[lowmileage]

I only take the car out at night 2x per year. On last years nightly (actually early morning) jaunt I noticed (with the lights on) a very faint glimmer of red light from the dredded Alternator light. None the worst for wear, after driving like that for a few hours I didn't notice any dimming of the headlights that would indicate a battery run-down condition.

Getting back to things a year later for this years early morning run, I installed a Voltmeter. What I notice is that without the lights on, I'm running 13 volts or a bit more - I have the voltmeter in a fairly obscure , but functional location. With both pair of lights on (without the "brights"), it goes to 12 or a bit more. With the brights, it's below 12 with a very, very faint Alternator glow. According to bills left me from the PO, I'm supposed to have a 65 amp Alternator. The Alternaor has the sticker "PB041" on it. Shouldn't I be running at or close to 14 Volts without anything and like 13 Volts with lights?
Cleaned fuse panel, replaced all fuses, battery is of good quality and under 3 yrs old, cleaned the alternator (red) to battery wire connection etc. I even put a "better" battery in there for comparative purposes and got the same results to eliminate the battery as being at fault. Lighting is nothing exotic (power hungry) - Wagner halogens.

 

[Tifosi]

Book here (for 55 amp internal regulator) says 3000rpm no load should produce 13.7 - 14.7V.

Full load (lights and everything going) should not drop below 12V.

It doesn't give any spec for idle speed output, but I can offer that mine puts out just about 14V with no load at idle, (Bosch 65 amp internal regulator), and never drops below 12 1/4V when things are turned on.

Book also suggests testing voltage at battery terminals rather than anywhere else as that's where the voltage has to get to when it's all said and done. (I've got a gauge hooked up in the conventional fashion too BTW)

How's your ground wire/strap and alternator junction contacts?

 

[lowmileage]

I cleaned up all Alternator connections, fender relays and other connections. New battery ground strap attached to cleaned (no paint) body panel. I'll take a better look at the underbody ground but I visualized it and it appeared good. I also try attaching my meter to the battery with the lights on and see how it compares to the gauge. Thanks Tifose

You can't test Alternator output can you with a Multimeter?

 

[Alfacliff]

There is also the large but not the largest red wire connected to the starter solenoid, corrosion on this wire, which connects the rest of the car to the battery has got a lot of bad problems. the battery goes to the solenoid, then back to a terminal block usually on the left front, on my 74, under the battery, then to the fuse block.
cliff

 

[lowmileage]

There is also the large but not the largest red wire connected to the starter solenoid, corrosion on this wire, which connects the rest of the car to the battery has got a lot of bad problems. the battery goes to the solenoid, then back to a terminal block usually on the left front, on my 74, under the battery, then to the fuse block.
cliff

I replaced the postive cable from the battery to the starter last year, so that one is OK. I will look at the solenoid wiring also tonight. Thanks Cliff.

 

[Tifosi]

You can't test Alternator output can you with a Multimeter?

Ummmm....... I dunno.

It would seem that you could, but how to go about it is beyond me.

If I had to take a guess it would be to unhook the alternator from the junction block, connect that wire to the + on the multimeter, the - to the junction block, and set meter for big amp DC voltage.

Though with the small gauge wires on most multimeters, that may lead to melting down the wires or simply blowing the meter up.

Yeah, prolly your best bet would be to have someone that actually knows how describe it

 

[Alfacliff]

if you hook up an ampmeter to the alternator and check the current, it will tell you if the alternator is working. there are clamp on ampmeters that work on dc, most only work on ac. a simple test is for voltage drop from fuse box to battery or alternator. did you replace both wires, the one from the battery to the solenoid and the one from the solenoid to the terminal block? about a number 6 or so, a little smaller than the battery, but larger than most other wires in the car.
cliff

 

[lowmileage]

if you hook up an ampmeter to the alternator and check the current, it will tell you if the alternator is working. there are clamp on ampmeters that work on dc, most only work on ac. a simple test is for voltage drop from fuse box to battery or alternator. did you replace both wires, the one from the battery to the solenoid and the one from the solenoid to the terminal block? about a number 6 or so, a little smaller than the battery, but larger than most other wires in the car.
cliff

No, didn't replace that one.

 

[Alfacliff]

thats the one that sometimes gives trouble, either at the crimped ends or corrosion.
cliff

 

[lowmileage]

thats the one that sometimes gives trouble, either at the crimped ends or corrosion.
cliff

Consider the connection replaced and the wiring condition checked! Thanks

 

[Alfacliff]

it always seemed silly to me to run the battery to the solenoid then back under the battery to the terminal strip that feeds the fuse box.
cliff

 

[lowmileage]

There is also the large but not the largest red wire connected to the starter solenoid, corrosion on this wire, which connects the rest of the car to the battery has got a lot of bad problems. the battery goes to the solenoid, then back to a terminal block usually on the left front, on my 74, under the battery, then to the fuse block.
cliff

Cliff,
That wire connection was good. I "messed" with it last year when I had to do the wire modification on the Cold Start of the Spica when the starter kept on running even with the key off. More to follow

 

[lowmileage]

Book here (for 55 amp internal regulator) says 3000rpm no load should produce 13.7 - 14.7V.

Full load (lights and everything going) should not drop below 12V.

It doesn't give any spec for idle speed output, but I can offer that mine puts out just about 14V with no load at idle, (Bosch 65 amp internal regulator), and never drops below 12 1/4V when things are turned on.

Book also suggests testing voltage at battery terminals rather than anywhere else as that's where the voltage has to get to when it's all said and done. (I've got a gauge hooked up in the conventional fashion too BTW)

How's your ground wire/strap and alternator junction contacts?

Well I made progress on one thing last night (couldn't get the Jeep's 02 sensor done though). Even though the Alfa's ground strap connection looked good on the frame, I took the bolt off. What I found in that when they painted the frame, they didn't scrape the paint off where the ground strap attached. So I had ground only on the bolt threads going into the body. After I corrected that faux paux, I started the car. I then tested voltage at the battery and it was 14.2 . The Voltmeter installed in the car hooked to an unused (mystery) wire under the dash was reading about 3/4 volt less (I will eventially hook the connection direct to the battery). I immediately noticed when I put the lights on that the voltmeter in the car hardly moved . It stayed above 12 (meaning then close to 13 at the battery) with all lights on including the brights.. Tifosi, you are just so

 

[Tifosi]

Sweet.

Glad to be of service.