Hi Everyone! I'm having a couple of problems with my '32 with a 392 Hemi in it (also has a 8:71 on it). Problems with the lower alternator mount (no room, belt hard to tighten, etc). I'm going to hopefully solve this by going to a Hot Heads Hemi upper mount. Their mount holds a GM style alternator. I don't really care for the look of the alternator up top but I'm tired of messing with it. My question is what's the highest output GM alternator available? (Alternator on their now doesn't put out enough to charge with lights on). I'd like the highest amp output available. Oh, it doesn't have to be GM as long as it fits. I have a high output stereo amplifier in it plus I'm a big believer in overkill! Thanks! Bill
Here is a 200 amp unit. Unless running a ton of stereo, I can't imagine needing that much. https://www.amazon.com/LACTRICAL-ALTERNATOR-PONTIAC-aluminum-WARRANTY/dp/B008EO37Z4 Here is a 225 amp, but a lot more expensive. https://www.summitracing.com/parts/pwm-48237/overview/make/chevrolet
kind of difficult question to answer...title of post asks how many amps you need, text of posts asks how many amps you can get. I have a 37 amp powering my blown 427. But the motor sounds too good to bother with a high power stereo.
I would be more curious why a standard alternator isn't charging though, unless you are running a lot of electronics.
Thank You Prewarcarsforme & Squirrel! Using a Volt gauge on the battery with the car not running it reads 12.5 Volts. With the car running the Volt gauge shows 14.0 Volts (at the battery). As soon as I turn the headlights on the Volt gauge drops to 13.0 Volts (at the battery). Reading aren't any better even at 2500+ RPM (verses idle). I can drive the car all day long without problems but as soon as the headlights go on it runs off of the battery. Don't know what kind of alternator it is but I believe the builder said it was off of a foreign car & it's really small physically. The alternator mount is homemade (not by me) & leaves a lot to be desired. With the belt the builder put on their the belt hits a water outlet & wears through in time. I don't want to use this belt. With the next size smaller belt on it is a real pain to get on. You have to practically pry it on. I'd like to go to a bracket set up that is sanitary & easy to change belts on. Oh, the alternator was rebuilt by a local guy who has a good reputation but must have done something wrong as it only worked for awhile. So anyway, I don't want to mess around with taking it back to him. I'll just get a new one. So this is what's up... I asked about a GM alternator cuz that's what the Hot Heads bracket takes but after looking again I don't think the upper mount will work. But on the bottom with the Hot Heads mount might work on the right side of the engine. There's no reason I can't mount it on the right side is there??? Thanks! Bill ps, yes the title of the post was misleading.
Check out all these search photos for alt and mount options. https://www.google.com/search?q=32+...ih=752#tbm=isch&q=32+ford+392+hemi+alternator
I would take your alt. to a repair shop and see if it is working right. I would think that it should keep up with the lights. Most of those small alt. are pretty high amps unless it is something off of a forklift or lawn mower. There are no new cars that you can only drive in the daylight!
First off your car should not be running off the alternator. I am curious what you are running for lights and how you have them wired. if all you are running is motor and lights a stock 65 amp alternator should run it just fine. I have 65 amp GM alternator that I have modified to put out 110 amps. I don't need that many amps but when the alternator took a dump in the '90s it was cheaper to rebuild it as a 110 amp unit then to buy another one and I needed a tech article for a magazine that I was working for. Anyway getting back to it what on earth are you running for lights, it sounds to me more like you have wiring issues than alternator issues.
Are you using a 1 wire alt? Maybe you should go to a 3 wire with a sensing wire back to the ignition switch or to where most of the power is drawn from. From the Mad Dog site: The other of the two plug-in wires at the SI series alternator is the “voltage-sensing” terminal for the voltage regulator. Through the sensing-wire, the voltage regulator monitors electrical system voltage and makes adjustments to alternator output. The regulator will adjust alternator output as needed to maintain the place where the sensing-wire is routed (at about 14.2 volts). And the sensing-wire can be routed to a place remote from the alternator (downstream). This “remote voltage-sensing” feature is often a big advantage when running with a factory type wire harness from the Muscle car period (60’s and early 70’s period cars and trucks). Then the alternator output will be adjusted according to what goes on far downstream from the alternator–at the main power distribution junction, which operates the whole car plus charges the battery!
Amps isn't the issue about your dim lights as mentioned before. Back to original question. What does your electrical system consist of ? Example - Radio, Amp for Radio, Power Window, Power Seat, Air Conditioning ? This is what will determine your amp requirement. Back to Head Lamp issue. Primer wiring (main feed to everything) and how it's branches off and size wire will affect this and not the alternator. Test voltage at the alternator. If it it differ's alot at another source (battery, fuse panel, switch, ect.) then your wiring is in question.
If the output does not improve with rpm I would look at belt slippage. Spray a little belt dressing on it and see if the voltage climbs. Belt dressing is not a fix but can help in diagnosis.
Lots of good input here, I will add. Get an amp clamp meter and see exactly what your system draws. That will tell you what you need. You said the belt was hard to tighten. Is the belt really tight? Chrome pulley? Etc. Best of luck.
he says he is putting out 14volts with the car running. I hope it is not going to put out any more then that.
GM was at something around 80 amp alternator in the 1980s but still using a singe V belt. It did not work as the car got miles. The belt would slip without making any noises at all, with all accessories running, and was often diagnosed by some shops as a bad alternator. On those GM's the only belt that would hold up over time, was I think Dayco? Top-Cog with cogs at the top flat side. The alt pulley was worn quite a bit at 50,000 miles. They would put out 14.2V at idle with everything shut off, but volts took a dive when things were turned on. Big trucks with 100A alternators always ran twin V belts back then. I'd get the alternator bench tested at a shop, also replace pulley if bad, then do the system draw test to see what amps you need, like mentioned. .
Put your meter on the alternator. It sounds like a wiring problem, with too much voltage drop between alternator and battery.
Without a load I'm guessing the voltage regulator is limiting the it at 14v but with a load it can't get there even at 2500 rmp ether its the alternator or the belt
Thank You Everyone for all the replies! It used to charge just fine so I don't think it's the headlights or wiring. Unless it's some kind of new problem with the wiring. I'm running head, tail, brake & turn lights, electric fans & fuel pump, windows, wipers & a cigi lighter so I can charge my phone. The radio was hooked up when I had a small block Chev in it but with the Hemi it's pretty loud so not hooked up. In fact, I'm going to just take it out... The belts still squeak even though I've squirted tons of that spray liquid on them. Belt is hard to tighten but it is tight. Single pulley just runs alternator & water pump. I'll put the meter on the alternator to check output & then take it to Auto Zone & have it checked. It's a foreign car alternator. Toyota or Honda I believe. I can also get a 'amp clamp' to check system draw. Not sure if it's one wire or there but I'll check tomorrow when I can work on it. Wow! Thanks Again! A wealth of knowledge on the boards! Bill
Oh, I read something where the more the output of the Alternator the hotter it runs. So my idea of just getting the highest output alternator there is isn't a good idea....
Rechecked the output at the battery again & it shows the alternator not charging. Took it off & I'll take it to Auto Zone tomorrow to get checked. And it's a one wire.
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