Ok I have been having some odd issues the last few weeks.  About a year ago I got a hard CEL code P0123 and P0122.  I checked for AC Noise at the Alternator and got around .03 VAC so no problems there.  I swapped out the APPS for a TIMBO no problems truck runs fine.  Now a year later I get a random P0122, P01693 and another code I don’t remember it was int he 300s, the last few weeks....it comes and goes usually at startup during idle.  This morning I go to take the Wife last minute shopping and all of the sudden after startup I get an Air Bag Light and Brake light stuck on.  Also no power to the Heater Blower Motor.  Drive the truck about 10 miles or so everything else works.  Stop the truck turn it back on about 5 minutes later all is good no more lights blower is good.  Drove home popped the hood checked again for AC Noise getting .014 VAC at the Battery but I am now getting .045 to .09 VAC at the Alternator with random spikes they are fast spikes they don’t register for long but they go over .1 VAC.  I am thinking this is my issue causing odd things to happen.  Alternator is original on the truck around 270K miles.

 

First of all anyone have any thoughts on my issue or experienced the same thing?  Also am researching alternators bottom line is to make sure it does not have the AC problem as well so check it on the bench before buying is what I am getting.  Thanks for the replies.

Edited December 23, 20177 yr by deehammer
Grammar

We have diode packs for the denso alternators.

I think you might have two problems.

 

5 hours ago, deehammer said:

This morning I go to take the Wife last minute shopping and all of the sudden after startup I get an Air Bag Light and Brake light stuck on.  Also no power to the Heater Blower Motor.  Drive the truck about 10 miles or so everything else works.  Stop the truck turn it back on about 5 minutes later all is good no more lights blower is good. 

I think your ignition switch my not be fully returning to position II due to a sticking lock cylinder. The next time this happens rotate the ignition key slightly back, counterclockwise, and see if things change.

 

5 hours ago, deehammer said:

AC Noise getting .014 VAC at the Battery but I am now getting .045 to .09 VAC at the Alternator with random spikes they are fast spikes they don’t register for long but they go over .1 VAC.  I am thinking this is my issue causing odd things to happen.  Alternator is original on the truck around 270K miles.

Are your batteries in good condition, not to old or weak?  Make sure grounds are good and battery terminals are clean, tight and in good condition.    I was having high AC voltage, 0.05-0.1, and replaced the diodes and brushes.  Now the AC voltage is at .03.  

To update this thread I took out the Bosch Alternator (original) paid a local Alternator shop $129 to rebuild it.  They had it I don't the next day with a 2 year warranty.  I figured if it lasted this long it was a better to stick with the stock one rather than gamble with the local Part Store Chinese versions but time will tell I guess.  Re-installed almost 2 weeks ago all seems to be good.  A/C noise level is under control and so far (knock on wood) no more issues. 

I have decided though that I am going to spend $200 or so to build myself some brand new battery cables all the way around with the military style terminals.  Not something that I have to do but it is time after 19 years.

My opinion... I'm sure age plays a part, the service manual has pretty good info on testing cables.  

 

I was able to get some cables used from another member on here and being our cables are so long I was able to re-do cables on genny in  RV.   Generator in RV is not so particular as our 2nd gens elec wise.  Worked out good for both of us I think?

On 1/9/2018 at 1:09 PM, deehammer said:

I have decided though that I am going to spend $200 or so to build myself some brand new battery cables all the way around with the military style terminals.  Not something that I have to do but it is time after 19 years.

 

If you take care of the end you can have old cables that are new. Like I'm still running factory battery cables and never had to clean them once. They never corroded only removed the cables maybe a handful of times. But i'll have 20 year old battery cables that are absolutely fine. 

 

I'll ask a question. What is the only two materials that can hold sulphuric acid?

A: Glass and Plastic.

 

Q: What is plastic made from? 

A: Oil. So if you keep your teminal damp with engine oil they will never corrode. As for grease or terminal sprays are OK but also messy and could stain clothing. Where engine oil typically leave a light coating and terminal can't oxidize.

6 hours ago, Mopar1973Man said:

Q: What is plastic made from?

BPA that's why if anyone is using plastic food containers and microwaves their food in them especially liquid, that is known to cause cancer among other things. Same goes for other dishes and coffee cups. Use glass and stainless steel or ceramic,  you get the idea, same goes for beer in aluminum cans or pop, all this crap is killing us slowly, along with gmo's in foods and fluoride in water and toothpaste,  that is only slightly beneficial when it's in contact with the enamel itself and not consumed, when consumed it does major damage to lots things.

Sorry I had to. 

@Dieselfuture Focus... Keep your focus here.  

 

Different topic about BPA plastics and health issue. I'm taking about sulphric acid and what can contain it. Then giving an idea on how to protect battery terminals. 

I see, I'll just keep walking, too broke to pay attention