Alternaror noise test article

[GSP7]

I am searching for Moparman's Alternator "noise" test article. Cant find where it is. I want to check and see if my alternator is 100% or not

 

Does Alt noise have to do with a bad diode? I saw a Alternator part on Larry Bs sight. (Diode pack / Rectifier Bridge for Deanso Alternator)

Is that "the fix" if your Alternator is making "noise"

 

I think I checked my alt a few years ago, before I replaced my TPS

 

Rick

Edited March 25, 2015 by GSP7

[War Eagle]

I think this one might be what you are looking for.

 

http://forum.mopar1973man.com/index.php?/topic/9004-replacement-alternator/

[GSP7]

That was a thread

 

I thought there was a article/ write up on how to test a Denso Alternator for "noise" or a bad diode

 

I clicked the "Article" button at top of this page but didnt find a alternator test article

 

 

.

[TFaoro]

Here's the two videos. I just hook the positive lead to the positive stud on the back of the alternator and the negative to the passenger battery terminal.

https://www.youtube.com/watch?v=UveGtGuswBw

https://www.youtube.com/watch?v=s6w0WF5wr2g

[Mopar1973Man]

Here is the article...

http://articles.mopar1973man.com/2nd-generation-24v-dodge-cummins/28-transmission-systems/260-torque-converter-lock-unlock-issues

[GSP7]

Why did you take the big fuse out?

 

I have a small volt meter that has the plug in needles.  Are you just going from Testing DC and then testing at AC

 

What will it read at AC if you have a damaged diode?  Will it read 14 volts also just like hooked up DC

Edited March 25, 2015 by GSP7

[Cowboy]

The Big fuse connects the battery to the alternator.  By removing it you keep any AC signal made from the alt from getting to the battery or any other computers in the truck and causing the issues.

 

Yes, an AC signal coming from the alt is caused by a leaky/defective Diode.  

[Mopar1973Man]

Why did you take the big fuse out?

 

System isolation. If the field wiring and the charge lead is disconnected there should be near zero or zero AC noise.

 

What will it read at AC if you have a damaged diode?

 

Normal alternator is 0.01 to 0.02 Volts AC

 

Marginal alternator is 0.05 to 0.09 AC Volts

 

FAILED alternator is any voltage above 0.1 AC Volts.

[GSP7]

Where did you buy your test meter?  My two small meters arent for automotive

 

My goal is to make sure my alternator is ok. To protect my ECM.

 

I read that bad alternator diode causing alternator noise can harm the ECM, If that is true

Edited March 25, 2015 by GSP7

[TFaoro]

Where did you buy your test meter?  My two small meters arent for automotive

 

My goal is to make sure my alternator is ok. To protect my ECM.

 

I read that bad alternator diode causing alternator noise can harm the ECM, If that is true

Not only the ECM, but it can also harm the PSG on the top of the injection pump! 

[Mopar1973Man]

Where did you buy your test meter?  My two small meters arent for automotive

 

My goal is to make sure my alternator is ok. To protect my ECM.

 

I read that bad alternator diode causing alternator noise can harm the ECM, If that is true

 

 

Not only the ECM, but it can also harm the PSG on the top of the injection pump! 

 

Actually anything electronic right down to your cell phone plugged into the power point charging, GPS hanging off the windshield, to maybe you stereo in your dash. So anything electronic hooked up to the electrical system of the truck can and will be affected by the AC noise produced by bad diodes.

[GSP7]

Where did you buy your test meter and what brand/kind  is it?

[TFaoro]

Borrowed a fluke meter from a friend. Mike?

[Mopar1973Man]

Old Fluke 75 DVM...

[GSP7]

Is this test procedure explained in my big 2 book service manual ?

Edited March 26, 2015 by GSP7

[GSP7]

When using the multimeter to check DC and then AC, should the big fuse be removed to get a proper AC reading?

 

I still get 14 volts on AC.  I dont have a  dial on my meter. You have to put the pin in the AC hole on the meter.  Im using a cheap old needle type volt meter. (not digital) and its not detailed enough to even read .1 or .01 or .001.  This meter is probably 40 years old.

[Mopar1973Man]

Time to update to a new DVM (Digital Volt Meter). Alternator AC power is variable AC frequency that changes with RPM. So you can't buy a cheap hardware store meter for household 60 Hz. It has to be able to measure variable frequency.

 

https://www.youtube.com/watch?v=MGaHaIXZioA

[GSP7]

Does the big fuse need to be removed to get a proper AC reading?

 

Is this test procedure explained in my big 2 book service manual ?

Edited March 26, 2015 by GSP7

[TFaoro]

Does the big fuse need to be removed to get a proper AC reading?

 

Is this test procedure explained in my big 2 book service manual ?

No

No

 

This isn't an issue dodge foresaw, so it won't be in the manual. You only remove the fuse to see if that is the reason for torque converter lock/unlock issues. 

It's really easy to do. Get a high quality meter, set it to V~ or Vac (Whichever your meter has.) Then start the truck and put a lead on each of the driver side battery posts. 

[GSP7]

No

No

 

This isn't an issue dodge foresaw, so it won't be in the manual. You only remove the fuse to see if that is the reason for torque converter lock/unlock issues. 

It's really easy to do. Get a high quality meter, set it to V~ or Vac (Whichever your meter has.) Then start the truck and put a lead on each of the driver side battery posts. 

Thank you ,  Yeah , Im online looking for a Good multimeter. I found a old new in box Fluke 85 like in the video on ebay 6d bid wait.

 

Is that fluke 85 kinda outdated not able to do modern auto computer tests, like that last diode test video? That snap-on tester is probably $1000+ scope/meter Id guess

 

  Also looked on line at some of napa's, o'riely's, autozone's but they might just have cheap junk in their stores

 

Can you guys refer me to a good Digital Volt Meter for testing my truck that wont break the bank?    I saw some for $300-500+++

 

Rick

Edited March 26, 2015 by GSP7