I need a suggestion in a bigger alt on my 85 T/A. I have added an electric fan and do not have enough juice to run everthing at night when the vehicle is idling would love to know what years and body styles have bigger amp alt that will interchange.

 

dunno if it helps any but i have an 86 t/a power windows, power locks, power driver seat, power hatch, a/c, and a 108 amp alternator. Although i think the clocking on the 86 is gonna be different.

 

I think anyone 87 and up is 105 amp Alt.

That should work jsut fine....

 

I would go with a A/C Delco 105 amp one that would bolt right in.
Stay away from the remanufactured junk at the Auto Stores.

 

Have an '85 'ROC and it came with a 108 amp alt. I would have thought that the TA would have had the same.

 

in my car the previous owner put in an high amp alternator for his audio system, not sure whats the ratings..

 

I did not think That A/C Delco made a 108 amp one, are you sure??

 

Thats what was stamped on it, 108A. I ordered the car when I was stationed in ND so it had to have heavy duty everything in it, cooling, charging, battery, etc.

 

85 you have the older 10si alternator. From about late 86 they switched to the newer CS type. In my opinion the 10si was a better unit. Going from memory I think they came in 35 and 65 amp versions. keep in mind a higher output alt will have LESS output at idle than a lower one. Alt manufacturers design the pulley size to get it throttled up around 1k rpms. If you want more output at idle you can simply purchase an undersize pulley. The drawbacks are this, with a smaller pulley the brushes may wear a little faster and you will remove some HP at the lower rpm. A typical alt when it's close to full output can use as much as 7-9hp to spin it. www.alternatorparts.com carries pulleys and kits to repair and upgrade most popular alternators. I have a 105 in my 89 and with everything running at idle the voltage drops somewhat, but in reality it's not a problem. The guage is not exactly accurate and when it says a little below 13 volts its actually 13.5-13.8 when measured at the battery. Unless you are having trouble maintaining the battery at at least 80% of capacity I would leave it be.

 

I'm with Danno on this, test your voltage at the battery with a multimeter, see what it is for real, load it up. Turn on the air, lights, stereo, blinkers...see if it keeps up. I'm not sure where the stock guage picks up its readings, but it always seems to read 1.5 to 3 volts low.

 

All technical replies aside, all he asked for was a sugestion on a bigger Amp Alternator.
I said, buy the A/C Delco 105amp one that will bolt right in and give him all the power he needs.

 

I know that the alt does not produce enough juice at an idle because if the car is left idling for long periods with the lights and the fan on it will die due to a dead batt and as I am planning to install an amp and subs next spring I just needed some suggestions as far as what I could use because with the amp driving around town could become a real hassle trying to keep the car running at the long stoplights in my home town.

 

im not sure but i thought i saw a high amp alt. rebuild kit in summit that would give you enough for your system when you put it in.

 

My apologies to your sensitivity about my being long winded. merely trying to give him info to make a decision with the least amount of money.:hail:

 

Danno don`t apologize I had not thought of the pulley and even though I am quite famaliar with cars sometimes a quick reminder to even those with the most experience can be of help I have checked those things that you mentioned but even cruising down the interstate and 2500-3000 (yeah so I speed a little) the voltage seems low with the blower on high lights radio and electric fan I know that I need a thermostatic switch to hook up the fan but have just not had time anyway just looking for alt suggestions and what would swap.