Its alive partially

[RD400HP]

Well I got my Duraterms installed finally and with 2 good batteries the motor lit right up and sounded good. But my other problem wasn't fixed with the new battery its still not charging.

Here's my question .I have a 100 amp alt off a 94 Caprice will this work on my 95 if it bolts up or will there be computor problem's? I can get a new 105 amp off either Advance & Autozone for about $119 with a lifetime warrantee. Then there's reuilding it myself ,looking at some of Rock auto's price's on part's for the alt it look's like it could get a little pricey even me doing it.

I don't know if I burnt this alt out by jumping the truck on boost or it was just it's time. With the one battery being toast the alt had to be constantly charging I think. If it was my fault by jumping it anyone have any ideas what might need replaced? Thanks.

Mark

 

[ak diesel driver]

I believe the alts will swap. If you fried the old one from boosting it usually the diodes or regulator. If you swap make sure to keep the pulley off the diesel. Gassers use a diff dia and it will affect the tach

 

[RD400HP]

I believe the alts will swap. If you fried the old one from boosting it usually the diodes or regulator. If you swap make sure to keep the pulley off the diesel. Gassers use a diff dia and it will affect the tach

Thanks for the reply AK, I popped the hood on the Caprice to have a look see and it doesn't look like it would even begin to fit,the one on my 95 look's pretty small. You know the Caprice might be a 125 amp now that I think of it it was a cop car in it's former life .

I have another question for you how do you drive the outside bearing race out? Those 3 little indentions in the hub doesn't give you enough room to get a punch on it. Do you have to use a puller on it? I just had a thought most of you guy's have 4X4's this is 4X2 C1500. Thanks AK.

Mark

Mark

 

[ak diesel driver]

the one off my wife's burb will fit mine looks identical. I bet the police version is probably the biggest diff.

 

[WarWagon]

These alts have a full enough load with charged batteries. A single discharged battery is known to be more than enough to cook the diodes out of them. With two (for our diesel) bad/weak odds are very good that it caused damage to the alt. Damage shows up when it is bad enough to not energize and leave the red light on. Usually, if not the same day, the next day after the batts are charged by the alt the red light pops on.

Alt is rated at 105 amp full RPM, NOT AT IDLE. Why would GM install a more expensive and heavier fuel sucking alternator than the vehicle will usually ever need? Batts take ~6 amps each to charge when good the rest of the output going to the vehicle. A bad batt draining the good one puts the ALT at full output as they take way more than 6 amps each to charge. Low RPM makes cooling difficult. The diodes cook like this.

I would not use boost to start a vehicle. Surges kill stuff way to fast and often - just think of the expensive other electronics you have esp in the IP. Jump it or 10 AMP charge. Jumping is bad as the weak batts are left for the alt to charge but at least surge damage is less. Spark a jumper cable just once though...

 

[jrsavoie]

Right on the money

These alts have a full enough load with charged batteries. A single discharged battery is known to be more than enough to cook the diodes out of them. With two (for our diesel) bad/weak odds are very good that it caused damage to the alt. Damage shows up when it is bad enough to not energize and leave the red light on. Usually, if not the same day, the next day after the batts are charged by the alt the red light pops on.

Alt is rated at 105 amp full RPM, NOT AT IDLE. Why would GM install a more expensive and heavier fuel sucking alternator than the vehicle will usually ever need? Batts take ~6 amps each to charge when good the rest of the output going to the vehicle. A bad batt draining the good one puts the ALT at full output as they take way more than 6 amps each to charge. Low RPM makes cooling difficult. The diodes cook like this.

I would not use boost to start a vehicle. Surges kill stuff way to fast and often - just think of the expensive other electronics you have esp in the IP. Jump it or 10 AMP charge. Jumping is bad as the weak batts are left for the alt to charge but at least surge damage is less. Spark a jumper cable just once though...

 

[RD400HP]

These alts have a full enough load with charged batteries. A single discharged battery is known to be more than enough to cook the diodes out of them. With two (for our diesel) bad/weak odds are very good that it caused damage to the alt. Damage shows up when it is bad enough to not energize and leave the red light on. Usually, if not the same day, the next day after the batts are charged by the alt the red light pops on.

Alt is rated at 105 amp full RPM, NOT AT IDLE. Why would GM install a more expensive and heavier fuel sucking alternator than the vehicle will usually ever need? Batts take ~6 amps each to charge when good the rest of the output going to the vehicle. A bad batt draining the good one puts the ALT at full output as they take way more than 6 amps each to charge. Low RPM makes cooling difficult. The diodes cook like this.

I would not use boost to start a vehicle. Surges kill stuff way to fast and often - just think of the expensive other electronics you have esp in the IP. Jump it or 10 AMP charge. Jumping is bad as the weak batts are left for the alt to charge but at least surge damage is less. Spark a jumper cable just once though...

Thanks for the info WW, coming home from Wisconsin it was charging at 14 amp's but after I had to put the boost to it it was showing 12 1/2 volts after I had 2 good batteries in the truck. Maybe I'll see if I can get a 125 amp alt for it to help it along.

Mark

 

[WarWagon]

Gauge in the dash is volts only. Red light means the alt is toast. Low volts can also indicate that the alt is not putting out any power or the fusible link has blown in the wiring harness. I have seen these units go weak before complete tach and red light failure. My last one made 3000 miles from weak to dead... Weak was revving the engine to get the volts up and voltage dropping off at times.

Is the red alt light on?
Does the tach work?
How old are the batteries?

You should check out powerbastards.com or similar site for a high output unit. Make sure you keep your pulley and explain to them we have a tach driven off the alternator with a funky non common pulley size.

 

[RD400HP]

Gauge in the dash is volts only. Red light means the alt is toast. Low volts can also indicate that the alt is not putting out any power or the fusible link has blown in the wiring harness. I have seen these units go weak before complete tach and red light failure. My last one made 3000 miles from weak to dead... Weak was revving the engine to get the volts up and voltage dropping off at times.

Is the red alt light on?
Does the tach work?
How old are the batteries?

You should check out powerbastards.com or similar site for a high output unit. Make sure you keep your pulley and explain to them we have a tach driven off the alternator with a funky non common pulley size.

The battery light is not on the tach is working and the fuse link has been eliminated by thr PO. and the batteries are in good shape WW. All the check lights appear to be working before start up.

Mark