Which part is bad

[Red Rattler]

Got a question, went to town in the 2000 Dodge and made 4 stops. on the way home I hear a ding and look at dash and it says check gauges. the alternator gauge was on zero. we wasn't far from home and when we got here I shut it off and tried to start it back. I heard one click and that was it. now it won't even make that. the batteries check out good. putting out nearly 13 volts. lights are good and bright. what would make the alternator gauge stop working and then not start when batteries are still hot. it's never had an alternator or starter or starter switch put on it. could it be key switch. may be the alternator. but shouldn't it still turn over if the batts are good? I know I've had starters do this. but never noticed the alt gauge going before it happened. trucks 20 years old and never had a starter or alt replaced.

 

[BigPapa]

I’d start by checking all you battery cables and terminals, then your grounds. It’s been common lately for the crossover cable to go bad. There’s also the battery temperature sensor under the driver side battery. If it’s bad it will keep the alternator from charging. If all that’s ok, I’d check the alternator. Be warned, I’ve heard of several fellows having their alternator checked at Autozone, Advance, or O’Reilly’s, and them say it’s bad and it wasn’t or that it’s good and it wasn’t.

A buddy of mine had this same thing happen to him the other day. He said he checked his cables but when he went to take the batteries out, found on of the universal clamp-on terminals he’d installed with the pretense of doing it right later, loose and heavily corroded under the clamp. The cable pulled right out of it and after further inspection, it had arced and melted away the body of the terminal.

 

[GAmes]

My best guess is you have two failures that occurred close together. Have you checked fuses, both in the cab and under the hood? Have you tried jumping the starter to see if it spins?

 

[Red Rattler]

Battery cables and terminals are all clean, I looked at the fuses under the hood and didn't see none that looked blowed. Have not tried jumping the starter yet. was going to see if it's getting voltage to it when it stops raining. The gauge just went to nothing all of a sudden. it was normal earlier. I need to get it running to check out anything. I will try jumping the starter first. The cable ends look good but could be corroded under the plastic.

 

[DavidC]

You could also try tapping the solenoid, maybe bad contacts. Just happened to the wife's van a few month's ago. Kind of a coincidence when it all happens at once tho.

 

[DavidC]

2001 circuit

 

[Red Rattler]

Thanks for the replies, i'll try all of the ideas. how would I check the starter relay switch under the hood in the fuse box?

 

[Ozymandias]

You checked all ground wires on BOTH ends?

You can have perfect voltage on both batterys but the alternator not charging and starter just clicks directs me on the ground to the engine block.

Easiest way to check - fiddle a small gauge wire between one negativ battery post and engine block, try start truck, if the wire burns up you nailed it.

 

[Red Rattler]

You checked all ground wires on BOTH ends?

You can have perfect voltage on both batterys but the alternator not charging and starter just clicks directs me on the ground to the engine block.

Easiest way to check - fiddle a small gauge wire between one negativ battery post and engine block, try start truck, if the wire burns up you nailed it.

Have not checked that, I will try that too. thanks.

 

[Red Rattler]

After running test all morning, starting at the battery, I finally got to the starter relay, I wired around it from the fuse box and truck fired right up. so ok that's bad. go to parts store and get one and bingo. fires up. I checked the alternator while it was running and it is bad. not charging at all. I figured the alternator let loose and blew the relay. I haven't replace the alternator yet. didn't buy one. wanted to make sure the relay was the problem. but it will be a piece of cake. it's 150 bucks. gonna wait till all this rain passes through to change it. Thanks for the help guys, i really appreciate it.

 

[DavidC]

Save the old one and rebuild it. A lot of bad karma from store bought units.

 

[Red Rattler]

Uh Oh, what's happening. there a thread here on it?

 

[BigPapa]

There are lots of posts in different threads about it, but this is the only one I can remember:

https://www.turbodieselregister.com/threads/234-987-mile-alternator.256936/

There are several of the same relay in your PDC. Instead of doing the wire-around, would have been easier to just swap one out. At least you know it's bad.

 

[BigPapa]

Here's another:

https://www.turbodieselregister.com/threads/alternator-original-new-denzo-vs-new-aftermarket.268032/

 

[Red Rattler]

Thanks for the links, think i'm going to order one of those nations alternators that was in one of those threads. It's pricy at 299. I checked to get it rebuilt and he wants 125. might get it rebuilt at some point.

 

[Cummins12V98]

If you have another ride get the OE rebuilt!!!

 

[Red Rattler]

Guess i'll take it off tomorrow and take it to the rebuild shop.

 

[BigPapa]

Where are you located?

 

[Red Rattler]

central Arkansas, I found a Nippodenso at napa for 150. The Bosch is 248 but they would have to order it. I don't know which one I have.