okay, i just replaced my alternator thinking the old one was going bad, when i crank everything is fine but if i turn my headlights on the volts go down to about half, when i turn my heather on it dips damn near bottom causing my head lights and dash lights to dim dramatically.

which ever alternator i got from autoparts store is correct but if i were tog et the high performance alternator on ebay thats 200amp, this should resolve my issue but is it bad to go that route?

also should i get that alternator will it fry my system? do i need to change a lot of parts just to use this one?

 

Chances are you have a wiring issue. First off, go under the car and check the wires that are at the starter. There is a big black wire, and some other skinnier wires. They are held in by a nut. This acts as a junction box for the power wires for your car. Take the nut off, take a wire brush to the connectors and clean them up. Then put them all back on, making sure that the nut is tight. Afterwards start the car and try the headlights, wipers, etc. If you still have the problem go to the alternator, (with key off) and probe the individual wires at the alternator connector with the connector plugged in and the rubber boot removed. The larger fat red wire should read 12 volts at all times. The next one to it should read 12 or more volts with the key on engine on. Don't spend crazy money on an alternator, it may not even be the problem.

 

Yes i would agree with this statement. Also one way you can check to see if the alternator is putting out properly is with the car running check your battery and see what you are reading you should be reading over 13 volts. Then turn on everything you can and then check the battery again with the car still running and you should still see over 13 volts it you don't then like what he was saying check your connection is everything checks out then yes you need another alternator. also a high output alternator will not damage your system. there is an internal voltage regulator that will regulate all that voltage and amperage. Those are normally for cars that have a lot of extra electronics such as speakers and sound systems extra lights and so on. But yes check your alternator output and the connections. If the connections are tight and not corroded and the alternator is not putting out over 13 volts with the engine running then change to a higher output alternator.

Good luck

 

yea eventually i plan to put in a small system, going to make a box that will fit in the back well so it wont take up space. for now its jsut horrible when i turn headlights on or heat for defrost. i will check those connections and see, ty for the input guys huge help.

 

While you're checking connections, don't forget the ground connection at the block from batt negative. Also, make sure both cable connections at the battery are clean and tight. You don't say what vehicle you have. Some of the TAs had a junction block by the battery where accessory power connected. If applicable, be sure that there are no corroded connections there. The alt voltage test is good but I like to see 14 volts under all loads. Because you just bought a remanufactured alternator from the store doesn't mean it's any good. The rate of no good parts I see right out of the box is staggering. The higher quality brands(read as more expensive) tend to have less faults.

There is a fusible link in the alternator output wire right where it connects to the battery terminal of the starter. That fuse link can become so deteriorated that it barely passes power and can no longer support sufficient load. A volt drop test is the best way to find this kind of fault, or a fault in any wiring. Connect a volt meter, one lead at each end of the wire, while you place a load on the circuit. Any voltage that you read on the meter is voltage being lost in the wire. If you are losing more than .5 volts between the alternator output and the starter's batt terminal, you probably need to address the fusible link. Resist the temptation to just replace the fuse link with wire. The fuse wire is there to prevent serious damage(like a fire) in case of a short circuit. You can buy fuse wire at any auto parts store.

I run the Powermaster 240amp alternator in my car. It was the only way to support high output headlights, my blower, and my stereo system all running at once. It required an that I run a larger ground cable from the block to the battery and a much larger output wire from the alternator, directly to batt positive. I still could use better cables but the system works well now.

 

Yea sorry, it's the 1984 Pont Firebird v8 5.0.

My negative has a much smaller wire coming from the terminal that connects to the side raid above where the battery sits, should that be going to the block it's self?

I don't have volt meters and what not, just never bought one and plan to have my mechanic look at it next week, just found both struts and whole steering box needs to be replaced as well as inner/outer tie rods need to be replaced, gonna be about 1k in all lol sucks.

What lights are you running that makes you need over 200amp? I was thinking about Xenon but I thought those were supposed to consume less power then the current factory bulbs it already has.

 

I have "not legal for highway use" Hella housings with 80/100 watt H4 motorcycle bulbs in the dim positions and 110 watt H1 bulbs in the bright positions. I updated the headlamp wiring using relays to operate the headlamps rather than the factory method of routing full lamp power through the switch and 20 year old wiring. I learned automotive electrical as a technician for GM, so this kind of thing is fun for me. It's also what I do pretty much everyday at work. With all 4 brights lit, I have 420 watts of headlamps. I also have a 1000 watt RMS subwoofer amp and a 300 watt RMS 4 channel full range amp on the 4 cabin speakers, that makes for quite a bit of load. It used to be, if I ran my headlights, blower, and music all at once, my battery voltage would slowly drop until the lights began to dim and I had to shut at least one of the 3 off.

I tried a 140 amp " high output" alternator and it would just overheat and shut down every few minutes with all the loads on. Only the big boy Powermaster has consistently performed well. Powermaster makes good equipment. The first one I had went out after about 3 years. I called them and had a new one in my hands a few days later, no charge. Just had to send the failed unit back. That was 13 years ago. The 240 also mounted easily in place of the C130 factory unit in my 87. Just had to do a little fab work on the top alternator bracket and use a slightly longer belt. The Powermaster 240 is nearly identical in design to the C130, just about 5/8" larger diameter. Your application will probably be a little different. You may have the same C130 generator, but with a V-belt rather than poly-V.

I have bright, vivid light as far as my eyes can see and I can crank the tunes until my hearing goes and I never worry about draining the battery. Like I said before, I do plan on replacing both battery cables with some 2 gauge cables, probably when I install the new motor in a more few years. I wouldn't trade the lights I have now for HIDs, though the Hella housings could easily be fitted with HID units. I personally don't care that much for HID. If you do decide to go that way, my one word of advice would be avoid the temptation of cheap asian crap and go with Sylvania or GE. Sylvania created HID and their equipment is excellent as is GE. It's also much more expensive, but you pretty much get what you pay for.

 

thanks for the info brother, ill look into that today when i get to work.

 

Oh sorry, I forgot to mention, the small wire from batt negative to the body is a body ground. Leave it where it is, just be sure it has good clean conact. These things suffer from electrolysis and the connections develop resistance. There is also a larger lead from batt negative to the engine block. That is the main engine ground. Be sure it is also clean and tight and both ends.

 

And if you can, use a much larger cable on the battery to body ground and add another thicker ground from engine to body, preferably a frame rail instead of another firewall lead. The firewall is already a noisy connection.

 

I have the same issue with turning on the headlights, and kills power if I turned the heater on. I dives lower. thanks for the info! I also got a phantom coolant issue where its leaking somewhere, but I haven't pegged it yet. looses coolant when not running. I haven't drove it lately. I am missing the under fender on the passenger side, and their is that electronic box on that side. could that cause the voltage issue? gona check the listed above.

 

I am unsure what electronic box your talking about. On the passenger side of the car, is where the ECM harness passes through the body. Just in front of the door. Is that what you mean? That's not a module, just a pass through bulkhead. You really should try to get your fender liner replaced though. No need to be spraying road crud on the sensitive EFI circuitry. As far as your dropping voltage goes, all of the advice given to the OP in this thread is applicable to your symptoms. Check all grounds and the battery connections at the starter. Test your charging system to verify 14 volts under load.