Hello everyone. I was getting a red light on my dash indicating alternator problems. I checked the battery voltages while running, and they were both at 14.4. A guy here said that the diode was probably going, so I bought a new alternator. Had to change the pulley - other than that it went smoothly. The red dash light is off now, but when I check the batteries while idling the voltage constantly jumps around, anywhere from 13.1 to 14.1. Any thoughts??

 

Pull off the pulley and take it back. Probably a bad voltage regulator.

 

Where is the new alternator from? whatever you do DO NOT buy one from autozone they are complete crap, when i purchased the truck it came with a autozone brand alternator and it went out, so i replaced it with a new one from autozone because it was still under warranty and still had problems with it so i finally just went and bought one from oreillys and no more problems.

 

Yeah, I kinda thought voltage regulaor too (not because I know anything about alternators, but the name seemed to indicate that it regulates voltage so...).

I bought it off a guy on ebay. He bought it last year from DB Electrical and never installed it. I emailed them (DB), but they were closed for the weekend, so we'll see what they say today.

Thanks guys. Have a great day. Michael.

 

Heard back from DB - they said that it can't be the voltage regulator because if it was, it would either undercharge or overcharge, but not jump around. They told me to check the connections, which I did and they were fine, and then they suggested increasing the RPM's. I brought her up to about 2000, and then it seemed to work normal - no jumping around, and stayed at 14.39-14.40. The tech then told me that I need an overdrive pulley, and that would fix the problem. So I ordered it, and should get it in a week or so. Not sure why this needs one to work properly when the last alternator worked properly without one, but anyway, we'll see what happens when I get it. I'll post back in case anyone reading this in the future has the same issue.

 

I've always had good luck with everything I purchased from DB... Good Luck. Hope the new pulley solves your problem.

 

The alternator should work fine with the stock pulley. It shouldn't need an overdrive pulley. That just seems like a way to cover up a different problem.

 

Final update. DB sent me a pulley (their item 24-2266) which they said was an overdrive pulley. When I looked at it, it looked the same as my stock one, but they swore it was different, so I installed it. When I did, the belt started squeaking which I guess means that it was at least somewhat smaller, so I ordered a shorter belt. Most belts for this truck ate between 119 and 120 inches (see Rockauto.com 1995 FORD F-250 SUPER CAB Belt). I found one from Dayco that was 117.9 inches (part #5081178/8PK2995). Installed it with no issues, and the alt now reads a steady 14.30 at idle (approx 650 rpm). So, I guess DB was right. Somehow it is now working just fine. I have since found out that the alt is 220 amp, so I'll do the 4 guage fused charging wire mod they recommend. Anyway, hope this helps someone down the road. Michael.

 

It just wasn't spinning fast enough to generate the proper voltage and the regulator was fighting it. Glad you got it worked out.

 

Yeah, I guess that makes sense, because when I first got it, it would charge fine at 1500-2000 rpm, but really jumped around at idle.

 

If its a 220 amp alternator then it was the belt slipping causing the weird voltages. You should get a Gatorback belt for that alternator. Also run 1/0 gauge charge wire with a 250 amp fuse.

The overdrive pulley was not needed.

I have a 200 amp alternator and run 1/0 wiring 250 amp circuit breaker and a gatorback belt.

 

x2 car audio guys do (the big 3) you can google it or check out vids on youtube.

 

Db Electrical only recommends going 4 guage with a 250 amp breaker. You think I need to go as heavy as 1? I was going to hook it up to the battery closest to the alternator. Any thoughts?? Also wonder of you know of any way to test the amp output on an alternator...

 

If it was a slipping belt, it would have got worse when he put the smaller pulley on, not better.

 

Yes I would not run 4 gauge with 220 amps.

http://www.knukonceptz.com/productDe...m?prodID=KFX0R Stuff is good for 300+ amps.


http://www.knukonceptz.com/productMa...0Fleks%20Kable


<table align="center" bgcolor="#FFFFFF" border="0" cellpadding="3" cellspacing="1" width="100%"><tbody><tr align="center"><td class="gbard">Cable Size
Wire Gauge</td> <td class="gbarlt">Current Capacity
Amperage (amps)</td> </tr> <tr align="center"> <td class="gbard">1/0</td> <td class="gbarlt">350</td> </tr> <tr align="center"> <td class="gbard">2</td> <td class="gbarlt">225</td> </tr> <tr align="center"> <td class="gbard">4</td> <td class="gbarlt">150</td> </tr> <tr align="center"> <td class="gbard">8</td> <td class="gbarlt">100</td> </tr> <tr align="center"> <td class="gbard">10</td> <td class="gbarlt">60</td> </tr> <tr align="center"> <td class="gbard">12</td> <td class="gbarlt">40</td> </tr> <tr align="center"> <td class="gbard">14</td> <td class="gbarlt">25</td> </tr> <tr align="center"> <td class="gbard">16</td> <td class="gbarlt">15</td></tr></tbody></table>

I would look into marine terminals also.
Here is a picture of my wiring.. lol






Yes it would be a great time to upgrade grounds.