After two days and 2 dead batteries, timing lights, dwell meters, new spark plugs/wires and about 5 trips to kragen, I finally fixed all the okie **** ups the guy had before me on my pickup. Runs great, sounds great etc... The only problem is, My battery is not charging when the pickup is running. I have a voltmeter, and got 12.6 volts when I tested the battery and about 11.8 when it was running so its definitely not charging and my dash agrees (leaning on the D side instead of C). I have the alternator with the single pole coming off the back side of it. I read in another thread that you take your positive lead of your multimeter, put it on that single pole, and then just attach you negative to any ground, like the block. I did that and got nothing. Is this a good indication of my alternator being bad or do I need to be at a certain RPM to test it? Thanks guys, Oh and this truck is for sale, check my listing. It runs and I plan on driving it for the first time sometime this week. this has been a good distraction from studying for finals and my senior thesis. AJ
Some of the single wire alternator's require some rpm before it will charge. Mine likes about 1200 or so. You may want to check it with some increased engine speed.
If its a Chevy alternator, it's likely that its not a true "one wire." If it has two poles next to the main one wire connection, make a jumper from the #2 pole to the main. This activates the alternator charging. -scott noteboom
I got off work early, came home had my roomate rev it up for me at a steady 1600 or so, battery is still at 11.8 or 11.9, but I did go from the alternator main terminal to a good ground this time and it read 19.8 or so. Is that a normal Voltage output for an alternator? I think if that sounds right then Its definitely after that relay on the firewall.
When you say the "relay on the firewall" do you mean the voltage regulator? I have never worked on a externally regulated alternator system but would think that if the alt is putting out 19.8v the regulator could be bad. You may also have a wiring issue. Post a picture of the alt and "relay" and I will look at it....
Okay okay, so its been a while.... I had the alternator bench tested and the old timer at Napa says it works. which is good. My pickup had a voltage regulator on the firewall because it needed it with the old generators (alternators back then?). The guy said that I can just run an 8 gauge wire from the pole to the main lead on my starter (the same lead with the wire coming from the battery) and that will charge the system. This worries me but he said that I have an internally regulated alterantor and have nothing to worry about, i.e. don't need to use the regulator on the firewall. I'm thinking I could do this, and then just get the multimeter out and test the voltage and shouldn't be too crazy, like 14-16 volts right? Any electrical guru's thoughts on this? I could take some pictures of the alternator if this would help. Has anyone done this before?
If you left the wire connected to the terminal when you did this, then it means there is no connection between the alternator output, and the battery! so it would not be surprising that it doesn't charge.
If you have the rectangler 3 terminal volt reg. still on the firewall, run a heavy wire [10 gauge] to the terminal marked B or BAT on the old reg. Then it will read through your ampmeter in the dash. Note : if it is a low reading meter either wire it with a shunt or byp*** and add a volt meter, like a 30-0-30 reading meter.
An alternator in good shape with all the connections hooked up should charge 14.2 volts or very close to that. Before folks get too carried away with advice and suggestions, which alternator do you have on the vehicle? Can you post a photo of the back side of it as it sits in the car right now? That would help clarify a couple of things. The reason I ask is that we need to know if it is actually an internal regulator alternator. The internal regulator alternators will have the spade connections for the field an exciter wires going like this _ _ The connectors on an external regulator alternator go l l There are several good alternator wiring diagrams posted on the net but I am at work at the moment and don't have access to the ones saved on my laptop.
Awesome! I have an internal regulator then. So this means I can just wire it to the main lead on my starter then? (i have the _ _ connectors) I was gonna take a picture, and then realized that my camera is no where to be found. After searching the gf's house, my house, my truck, my garage, my buddies house, nothing came up. I think it got stolen at the last skate jam we had at my buddies place. Solid $300 graduation present down the drain. Thanks for bearing with me without the camera.
Not as shiny and I don't have that fancy plastic plug you got! but yeah, same basic thing, the pole out the back (thats called pole #2?) which was connected to one of the prongs where your plastic part is connected. I'm pretty sure it is this one. It looks just like it. http://www.madelectrical.com/electricaltech/delcoremy.shtml thanks guys!
There are some cheap, better alternators out there. When wired correctly they perform without a care and if they ever fail, 19.99 will get you back home. http://www.chevytalk.org/fusionbb/showtopic.php?tid/164343/
Hey All - Its been a while, first year of grad school put things on the back burner. Anyways, finally got started on this again, but this time I have a camera. Here is what I am working with: So there we go. Now, down to the questions. What size gauge wire should I run from what pole on my alternator to the main pole of my alternator? When I do this, the best way to check for voltage is from just the terminals on the battery correct? And it should read somewhere above or around 14V? thanks for all your help. I'm going to go drop off the battery to get recharged right now. AJ
i don not see a wire with 12 volt + switched power going to the terminal marked # 1 on the alternator.....that should be there as it excites your alternator
hmmm...Is that the empy prong ( the ones that look like " _ _ ") ? If so, I need one from that to the positive terminal on my battery? or the accessory from the starter? what gauge?
yes, looks like that. they are marked 1 and 2. 2 is wired properly , 1 has no wire and needs one. you want a 14 gauge wire that supplies power ONLY when the ignition switch is on...do not connect it to your battery! FYI , your really have no need for that voltage regulator...but the way you have it wired you are just using it as a junction box , so it is ok look at the picture in post 13 and you will see the wire you need here is a diagram:
thanks for your input , and for the subtle way you expressed it. yes , a diode may be necessary if you get engine run on ...which will not happen without a diode if it is wired properly. i see by some of your other posts you seam consider yourself a hot shot wire expert , so in the future i will defer all wiring questions to you. i have only wired maybe 30-40 cars in my lifetime so i'm sure my knowledge falls short of yours
using a diode to prevent backfeed usually depends on which internal regulator you have. when i wire up an old tractor its a hit or miss on needing the diode. never have been able to tell the difference of internaly regulated GM alts.
for the "10-GA wire to junction block or ammeter" I want to just byp*** both and put it directly to the battery or the main pole on the starter. I don't have the dash wired and I dont think I will until I get a rebel wire harness....a whole loom was melted from previous owner so I just want to be able to charge when its driving. I took the battery in and it was rocking 9.3 V and 6 amps....about 670 amps short of what it should be. now I have to buy a new battery. what do you all think? thanks! AJ
Another way to do it without the diode is to wire the "exciter wire" to the ACCESORY side of your ignition switch.
and neither does swearing at me.... let's leave it at that , i know what i know and do it the way i do ....and i know what you are
I saw a wire on the firewall next to the old regulator with the end taped. If that wire came off the original regulator to your idiot light/amp gauge or switch you can connect your missing wire ("the wire you need") to it (but not on the old regulator) and your problem should be solved. Connecting "the wire you need" to the taped wire you have should also eliminate the need for any diodes, They say the alternator needs to get to 2000 RPM to excite the internal regulator...I don't know if it needs to get to 2000 Rpm but it does have to get some R's before it starts charging.
Run the empty connection to the "R" terminal on your starter, no diode, no ********, it cant backfeed and will excite the alt.
I brought the battery in and it had 9V and about 6 amps. I guess it sat for a while. I have to wait to get paid to get another battery because kragen said that they won't charge it.
The Jalopy Journal
