Upgrading Alternator

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jhdeval

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So today for the first time I think I found why my wipers are not working. With the key in ACC position the wipers work fine but driving they don't work. Well today I noticed the Ammeter would drop to near 0 when they would sweep across the windshield. I also noticed at night my ammeter would show low with the lights on. So I am thinking my Alternator is not providing enough amps. Does anyone have an model/item number for an Alternator that fits but provides more Amps?
 
The wipers should work even if the alternator doesn't. It would just take juice from the battery until the battery went dead. Sounds like you have some wiring or switch problems to me. Check your output on the ignition 2 terminal of the ignition switch. Do the turn signals and heater motor work ok?
 
The problem is that there is not enough amps flow at an idle to supply the lights, brakelights, turn signal all at the same time and have them all work at full speed or brightness.
You know how when you speed up from a stop or rev the engine, everything seems fine?
The alt needs rpm's to charge well, so I don't think upgrading your alt is goin to help.
Have you noticed how your turn signals slow down at a stop?
Same thing.
Unless you upsize all the wiring involved your not going to change much.

I have actually considered using an electric motor to run the alt at rpm to overcome that since they seem to only need about 1,500 rpm to charge at full output.
Also, it wouldn't matter if you had to use a motor that was drawing a fair amount of amps either if you alt was putting out 70 amp all the time right?
 
The reason I think my alternator is at fault is because both driving and idle the wipers don't work right only with the ignition in ACC (battery only).
 
green1 I can not drive the car in Acc. But when I am stopped in the Garage trying to figure out the issue rather then letting the car idle the whole time I tried it in Acc as well as trying while driving the car.
 
Put your wiper motor on a relay and use your original wiper wireing to just turn on the relay. That way you are pulling the volts right from the battery, not through the harness. If that works out for you, make relays for your headlights too. You'd be amazed on what 2 volts does to the output of your lights. Your original alt is about 35A. Get yourself a rebiult tested alt, and check your old points type regulator. They make electronic ones now that look like tht old ones, or you can upgrade to a isolated field squareback alt and electronic regulator. The original blue wire goes to the 1st (right) terminal of the electronic regulator and then on to the first field of the alternator, the other terminal of the regulator (bottom of the triangle) goes to the second field. They put out about 2X the amps of the old round ones. Might want to consider upgrading your main run to the battery to an 8g wire. That or a smaller pulley on the alt and a larger pulley on the crank.
 
You can test (basically) the alternator buy pulling the battery cable off while the car is running.
I think I see where you are going with this maybe.

When the engine and everything else that is on while running the power is too low to run the wipers well?
Sorry if I'm not understanding.
 
Basically the wipers go but they stutter (Start and Stop) across the windshield. While they stutter across the windshield I noticed the ammeter on the dash would drop significantly. I ordered the relays to move the headlights. I will see how that works as I planned that anyway. If that helps but not fix I will move the wiper motor also.
 
jhdeval said:
Basically the wipers go but they stutter (Start and Stop) across the windshield. While they stutter across the windshield I noticed the ammeter on the dash would drop significantly. I ordered the relays to move the headlights. I will see how that works as I planned that anyway. If that helps but not fix I will move the wiper motor also.
Click to expand...

It could be that the wiper motor is dragging a lot due to lack of lube on the stator bushings too.
Just a thought.

Autozone has 30 amp relay's for about 8 bucks.
 
allelectronics.com has them for 2.50 and the dual relay socket for a couple of bucks. I ordered 4 relays and two duals for future expansion. Including the wiper motor if it comes to that.
 
TrailBeast said:
You can test (basically) the alternator buy pulling the battery cable off while the car is running.
I think I see where you are going with this maybe.

When the engine and everything else that is on while running the power is too low to run the wipers well?
Sorry if I'm not understanding.
Click to expand...
Don't EVER test an alternator this way. It's likely you'll blow a diode doing it. Put a meter on it to test it.
 
