Duke Napalm

Hey guys, before I begin I just wanted to give a quick compliment to this forum. I may have just registered but I've already found lots of interesting new info.

Hoo boy, where do I start?

A couple of weeks ago I purchased an '86 camaro and have fallen deeply in love with it, in spite of all the headaches it's given me so far. Nothing under the hood is stock, it's got a punched out 350 of indeterminate origin. This leads me to my main problem. The wiring. Good God, the wiring. I've never seen such a mess. Everything is routed through four different killswitches and it honestly looked like colorful spaghetti under the dash. Redone quite a few of the connections, but for the life of me I -cannot- figure out why the alternator isn't charging. In the last few days I have replaced;

-Battery (brand new interstate)
-Alternator (brand new 110 amp)
-Various fuses and connections.

Now, I've got a standard 3 wire alt setup. When the car is on and idling it's putting out about 12.35 volts at the rear alternator post, I switch the fans on and it goes down to about 11.50 according to my multimeter. I've been checking wires for resistance and the hot lead that goes directly to the positive battery terminal as well as the two wires on the pigtail(at least as far as I can reach before they disappear into the harness) all test in at around .2 so they should be okay. Could one of those pigtail wires be shorted somewhere maybe? Even if they were, wouldn't the alt still crank out the 14.3 at the post like it was supposed to?

So, what gives?? Wiring has never been my strong suit so I can only imagine what I may be missing. Please feel free to ask any questions or for any info I may have forgotten to add.

Any and all help would be deeply appreciated! I'm kinda at my wits' end here.

Thank you!!

roysatikas

iTrader: (1)

Try verifying a good ground from the neg batt cable to the block, not yhe head if they are aluminum. New cables are cheap @ $10 for 32". That ALT should be showing somewhere @ 14.4 volts off the back post.
Good luck,
Roy

Duke Napalm

You know what? I... I think that might be it then. The main battery ground is actually secured to the bottom bolt that holds the alternator, which in turn is secured to the head, which is indeed aluminum. Man, I can't believe I didn't even think of that! Not going to have the time to mess with it for the next couple days because of my working schedule, but will definitely try to ground the thing properly ASAP.

I sincerely hope that's the problem. In the meantime, any other ideas/tips/suggestions?

Thank you!

Duke Napalm

So I was doing a little reading and I see that, according to the internet, aluminum makes a pretty decent ground if you watch out for electrolysis based corrosion which I had completely forgotten. It's been a while since I took a science class!

But now that I'm fixated on the idea, I'm still pretty convinced that it's most likely a bad ground. As I said before the main engine ground is connected to the long skinny bolt that the alternator rests on, between two washers. The bolt itself is just barely touching the heads, and something tells me that this isn't nearly sufficient. What do you guys think?

The original alternator I pulled off of the car I had tested at the local auto parts store, and they said it was perfectly fine. I was pretty mystified as it had been testing almost nonexistant at the rear post as well (like 12 volts flat) and the main ground was connected at the same spot. A pattern here, perhaps?

What do you guys think?

Thank you.

raceb8

make sure u have 12 volts @ the brown wire on th alt plug w the key on. if not th regulator wont excite & th alt. wont charge...

Duke Napalm

Well, ah, there actually isn't a brown wire. Pretty much every inch of wiring done in this car looks like whoever just threw all the little extra bits and pieces they had lying around together to make things "work". I've got the main wire from the battery directly to the post on the back of the alternator, and then a red and white wire connected to those two little plugs on the side of the alt. They disappear into the wiring harness. Which wire is the brown wire supposed to be?

Duke Napalm

Anybody?

NINÅ

Duke Napalm

Thank you, this actually ended up being half the problem. Redid a horrible splice I didn't initially see on this wire (which is red for me) and found an inline fuse buried under some other wiring that was bad. Solved!

roysatikas

iTrader: (1)

Duke, doesn't matter what color, as raceb8 states the heavy gauge wire to the 2 prong connect should have @ 12 V engine off key ON when disconnected and being tested. the smaller gauge wire sends input to the dash for volt meter or light. On my '91 the alt post wire goes to a distribution block behind the pax head light and then to the + batt cable/post. There are @ 4 or 5 wires out of that distribution block that are always HOT since that wire comes off the batt to the block, back to the alt post, interior & headlights, brake lights etc. See if you have this, can't remember if my '84 had it in the same spot. Get a 82-92 Haynes manual from Auto parts store, good wiring diagrams all years. Good luck, Roy