2022, 09:31 PM | #44 |
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Re: Vacuum erratic when electric fans turn on
It looks like my battery is around 3.5 years old. I wonder if that could be my problem. I should have it tested.
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01-27-2022, 07:38 PM | #45 |
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Re: Vacuum erratic when electric fans turn on
One wire alternators require a large, at least 6 gauge, output wire to be able to respond to the load effectively.
If you're using the factory output wire it's way too small
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01-27-2022, 09:06 PM | #46 |
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Re: Vacuum erratic when electric fans turn on
It is a fairly thick wire I am not sure of the gauge but it is around 3/8 in thick including the coating.
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01-27-2022, 09:10 PM | #47 |
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Re: Vacuum erratic when electric fans turn on
What is interesting is that I am getting around 14 volts at my Voltmeter gauge
Last edited by forestb; 01-27-2022 at 09:17 PM. |
01-28-2022, 04:34 PM | #48 | |
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Re: Vacuum erratic when electric fans turn on
Quote:
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01-30-2022, 12:20 AM | #49 | |
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Re: Vacuum erratic when electric fans turn on
Quote:
experience with those one wire alternators, and personally, I wouldn't put one on anything I own. Having said that, I don't see how a one wire unit can be also wired up three wire.. The voltage sensing is done internally. And that would have to be converted by installing a conventional "3 wire" voltage regulator. Also, it's not a good idea to depend solely on the in dash volt meter. They are notoriously famous for their inaccuracy. Use a DVM for taking voltage readings.. |
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01-30-2022, 01:08 AM | #50 |
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Re: Vacuum erratic when electric fans turn on
All that I know is that I used the alternator as a 3 wire when I first bought it in 2009. I then started using it as a one wire around 4 years ago. When I was running it as a 3 wire I had removed the external regulator and put an adapter on on the plug that used to plug into the regulator that rerouted those wires.
I do understand that the voltmeters are not vary accurate. What is a DMV? I had the battery checked today and it was still in good condition. I took the alternator to get tested but they could not figure out how to hook there Machene up to it. I did notice that when I reinstalled my battery that positive battery cable sparked a little when it touched the post. I have heard that this might mean that I have a ground problem. Also maybe I just need a new alternator sense mine is now 13 years old. |
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