But if you don't have a meter,,,
Been doing it this way for probably 45 years and I have never blown a diode.
Have you ever blown one by doing it, or just heard that from somewhere?



cudamark said:
Don't EVER test an alternator this way. It's likely you'll blow a diode doing it. Put a meter on it to test it.
Click to expand...
 
I would never test an alternator that way. I do have a meter and know the proper way to test it. The only reason I have not tested it is because I was not sure where the problem was I just noticed today the ammeter issue.
 
You are all overthinking this

FIRST all these cars logged millions and millions of miles "back then" with nothing more than about a 35 amp alternator and they worked "OK" and by that I mean, yeah, the lamps might have dimmed at an idle, but hey, HOW LONG DO YOU DRIVE THE CAR when it's idling?

The wipers certainly didn't stop working just because the alternator was not keeping up!!!

HERE is your possibilities:

SOMETHING is wrong with your present alternator, that is, you have one or two bad diodes, some bad windings, and is not CAPABLE of putting out ORIGINAL rated output

Second, the age old "bulkhead connector" or other related trouble.

The way you describe this problem, I would not be suprised if the IGNITION SWITCH is not the problem

Putting a BIGGER alternator on the car IF and (probably) when you have a wiring/ switch/ fuse panel problem, will only make it worse. Can you spell "let the smoke out?"

SO do this first:

ONE make sure the battery is charged and find someone to LOAD test the battery. This is for just general "good," not necessarily part of this problem

Inspect and CLEAN the battery terminals. Make sure the main ground is to the engine block, and make sure there is at LEAST a no 10 ground from the block or battery to the body. If any doubt, add another

Take apart your bulkhead connector, inspect, and clean. I'd bet money this is an issue

Then get down at the fuse box, and measure the voltage on the SWITCH side of the fuse key on, engine off, wipers/ radio/ lights/ etc off. Then turn on the wipers and measure the voltage on BOTH SIDES of that fuse

Then go up to the battery positive and clip your meter to the battery post, and make the same measurements, IE wipers on, wipers off at the battery

Post those readings

Read this article about bulkhead connectors:

http://www.madelectrical.com/electricaltech/amp-gauges.shtml

more good articles:

http://www.madelectrical.com/electrical-tech.shtml
 
Okay first thing I did was disassemble the bulkhead connector on the engine side and cleaned the connections. I also cleaned all the fuses and connections but none of the fuses affected the wiper operation. Then I tried the wipers same issue. Next I took the voltage measurements.

All measurements taken with key in ACC. Hopefully this will help because I am at a lose what to do next. I don't think it is the motor but never know.

Top side of fuse: 12.04
Bottom side of fuse: 12.04

Top side of fuse wipers on: 8.8
Bottom side of fuse wipers on: 9.5

Battery wipers off: 12.3
Battery wiper on: 12.0
 
You are lucky that on your car, the alternator current is routed through solid lugs instead of thru the connector blades ("56 series terminals") of later models. The later have a tendancy to melt the bulkhead connector. If you disconnected the wires, sanded connections and re-attached w/ silicone grease coating, it should be fine.

You shouldn't get a 2.8 V drop from the battery to the ACC fuse from just the wiper current. Besides the bulkhead lug, that flows thru the ignition switch to the ACC terminal, which should be a 12 awg black wire at the switch. Remove your switch and sand those terminals. The battery feed is a 12 awg red wire. If that doesn't help your switch may be bad inside. Above is based on the wiring for my 65 Dart.

The 0.7 V drop thru the ACC fuse sounds a bit high. Remove and sand the connections. Perhaps the wiper motor is drawing too much current. A stalled motor can draw a lot of current, making it over-heat and melt windings. Try running ~14 awg jumpers straight from the battery to the wiper motor and see if it jitters w/ a full 12 V supplied. If so, the motor is probably bad or too much friction in the linkage and pivots.

