alternator help

[milo]

hi everyone... so i finished instaling my painless wiring kit on my 53 chevy and i thought all was well but then i noticed that the voltage while the engine was running never got above like 12.4 so i went out got a new batt and a delco 10-si alternator. i should tell you that i put in 350 for an engine. anyway i put it all in ran the wire for the term 1 made a jumper for term 2 and started it up.... 13.5 i thought i was all set then i went to tern it off nothing so i unplugged the reg and it turned off.. put in a diode problem solved but now 12ish volts??? have tried it all put in a light tried one wire tried a fake voltage into the field excite i got nothing and am in need of help

[VetteVet]

Refer to this website for some help.
http://www.6066gmcguy.org/charging.htm

I assume you had a generator on the truck. Did you have a charging light? Find the wire from the charging light that goes to the generator regulator and wire it to the sensing terminal on the 10SI alternator and then hook the jumper back up that went from the alternator Batt terminal to terminal 2 on the alternator. It may have an "F" instead of a 2 for field.

The website appears to be wrong to me in that the alternator terminals are backwards according to the description.

What did you get from Painless a stock 53 harness or something newer?

You can wire the red wire that goes to the external regulator to the Batt terminal and eliminate the regulator since the alternator has an internal one. You may or may not need the diode. Post back if you need more help.VV

[milo]

i put in the universal kit. there was nothing to start so no light, no ammeter.... the painless kit has a wire labeled field excite which is the one i used for the sense wire... i had to wire in a diode.... then when it wasn't working i wired in a light...

so right now i have

ign power-----------light------diode------alternator terminal 1

[VetteVet]

Well with the simplicity of the circuit you have, you may only be charging what the battery needs if that is the only load on the alternator. The charging light may not be enough resistance for the alternator regulator. You need around 80 ohms and about 5 watts. I would get the alternator tested and make sure it was working. On a setup like yours I don't think it would hurt a thing to start the engine and temporarily disconnect the negative post on the battery. If the engine stops then the alternator is not charging.I don't recommend this on the newer computer vehicles because of voltage surges but I have done it many times on the older cars and trucks and the only thing that went wrong was that I revved the engine with the lights on and they popped like flashbulbs, so don't do that.

we may need a diagram of your wiring circuit to determine where the problem is.

[fixit-p]

Originally Posted by milo

i put in the universal kit. there was nothing to start so no light, no ammeter.... the painless kit has a wire labeled field excite which is the one i used for the sense wire... i had to wire in a diode.... then when it wasn't working i wired in a light...

so right now i have

ign power-----------light------diode------alternator terminal 1

If the diode was installed backwards it would prevent power from getting to the alt and since it was working before the diode make sure the cathode (stripe on the diode) faces the alt.

[milo]

Originally Posted by fixit-p

If the diode was installed backwards it would prevent power from getting to the alt and since it was working before the diode make sure the cathode (stripe on the diode) faces the alt.

yeah the diode is in right..... im thinking maybe something is up with the regulator, cause to be honest i cant find anything wrong with my wiring....
and when i first put it in, it worked..... i just want 13.5 volts haha

could putting in the light if it wasnt need cause a problem??

[milo]

Ok so I started the truck this morning and stright to 13.5 worked for a little and then Went back to low volts I don't get it... Could it be that it needs a resistor in the exicte wire??

[stellar]

sounds like something really simple like a loose belt or loose connection. The wiring sounds right. Ign -lite - diode-alt #1. Is there a pos wire to #2 terminal?

[fixit-p]

Can you post a diagram of your system or verify it against this one.

[milo]

battery-------switch---------light-------diode----------terminal 1
|
|
|-----------------------10ga--------------------------BATT

jumper from BATT-----terminal 2

ruff diagram best i could do real quick. im thinking of putting in a resistor instead of the light.. also is it a certain type of light you have to use i just wired in one i had lying around.

[milo]

Originally Posted by stellar

sounds like something really simple like a loose belt or loose connection. The wiring sounds right. Ign -lite - diode-alt #1. Is there a pos wire to #2 terminal?

belts tight and i have checked every wire more then once. there is a jumper from the BATT post to the number 2.... im starting to think that the light i have in the circuit may not have enough resistance.... i dont know i have never had this problem before with any project

[stellar]

Once the alt is excited it will continue to charge even if there is no connection to #1. The alt can be excited by momentarily touching #1 to pos post and it will start to charge for as long as the motor is running.
Where are you getting the low volt reading? have you tried the meter on another car to see if it is accurate? Even 13.5 is low unless the bat is already pretty low. The wiring looks right. I am now led to believe you have a high resistance connection in the alt pos circuit or a bad alt. If the pos post on the alt is even a little loose inside or outside the alt it will do what you say it is doing.
You may try taking a reading volts with the meter connected from bat neg post to alt pos post, and another reading with meter connected from bat pos post and alt case to look for a problem. let me know what you get. Mark

[mike66]

did you say that it was a four wire alt.......if it is a four wire,i think the " L" terminal is tied to the exciter wire from your ign. switch....i think that is all you need other than the wire from your starter.


mike

[neonlarry]

AFAIK a resistor is only needed in the excite circuit of the CS series alternators not the 10si and usually ditto the diode. You also mention unplugging the regulator and it turned off, do you still have the external regulator connected?