charging problem?

[jaynes]

Hey guys, long time no talk. Had a few problems in the past. Anyway, the headlights and all lights actually, will dim at idle, and then when you push on the diesel to bring the rpm's up, they get brighter. The voltmeter shows the same thing on the dash. It goes down pretty darn low at idle, then goes up to normal when rpms are increased. Does this sound like an alternator problem? If so, where's the cheapest place to get an alternator, besides salvage yards (had no luck with those). Thanks!



jaynes

 

[Philip]

The problem your talking about is pretty much normal for a Dodge. The gassers do the samething.



As long as it comes back up after you give it some throttle. I wouldn't worry about. With all the lights on it is pulling around 30 amps. Most charging systems have problems supplying this amount of power at low engine speed.



If you normal driving is low speed at night then it might be an issue.



What is your idle RPM?

 

[jaynes]

I"m not sure what my idle rpm is, I don't have tach. I'd love a tach, though. This hasn't been a "normal" problem. It just started about a month ago. It's never done this before.



jaynes

 

[Philip]

With the age of our trucks you might have a set of brushes about worn out and not making good contact.





I normaly do most of my shopping at NAPA. There are stores nation wide so support on a failed part away from home can be had. I have used this a couple of times on the road. Stay away from autozone. I have seen to many of their starters and alt fail in 30 days or less. Thats if they work out of the box.



In the junkyards you might want to look for a bosch alt off of a middle 90's Dodge spirit. It uses a 6 grove alt just like our trucks. Do not use a 5 grove pulley alt. It has different mountings on it. The pulleys interchange. But the mounting points are different.

 

[jaynes]

Funny you should mention autozone...

Yeah, I wouldn't go to autozone to save my life. I bought a reman starter from them, cause mine went to heaven about a year ago, and I put it on, worked just fine... until cold weather operations. THe bendix gets really sticky and caught up when the cold weather hits. It'll engage for a second, then kickout halfway, making for a real nasty grinding sound. Sometime, It'll only engage halfway. Ticks me off that I have to replace that again before winter hits. . But what can you do. I was thinking about devising a high-idle mechanism. Got any ideas? I had a PTO cable in mind...



jaynes

 

[DGamelin]

You might check your battery if it is old, tired or to small, it may not have the amps to keep up with the draw. If the battery is strong when you shut off the truck it should hold the lights. A good starting truck will start on a tired battery in warm weather.



Dean 93 2wd stock 187k

 

[jaynes]

yeah, the battery is practially brand new. At idle, the lights dim to what they would be if the engine was off and the lights were on. It's like the alternator isn't there until the rpms come up.

 

[JLEONARD]

My lights, etc work just as good at idle as they do when I'm running.

My idle is about 725.

Jay

 

[jaynes]

So is my alternator going bad or something?

 

[KSommer]

So is my alternator going bad or something?

not necisarily, dodge has a tendancy to not make any power at idle. my old gasser didn't, with the stock alt, or with the autozone reman. maybey i'd worry about it if you leave it idle for hours on end, but otherwise, no, let it be.

kent

 

[JLEONARD]

or something?

I would not leave mine like that. I don't think it has to be that way.

Just think of wintertime... sitting at idle, headlights on, heater fan on high, and the wipers are on... barely moving.

That puts a lot of strain on motors and wiring when the voltage is so low that it slows things down.

I would fix mine if it were like that... but that's me.

Could be the alt, could be the regulator (I have the external type).

Jay

 

[jaynes]

hmmm

So what if it is the regulator. Is that separate from the alt? If it is, do I just test it with a regular ohm meter, or can I tell if it's the regulator without one. The alt isn't making any funny noises or anything, but if I could just replace the regulator instead of the alternator, that would be alot cheaper.



jaynes

 

[JLEONARD]

If its an early 91 the voltage regulator is seperate... it is a rectangular box on the firewall above/behind the engine.

They are somewhat notorious for going bad, but I'm not sure your symptoms are those of a bad regulator...

Hopefully someone better with electrics will jump in.

Jay

 

[GGott]

Funny thing happened on the way to the alternator shop... ... . you described what happened to me yesterday..... long & short of it-- A&B Alternator service in Nanaimo, B. C. ... removed my alternator, with 328k on it and original brushes (Nippondenso-120 amp) . . replaced the brushes, cleaned it up, and reinstalled it - $50. + tax..... boy was it raining ... ... I carry a spare voltage regulator... Greg

 

[DGamelin]

I just put brushes in mine a couple days ago. Mine stoped charging when I was down in TX. I hit it whith something and it started charging agin, so I new it needed brushes. It ether worked or it didnt. When I got back I got a set from the shop we get are alternator from $12. 50 fixed it right up. Buy a set there cheep enough. I asked about your truck, the first thing he said was raise the idle. If the trans files comfortable your fine. Most often that will do it. I looked up your truck, book says 750-800 with ac. I have mine at 800. The trucks idle sounds hi but works good.



93 2wd auto 187k

 

[jaynes]

Well thankyou very much Gamelin! Very informative. Are those brushes hard to install? Never done that before. I really wish I knew what my idle speed was. Is there any way I can figure that out? I had it set high one time, but that was for a different reason. Thanks alot guys!



jaynes

 

[DGamelin]

Thanks If yours is the same as mine a Nippondenso changing the brushes is a breeze. You don't even have to breake the alternator apart. Take the alternattor off. Set it on a bench with the back facing you. On the back of the alternator is a little tin shiled. Take the shiled off and the brushes are right there. The brushes are self contained. Three little philps screws holds them down. It would be best to buy the new ones first. Then you would see what they look like. After you take the old ones off, using a scotch bright pad wrap it around the armature were the brushes ride and spin the pully with your other hand to clean the contacts on the armature. They should be a nice shinny gold color. All your going to do is clean the carbon off of them, polish them. Do not use a coures sand paper of any kind. You'll see the new brushes are spring loaded. You'll have to compress them to put them on. That's it. While it's off and you are spining the armature make sure the bearings spin nice and smooth. The best way to set your idel is with the right tools. The way they do this is with a digital hand held tach. They put a sticker on your hermonic balencer. Point a laser tach at it and it gives a reading that quick. You could turn your idel up a little. Get in it and put in gear. If it doesn't feel like it's hits hard then you are probably alright. If you go to far when you put it in gear the truck will want to leap and you'll feel the trans hit to hard. But you should be able to go far enought to make you lights hold. I can't find the right words but I think you know what I mean. If it doesn't feel safe bake it down!



93 250 2WD 187K

 

[jaynes]

Thanks man, that's really helpful. I'm getting right on that this coming weekend. If I remember, I"ll post one back up to let you know how everything went. PS, do you know where to find tachs for our trucks? I would really like one. I looked and I can't find em anywhere! Maybe I'm blind...



jaynes

 

[Philip]

With your truck being a 91 it doesn't have the built in tach harness that the 92 and 93 models have. Auto Meter has a tach that hooks into the alt fields. There are a couple of members that use them. I hope they see this and post about them. I am not sure what Isspro has for a nontack wired truck.

 

[Paychk]

Isspro has the alternator tach as well a kit with magnets to glue to the front pulley.