As others said, the alternator is not the problem. You should be able to run the wipers fine just off the battery. Your battery is barely drawn down by the wiper current. A fully charged battery should read ~13.4 V, so either it isn't charging fully or your multi-meter is off. I have the factory 30A alternator in my Newport and it keeps up fine w/ electronic ignition, TBI fuel, and headlights on dark winter days, and I only drive 4 miles between starts plus many 1 mile trips around work. The later square-back alternator puts out more current and is direct mechanical fit, but you need to ground one field terminal or switch to the electronic regulator (better). Some install a GM-type "1-wire" alternator, which cleans up your wiring, but requires mounting spacers and a special tensioner arm.
 
You're on the right path

Either the wiper motor is drawing a hell of a lot of current (which I would think would blow the fuse) or else the accessory side of the ignition switch has a drop

The basic current path is from the battery, through the firewall, to the ammeter circuit, to the ignition switch, and to the accessory buss on the fuse panel.

With what you've measured so far, I'd try to get a clip lead up on one or the other of the ammeter terminals and measure the voltage there with wipers on/ and off

Better yet, yank out the ignition switch and measure the RED and the BLACK with wipers on and off
 
Ok so I just finished moving the headlights to relays and WOW they are notably brighter but that did not resolve the wiper issue. So I agree it looks like the ignition switch.
 
TrailBeast said:
But if you don't have a meter,,,
Been doing it this way for probably 45 years and I have never blown a diode.
Have you ever blown one by doing it, or just heard that from somewhere?
Click to expand...

The newer your car, and the more electronics on board, the more peril you put the system in. I won a sizeable bet, back in the 70's about this

When you lift a battery connection on a charging / running system, a voltage spike up into the 100 volt area appears on the system. That spike is perfectly capable of damaging electronics systems.

YOU WILL NEVER FIND this so called "procedure" in any book, manual, or classroom.

Moreover, it proves NOTHING. That's because this so called 'test' does not show what the alternator can actually output. It could ALREADY have 2 or 3 open diodes and be "sick" but working enough to pass this "test."
 
jhdeval said:
Ok so I just finished moving the headlights to relays and WOW they are notably brighter but that did not resolve the wiper issue. So I agree it looks like the ignition switch.
Click to expand...

OK how do you deduce this? Have you checked AT the switch? Do other accessories "die out" (heater, radio, ??) in the same manner as the wipers?
 
The heater does not die but I can hear the fan spinning faster in acceleration versus idle. I have not noticed the radio dieing but on the same token I hardly use it. The wipers are the only electric system in issue but I have cleaned all the connections. I cleaned and re greased the arms and connections.

I have tested the wiper motor and it works as expected when given a raw 12 volt supply.
 
67Dart273 said:
The newer your car, and the more electronics on board, the more peril you put the system in. I won a sizeable bet, back in the 70's about this

When you lift a battery connection on a charging / running system, a voltage spike up into the 100 volt area appears on the system. That spike is perfectly capable of damaging electronics systems.

YOU WILL NEVER FIND this so called "procedure" in any book, manual, or classroom.

Moreover, it proves NOTHING. That's because this so called 'test' does not show what the alternator can actually output. It could ALREADY have 2 or 3 open diodes and be "sick" but working enough to pass this "test."
Click to expand...

You would lose the 100v bet on newer alternators, but the damage is spectacular. With the rise of electronics in vehicles, alternator manufacturers began putting avalanche diodes in alternator rectifiers. Yep, just big 25v Zeners. So when you full field a newer alternator with no battery to sink the output current, the diodes conduct @ 26v, and short all of the phases together & to ground.

Alternators rebuilt in recent years may have avalanche diodes installed. Rebuilders are not likely to carry two different parts, when one will serve both applications. You would save the onboard electronics, but the dead short on the alternator output gets messy quick. As a bonus, if the diodes fail shorted you have a direct short if you hook the battery back up as well.

So, yeah don't pull the battery cable off of the battery with the engine running.

.
 
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