High Voltage Surge

[Rawze]

I paid $1100 for a 320-AMP leese-neville at fleetpride. No core.

[CFR__AND_SONS]

Reviving this thread!

My truck is the Limited trim (not sure if it matters) so I've found out that everytime I need parts, they are more expensive than the other trims.

Anyways, I held off on replacing the alternator but it just started raining and sure enough the high voltage came back. I'm 98% sure that my truck takes the other high amp alternator (will double check with dealership) but I dont have TV, fridge, or microwave or anything but a amplifier and subwoofer. Do I HAVE to replace the alternator with the high amp one?

When I started this topic, my voltmeter always read 14.7-14.9. I got it checked and the electric said it was fine even though I really feel like its too high.

I'm hoping that when replaced, the surging will go away.

[CFR__AND_SONS]

Turns out my truck take the 165 Amp alternator but its not in stock. Called fleetpride and they have a 170 Amp Delco in stock for less than 500. Would the 5 extra amp make my voltage go up even more? or is the new alternator suppose to fix the high voltage?

I wanted to go with a Leece-Neville based on your guys' comments but I cant find a part number. I checked their website but couldn't find it on there using their application guide...

[Rawze]

(12-16-2016 )CFR__AND_SONS Wrote:  Turns out my truck take the 165 Amp alternator but its not in stock. Called fleetpride and they have a 170 Amp Delco in stock for less than 500. Would the 5 extra amp make my voltage go up even more? or is the new alternator suppose to fix the high voltage?

I wanted to go with a Leece-Neville based on your guys' comments but I cant find a part number. I checked their website but couldn't find it on there using their application guide...

The size of the Alternator should not make the voltage higher.


For the new one, the voltage on most will be 13.8 - 14.1 ish. Some are 13.6 - 14.4, and for gel-cell batteries, it needs to be 13.2 only. -- If it is outside of this range, then you may have other problems too.

Some Alternators/trucks have a feedback wire to help regulate the voltage at the batteries, some do not. Unless you have gel-cells or some kind of special type of battery that specifically needs it, I would suggest disconnecting any remote sensing and just jumper it at the Alternator so that it only outputs a steady voltage. Less problems long term that way. The instructions that come with the Alternator usually show how to jumper it when remote sensing is not used.

Lastly, if you have a prostar, your truck takes a pretty standard "pad-mount" style. There are lots of brands and sizes avail. Don't get taken just because some person at a distributor is too lazy or dumb to look it up correctly.

Here is one that would have worked just fine on my prostar if I didn't have that 4,000 watt inverter...

https://www.peterbiltparts.com/electrica...700018rman


-- Make sure you buy a new pulley for it too. Always a good idea, as most people damage/scar the old pulley trying to get it off. That and the fact that the old one gets polished from road dust and use, and it is more likely to slip under heavier amp loads.

[CFR__AND_SONS]

(12-16-2016 )Rawze Wrote:  

(12-16-2016 )CFR__AND_SONS Wrote:  Turns out my truck take the 165 Amp alternator but its not in stock. Called fleetpride and they have a 170 Amp Delco in stock for less than 500. Would the 5 extra amp make my voltage go up even more? or is the new alternator suppose to fix the high voltage?

I wanted to go with a Leece-Neville based on your guys' comments but I cant find a part number. I checked their website but couldn't find it on there using their application guide...

The size of the Alternator should not make the voltage higher.


For the new one, the voltage on most will be 13.8 - 14.1 ish. Some are 13.6 - 14.4, and for gel-cell batteries, it needs to be 13.2 only. -- If it is outside of this range, then you may have other problems too.

Some Alternators/trucks have a feedback wire to help regulate the voltage at the batteries, some do not. Unless you have gel-cells or some kind of special type of battery that specifically needs it, I would suggest disconnecting any remote sensing and just jumper it at the Alternator so that it only outputs a steady voltage. Less problems long term that way. The instructions that come with the Alternator usually show how to jumper it when remote sensing is not used.

Lastly, if you have a prostar, your truck takes a pretty standard "pad-mount" style. There are lots of brands and sizes avail. Don't get taken just because some person at a distributor is too lazy or dumb to look it up correctly.

Here is one that would have worked just fine on my prostar if I didn't have that 4,000 watt inverter...

https://www.peterbiltparts.com/electrica...700018rman


-- Make sure you buy a new pulley for it too. Always a good idea, as most people damage/scar the old pulley trying to get it off. That and the fact that the old one gets polished from road dust and use, and it is more likely to slip under heavier amp loads.

Thank you. I ended up getting the Delco Remy 160 amp. Slapped it on in about 1.5 hrs. Volts at the batteries are right at 14.1 like you say. I did hook up the remote wire to the alternator. How does jumping it at the alternator = less problem in the long term? Just wondering.

Thanks again.

[Brock]

Heck I just put a paccar alternator on and it works just fine.

On my peterbilt I had my voltage at 14.5 and was told that's fine.

alternator fried so I changed it, then the batteries went so I changed them.

back to normal.

I don't know which caused which to fail. chicken or the egg.

[Rawze]

(12-16-2016 )CFR__AND_SONS Wrote:  

(12-16-2016 )Rawze Wrote:  

(12-16-2016 )CFR__AND_SONS Wrote:  Turns out my truck take the 165 Amp alternator but its not in stock. Called fleetpride and they have a 170 Amp Delco in stock for less than 500. Would the 5 extra amp make my voltage go up even more? or is the new alternator suppose to fix the high voltage?

I wanted to go with a Leece-Neville based on your guys' comments but I cant find a part number. I checked their website but couldn't find it on there using their application guide...

The size of the Alternator should not make the voltage higher.


For the new one, the voltage on most will be 13.8 - 14.1 ish. Some are 13.6 - 14.4, and for gel-cell batteries, it needs to be 13.2 only. -- If it is outside of this range, then you may have other problems too.

Some Alternators/trucks have a feedback wire to help regulate the voltage at the batteries, some do not. Unless you have gel-cells or some kind of special type of battery that specifically needs it, I would suggest disconnecting any remote sensing and just jumper it at the Alternator so that it only outputs a steady voltage. Less problems long term that way. The instructions that come with the Alternator usually show how to jumper it when remote sensing is not used.

Lastly, if you have a prostar, your truck takes a pretty standard "pad-mount" style. There are lots of brands and sizes avail. Don't get taken just because some person at a distributor is too lazy or dumb to look it up correctly.

Here is one that would have worked just fine on my prostar if I didn't have that 4,000 watt inverter...

https://www.peterbiltparts.com/electrica...700018rman


-- Make sure you buy a new pulley for it too. Always a good idea, as most people damage/scar the old pulley trying to get it off. That and the fact that the old one gets polished from road dust and use, and it is more likely to slip under heavier amp loads.

Thank you. I ended up getting the Delco Remy 160 amp. Slapped it on in about 1.5 hrs. Volts at the batteries are right at 14.1 like you say. I did hook up the remote wire to the alternator. How does jumping it at the alternator = less problem in the long term? Just wondering.

Thanks again.

because the higher the voltage at the batteries, the shorter the lifespan they have, hotter they run internally when they are at full charge already. It will also mask wiring and corrosion issues by making the voltage at the alternator very high sometimes to compensate.

Just some things I have seen,.. others results may be different.