I know this topic is posted all the time and Ive gone through the other threads quite extensively and still havent been able to fix my issue.

As usual, replaced an old alternator and the new one didnt charge properly. Didnt have any other issues and the truck still ran fine. Every once and a while the brake light and charge light on the dash would flash for a bit. The major difference between my issue and the other charge issues Ive read on the forum is my charging is inconsistent. The gauge will read full charge for a while, then drop down for a while and repeat. Some days when I start the car the charge light will be on, some days it wont. The funny thing Ive noticed is that if the car has been sitting in the sun all day it will start and not charge well, if its in the shade or its cool it will charge fine and wait to heat up before having the issue.

Anyways, any further insight would be great. I despise working on electric, and in attempting to fix it Im pretty sure Ive blown something in my cb, but Ill post that as a separate topic.

 

So you put a multi meter on the battery while running and the voltage is between 13.8 and 14.4? id check it while the lights off and working fine and when its on and not working properly.Just because you got it from the parts store new doesnt mean they are good. I think all are remans and can have problems. Extreme temperature can effect the batteries behavior, but seeing as your location says vancouver I would eliminate that possibility, weathers been pretty mild here on the b.c coast. If you have a good multimeter, load tester, charger you could eliminate that, or take it to canadian tire and get them to check it. If not that, someone more knowledgeable will have to chip in.

 

Ive put a multimeter to it, but it wasnt very good, the readings where fairly off. But what I did notice is the the voltage read the same with the truck running and not running when it was having the issue. When it wasnt having the issue there was a voltage increase. (Ill grab a better one from work and get on testing it again).

The problem with working on it now and Im not necessarily attributing this to the fall weather. But the issue is far less persistent than it was in August. I now only see it after 2-3 hrs of solid driving, where as before it was around 70% of the time when I was driving. (bit of an annoyance to only be able to test it after so much driving)

I had the battery tested by a shop and they said it is on its last legs, but they recommended I clean up the battery a bit more and take it back. Cleaned, but my scheduled prevented me getting it tested again, Ill do that asap!

 

Just a thought but a bad bearing in the alternator that puts more drag as it heats up??

A belt that is just a little loose and with the heat it starts to slip more.

The wire coming off the B terminal of the alternator is old burnt and brittle as it heats up the ability to conduct goes down.

As your battery is on it`s last legs that might be part of the problem.

loose connection that gets worse when hot due to the arcing.


Have you updated your ground cables and the positive cable to the starter.

 

Ya I thought the loose belt was the issue originally, but I check it and the belt doesnt squeal so eliminated that issue. As for the bearing, my thoughts are, if that was the issue it would be fixed with the changed alternator.

Ill give the wiring another go through and check it out. Im not the most knowledgable with vehicle electronics, but what effect world the positive cable on the starter have?

 

I have had loose belts that never squealed just slipped.

With the quality of reman alternators you may have got a bad one it does happen all to often.

 

When you do clean your battery again, clean the top off with a little bit of baking soda and wet rag.Just try to keep it away from the service caps. It will neutralize the electrolyte, u actually get alot of surface voltage loss across the top of the battery from previously spilt electrolyte. Sounds like the alternator though if you tested it with the multi meter and the readings were appropriate. As said above, belt wont always squeel. If not your gona need to check the wiring.

 

Well, I definitely fooled myself into thinking I had fixed this issue.... Sorry for the lack of update, but I replaced the battery and the issue subsided. I sadly didnt take into account that I replaced the battery at the same time the cold weather arrived around here. Now that its warmed back up, the issue is present again.

Next step, recheck all the fuses, then the bearing in the alternator, then the belt tension and finally Ill move to the dreaded wiring. Any recommendations with were to start checking regarding the wiring?

 

I think I'm having the same issue. My brake and battery light flashed for a second 2 separate times last night. This morning is hesitated to start then an hour later it wouldn't start. Got a jump and ran to the auto parts store and got the battery tested. The results were needs charge. So again I got a jump so I could get home. On the way home cd player lights turn signal and pretty much everything electrical quit working but the truck ran fine. It's about 94 degrees here in Kentucky if that means anything. Any help guys?

 

They tested the battery but not the alternator?? Break out the Multimeter

Check the belt tension

Look at the battery terminals when where they cleaned last??

All the cables can get brittle and burnt with age as they do the lose the ability to conduct like when they were new.

The wire coming off the alternator B terminal is good for this.

I have also seen the plug in the alternator corroded .

 

Don't have a multimeter. Everything you listed looks good. Pulling the alternator as we speak. Starting a new job Tuesday so we gotta do this ASAP!!!

 

Alright pulled the the alternator. As I took it off I noticed there wasn't a bolt securing it on the top end. Maybe that was my problem considering it would possibly take tension off the belt? Btw this is a 86 22R straight axle pickup.

 

Well that would indeed cause a possible no charge issue.

replace the bolt M8x1.25

Tension the belt correct then see if that fixes the problem.

 

Sounds pretty much the same to me. The only difference is mine will start charging again a while after this issue first presents itself. Im going to be tearing into this on the weekend.

How would you recommend getting the proper tension on the belt? Without a tensioner that is?

 

Well got the alternator tested twice. Passed both times. Gonna slap it back on. Went and got a m7x1.00 bolt to make sure I'm more secure and tighter this time

 

It has been awhile since I changed belts but I use a pry bar being careful to hold tension on the alternator while I tighten the bolts.

 

Just did it. Had my dad put pressure on the pry bar while I tightened. It's all the way over and secure. Much tighter fit this time. Gonna grab a jump and see what happens. Stay tuned

 

Boom! Took a 15 min ride turned it off and it fired right back up. So to recap... my brake and battery light flashed a few times. then it wouldnt start without a jump. drained the coolant so i could remove a hose to make the the alternator easier. unhooked the - cable on the battery unhooked both plugs on the alternator. removed the bottom bolt on the alternator. In my case I didn't have a top bolt so I bought a m7x1.00 to replace. Tested the alternator which came back good. Put the alternator back on starting with the bottom bolt then put the top bolt on then lined the belt back on all the pulleys and had someone pry the alternator to make it tighter on the belt while it tightened the top and bottom bolts. Put the coolant hose back on the bottomside, refilled the raidiator and hooked the battery back up. Got a jump, took it for a spin and its all good from there. So moral of the story check your belt tension. If you can move it with your hand its too loose.

 

Awesome, glad that worked out. I do have the bolt securing the top end though and I originally tightened it using a pry bar so I question whether thats my issue... Updates will follow

 

Ugh!! Heres what i did this weekend to try and fix the issue, but sadly it did not work...

- replaced the alternator, because the bearing wasnt sounding good
- checked all the fuses in the truck
- replaced the belt as it was cracking and falling apart
- checked the wires coming from the alternator, including the ground and they are all crack and corrosion free.

Im at a complete loss at this point... Should I look into replacing the battery cables, although Im not sure how that would help...