no charge and lights dim...

[jaynes]

I think I've posted this before, but now its becoming a pain in the *****. I'm reading little to no charge on the voltmeter on the dash, and my lights are really dim, just like when you have them on and the engine isn't running. Before, they would only be like that idle speed, and would start charging and get brighter when I increased the engine speed. Now it's not doing anything. Could this be a voltage regulator problem, or does it sound more like a bad alternator? If it is the volt. regulator, where is it and what does it look like?



Thanks!

Josh

 

[cerberusiam]

You should have the old style system with an external regulator. If that is true there should be a rectangular box in the middle of the firewall above the engine with a three wire connector. Thats the voltage regulator. If it is not there the regulator is internal to the PCM. Alternator bad, alternator brushes bad, regulator bad, all three could be the culprit. Just exactly when the switch over to PCM regulator happened is a mystery especially on a 91. Good luck.

 

[1stgen4evr]

charging problem

225k miles, you could have worn out the brushes in the alternator but probably not. Brushes are the first thing to go and often you will pay big bucks for a rebuilt when you only need the brushes replaced. Sometimes the diodes will fail and after really long service the bearings. The 91 will be the same as my 89 (I think) and the regulator is on the firewall over the exhaust manifold. Some are chrome plated but yours may not be. It is a small (about 4 inches by 4 inches) half inch thick metal covered thing-a-ma-bob.



On some models of gas engine vehicles, the alternator is mounted in such a place that it takes a great deal of heat which will shorten the life of the diodes. The Cummins doesn't put out the heat that a gasser does and the alternator is mounted in a relatively cool air stream. Our alternators are pretty solid and will usually give longer service than what you now have. If you have had a poor battery or you have had cranking problems, and the alternator has been required to work harder for these years, it may be the problem. I am very fortunate in that my uncle repairs starters and alternators and I can just take my truck by and he checks the output of the alternator.



My 92 on the other hand has experienced lots of problems with charging due to a faulty PCM. I had the brushes replaced and still no charge. Unc put in an aftermarket regulator that mounts on the alternator and ended the problem.



Hope this helps.

James

 

[matches]

I had charging problems and I replaced the voltage regulator, at the tune of $20. 00 or so, fixed me right up, try that first and then go from there. You can always go to the parts store and get each item checked. I used a voltage tester and was able to find out the regulator was bad. I think mine only had two wires from it, but it is on the firewall almost to the top about 4" left of center.

 

[jaynes]

getting worse...

I'm running on battery power alone now... it's like having your lights on without the engine running... even my turn signal is getting sluggish! The last time I started my truck tonight, i could tell that there was a noticeable drop in cranking speed. Yeah, the battery can't take it much longer. The battery is a group 31 and is brand new. Never had cranking problems or battery or charging problems before. The last time i looked for the regulator, I couldn't find it, although i didn't know where to look! So I may not have been knowing what I was looking for, cause I didn't know what it looked like either.



Say that the regulator is built into the PCM on my truck. Then what? New PCM? Start with replacing the brushes in the alt. first? My goal is to get the job done quickly with as little amount of money as possible... wait, isn't that everyones goal?



Josh

 

[jaynes]

I forgot

to ask where (if I indeed have an external regulator) to find these regulators. Dodge? Cummins?



Thanks!



Josh

 

[REaster]

Most auto parts stores will have the regulator.

Rich





1990 250 4x4 stock 230k

 

[1stgen4evr]

regulator

Go to the parts store and ask for a regulator for your year. You will then know what it looks like. Find it on the firewall of your truck. I don't think you have the regulator in the PCM for your year.



James

 

[jaynes]

That's encouraging! I'll keep ya posted. I'm checking into it later today. Thanks for the help!



Josh

 

[jaynes]

wouldn't start this morning...bah!

I do have an external volt reg though, so I'm going to O'Reilly's to pick one up... we'll see what happens.



Josh

 

[jaynes]

Well, it wasn't the voltage regulator!!! :{



Now I'm gonna have to dig into the alternator. I was lucky I made it home before there wasn't enough juice to hold the fuel shutoff solenoid open! This sucks...



Josh

 

[dpuckett]

Check all your connections from the alternator to the battery. With the high humidity in this area (that's most of the midwest), things tend to corrode faster than they do in higher, drier climates. I have had more battery/ electrical trouble in my 91 in the past year than I did in all the other vehicles combined out west. It is most likely something in your alternator- it is just about as cheap to have it rebubuilt as it is to get a reman from O'Reilleys. Shops today want the money for rebuilding the whole thing. Or, more likely, they dont want you coming back with a complaint about something else in a few months.



They went to a PCM in the 91s that got intercooled. No (factory) intercooler, no PCM Oo.



BTW- the shut-off solenoid will stay open with 4 volts from the battery. DOnt ask how I know that.



