charging problem during heat

[Twista]

So, i was doing some research on high engine heat and alternator charging. It seems when its very hot outside the ALT doesn't charge nearly as well as it does when its cold. Its been about 100+ degrees during the day in Chicago so once you factor in the engine temperature plus the outside temp.. its freaking HELL under the hood.


Anyway, i noticed during the day my car VOLTs are very very LOW. If i have the A/C on during the 100+ weather my car doesn't charge while idle unless i give it gas. At night time when its cooler.. it charges fine.

I didn't think much of it but i turned my off to inspect some damage from a lady tapping my bumper and when i went to start it back up it barely started . (The starting had nothing to do with the lady tapping my rear bumper.. my voltage was already super low while sitting @ that red light)

Now does this have anything to do with my under-drive pullies or is it just my alternator?

 

[ttocs]

as I was reading it all I was thinking was "UDP's?"

When they slow down your alt, they also slow down its ability to cool itself by pulling air through it. It also increases the load on the alt since it is not putting out as much current so that also builds more heat. If you do alot of city driving you do not want them. I had them on my car but was happy I kept my stockers and was able to sell them for the same price I bought them for since I got them used. They are a band-aid solution to gaining more power but there is a price to pay. I know someone will get on here and say they have had them for 40 yrs on their sn and never had a voltage issue. Either they do alot of highway driving, or they are just lucky. Good news is that you will have no problem selling them.

 

[Twista]

as I was reading it all I was thinking was "UDP's?"

When they slow down your alt, they also slow down its ability to cool itself by pulling air through it. It also increases the load on the alt since it is not putting out as much current so that also builds more heat. If you do alot of city driving you do not want them. I had them on my car but was happy I kept my stockers and was able to sell them for the same price I bought them for since I got them used. They are a band-aid solution to gaining more power but there is a price to pay. I know someone will get on here and say they have had them for 40 yrs on their sn and never had a voltage issue. Either they do alot of highway driving, or they are just lucky. Good news is that you will have no problem selling them.

Well my ALT pulley is stock, but the the rest are UDP's. I think the high heat from the weather is testing my pullies. I know even if you have a stock ALT pulley and the rest UPD it will still slow down the ALT because the crank, water pump are smaller than stock (right?).

 

[ttocs]

the water pump size has nothing to do with the alts speed but the cranks pulley does slow it down.

Honestly I am not sure why people are suprised to have these issues with UDP's. Its the common problem with them, they are tough on alts... Have you replaced that one since you got the pullies? Most of the people I know that ran them were lucky to get 2 yrs out of the alt afterwards, again city driving mainly.

 

[Twista]

The pullies came with the car and i already replaced the Stock ALT because it failed.

This new ALT is a autozone special without warranty, but its still pretty new. I have a feeling the pullies are killing it =[

 

[ttocs]

I went through two in two years before I finally believed it. The temps in phoenix's summer can't be helped but can always be made worse.

If you don't have the stock pullies then put an add out saying you will trade someone for theirs. Should not be a problem to find someone that will do it honestly the kids love those things more then candy. There is a reason they are always annodized a cute color imo...

 

[Twista]

I went through two in two years before I finally believed it. The temps in phoenix's summer can't be helped but can always be made worse.

If you don't have the stock pullies then put an add out saying you will trade someone for theirs. Should not be a problem to find someone that will do it honestly the kids love those things more then candy. There is a reason they are always annodized a cute color imo...

LOL. Ya i brought some stock 95 GT pullies last year off a local guy. Just need them installed.

 

[Twista]

A local guy is about to swap them out. Ill let you guys know if my voltage problems goes away.

 

[CC'S95GT]

I noticed today my alt was putting out lower than normal volts. I still have my stock pullies and I was on the hwy too. it's 95*+ in ATL today. Again. Now I'm going to keep an eye on it more closely but I'm betting it's just the damn heat.

 

[ttocs]

they are less efficient in the heat and will generally put out less voltage the hotter they get. This is why the pullies are hard on them, the less voltage they put out, the larger the load on it gets, the more heat it makes - which makes it put out less voltage, which increases the load on the alt, which generates more heat and then puts out less voltag - do the math...

again if you spend more time on the highway then city, or just down the drag strip for a racecar then its not as much of an issue.

 

[GRN95DTOP]

My 95 is doing the same. I took my alt off and took it to the guy who rebuilds all my alt and starters. he tested it and said nothing was wrong. He cleaned it and regreased it. Put it back on and checked all my grounds. Still reading low on voltage. Oh i dont have UDP either

 

[Twista]

So is everyone having this problem because of the heat? I got my stock pullies back on and it seems better now.
100+ degrees is insane on these cars.

 

[BYEBYE2U]

mine has UDP's and I hate them! my car heats up sitting still pretty quick while in the heat and i think the pullies is the cause mainly. i'll keep a look out on the voltage now,i haven't looked at it in the heat yet.

 

[ttocs]

yes the heat will lower its output.

So do you feel the hp you lost? Didn't think so but you will notice you will watch your gauges less...

 

[Twista]

yes the heat will lower its output.

So do you feel the hp you lost? Didn't think so but you will notice you will watch your gauges less...

No, i dont notice anything, but i tell you what i do notice. When i open the hood of my car it look stock now without the pretty blue pullies lol. =[ Oh well its a trade off for something better for the car.

 

[Dr Fildo]

I don't have under drive pullies. Bone stock everything. I have had the same problem lately with the alt not charging properly when it's hot, especially when the a/c is on. The weird thing for me is that the problem is actually worse at NIGHT, particularly when I have the headlights on. When I stop at a red light, the battery indicator goes WAY, down, and when the light turns green, I have no power when I step on the gas. Feels like she's gonna stall.

I have made no other mechanical changes. The car did not do this when it was younger. I'd like to solve this problem too, but I have no clue.