Daniel

 

[jaynes]

Would you believe it? NO ONE around here has a brush kit for these alternators... no one! I went to every auto parts store and dodge/chrysler dealer in town. I'm going to buy an alternator ( I believe a reman nippendenso ) from this place... $119 with the old one. Not bad considering some of the other prices! Now Daniel, you know I'm going to have to ask. . How do you know the shut off solenoid stays open with 4 volts? :-laf



Josh

 

[tugboatphil]

Josh,



If you haven't already spent the big bucks, look in the phone book for a shop that specializes in batteries. They often do alt and starter repairs.



Even if it wasn't the regulator this time, they do fail a lot. I used to get them for $15-$20 and would keep a spare in the glove box.

 

[dpuckett]

Now Daniel, you know I'm going to have to ask. . How do you know the shut off solenoid stays open with 4 volts? :-laf

Ok, here we go. Was on a trip in March00 to my now-ex fiance's sister's wedding in MN. ALternator locked up just east of the WY/NE line, snow coming down hard. Decided to turn the radio off, and plug along (night of course) as far as possible. Got about 150mi, stopped at a truck stop, got the battery recharged, and went another 150mi. (we had gone out of the snow by then). Stopped in a small town, found a NAPA store, and sat on the parking lot with the truck idling (25deg outside) from about 4am to 7:30 when they opened. Battery was shot- only put out 4volts, and only took 6 total on the charger. Got taken for $240 for a REMAN alternator (which only lasted not quite 3 years ), plus another $150 for a battery. Hence, my avoidance of all things NAPA sine then, unless there is NO alternative. Often times, it just dont get fixed in that case.



-DP

 

[jaynes]

Got 'er done!

Well, sorry Phil, I went ahead and spent the big bucks... bought a REMAN from a small shop here in town that only cost me $128 when all said and done. Well I got back with it after class this morning and went out to the truck only to realize that the stupid spacer dealy thingamabob that the put in the bottom bracket (can anyone tell me why that is there?! ) was cutting me short about 2 mm. SOOO... i hitched a ride to a hardware store not far from where I live, picked up a file, walked back to my place, and started to file it down to fit the bottom support. After about half an hour, I finally got it to where I needed it. I also found an interesting way to get the belt back on without messing with a cheater bar and wrench on the idler pully . Then I bolted all the wiring back on and such (also found out I'm WAAAY over due on an air filter!! ) and jumped him back to life. That only took ten minutes considering I was using a ford tempo with a teeny tiny little battery on my big boy group 31 that was deader than my would be 15 year old gerbil! Back to life and running strong.



Good story by the way, Daniel. By the way, Danny Boy, you don't by chance happen to have, oh, say, an HX35 or 16cm2 housing laying around, do you? I'm looking to upgrade! THanks for the help, guys!



Josh

 

[Cowboy832]

I had almost the exacty same problem last weekend. I started with the voltage regulator, and when that didn't help, I removed the alternator and had it tested at a local parts store. They said the alternator was fine and was charging just like it was supposed to. I checked all the wiring all over the truck, and couldn't find any problems witht that, so I started to get worried because the only other thing I could think of was the PCM. I don't know exactly how much a replacement would cost, but I had heard that they are pretty expensive. I changed the voltage regulator one more time just to make sure I didn't get a bad one the first time, and had the alternator tested again in a different store. They told me the same thing. In desperation, I took the truck to a local repair shop that specializes in auto electrics and had them look at it. They found the alternator was bad and rebuilt it for $120. The truck charges like a champ now. I just thought it was odd that two different parts stores tested the alternator and both said it was good.

 

[jaynes]

Huh, yeah that is wierd!



I have trouble trusting parts stores sometimes. For that exact reason!

 

[dpuckett]

Sometimes I think it would be worth it to buy all that crap to test stuff yourself. I had a part store (believe it or not, it wasnt AutoZone) put the leads of their tester on the battery terminals, then tell me the alternator was good. This was about 2 weeks before the fiasco in NE.



Josh, if I had an HX35 or 16 cm housing lying around, it would be ON THE TRUCK by now- remember, I hav e2 of them to keep up with. I have an H1C that needs rebuilt, and a 22cm housing. Make you appreciate your 18. 5 :-laf



-DP

 

[JLEONARD]

 I think it would be worth it to buy all that crap to test stuff yourself

Daniel, That still might not help all the time.

Two years ago my truck was not turniing over fast enough to start in the morning. So I tested the battery using my son's batter tester at his shop... . the kind that puts a load on the battery.

The tester showed the battery to be fine, yet it wouldn't turn the engine over after sitting all night.

New battery solved the problem.

Sometimes it ain't that simple I guess.



(Hey. . I "aquired" another 18. 5 cm housing!!! :-laf )



Jay