Quick alt. question(UPDATE*FIXED*)

[BobK]

71 Blazer with a 140 amp 3 wire alt.
Noticed my lights are REAL bright and my amp gauge is peged to full charge when I'm on the gas(right in the middle at idle).

It's prob. the voltage reg. right?

I have'nt taken any reading with my digital volt meter yet as it's dark out now.

I Just wanted to get some opinions before I statred to diagnose tomorrow.

Thanks in advance. /forums/images/graemlins/peace.gif

 

[cybrfire]

Re: Quick alt. question

I think your on target there.

 

[BobK]

Took some reading with my volt meter this morning...21 volts at idle /forums/images/graemlins/yikes.gif

Well,had to go to 3 different parts stores to get it checked and even then they told me it was toast.It wasn't toast....I replaced the regulator and all is good.
14.3 volts at low idle with heater on high,high beams on,55wt driving lights on, stereo on,and windshield wipers on. /forums/images/graemlins/grin.gif

Sorry to any parts guys on the board but boy are most of them idiots

 

[dyeager535]

What kind of alternator is it? Aftermarket or stock application?

With that kind of output at idle, sounds like an aftermarket of some type to me.

All the posts lately of alternators, if someone is looking for something specific, more details about alternators used can always help.

 

[BobK]

Ya it's a Summit brand 140 amp alt.It's actually made by PowerMaster.

Summit sell's it as a one wire alt. but according to PowerMaster(I called them) if you remove the rubber plug that blocks off the 2 prongs that the factory alt.'s use it can be used as a 3 wire alt.

They test them before they leave the factory and it comes with the test info. attached to the alt.
Mine was 90 amps at idle and 163 at highway speeds. /forums/images/graemlins/thumb.gif

Oh ya,I had my two 14" electric fans going as well.

 

[Triaged]

You still have the 140A alt run through the stock ammeter? I have heard that that isn't a good idea with anything over the 35A stock alt. I will be ditching mine (in favor of a voltmeter) as soon as I put in my 135A alt.

 

[Tybee]

[ QUOTE ]
You still have the 140A alt run through the stock ammeter? I have heard that that isn't a good idea with anything over the 35A stock alt. I will be ditching mine (in favor of a voltmeter) as soon as I put in my 135A alt.

[/ QUOTE ]
Mine caught fire with the stock alt.

 

[84_Chevy_K10]

All of this is why I don't use an ammeter.

 

[BobK]

Yup.I've had the factory ammeter working since I got the truck(5 years ago).No fires,although I did replace the circiut board in the back of the gauge panel when I got the truck.

I thought the factory amp. gauge only measured charge or discharge conditions,not actual amps. /forums/images/graemlins/confused.gif

Anyhow the gauge works well.I've rewired my truck and am confident that that gauge does NOT see anything near the amperage I mentioned.

One end from the gauge to the alt. and the other side of the gauge to the battery.
If that samll 18g ammeter wire was actually accepting or carrying the full 90-140 amps that thin 18g wire would burn up before catching the gauge on fire....you'd think.

 

[BobK]

I got this from MAD Electrical's site.

Our amp gauges are "shunt type" they don't carry the full amp loads of older systems.

[ QUOTE ]
GM also up-graded their system long before the Dodge Boys. When GM introduced the alternator with ’63 models, it was controlled by a more complicated but more efficient voltage regulator system. And the new GM system could support a warning light at the dash. The warning light was often standard equipment and the gauge was an option. GM vehicles built with the gauge option also had a more modern design of AMP gauge at the dash. The newer AMP gauge was a remote shunt type design–a length of the battery charging wire in the under-hood harness served as the shunt. The dash gauge and related wiring no longer handled heavy current load. Same with Ford in ’65 and newer model cars–the Ford system could work with a warning light at the dash, and cars that came dash gauges had a remote shunt type amp gauge.

[/ QUOTE ]

 

[4xcrazy]

All of this is why i plan to use a secondary alternator dedicated specifically to all the aftermarket mods, lights,fans,amplifiers, whatever, and keep all factory items using stock factory hardware, no guessing, no worrying. WOOP WOOP

/forums/images/graemlins/pimp1.gif/forums/images/graemlins/waytogo.gif /forums/images/graemlins/woot.gif /forums/images/graemlins/woot.gif /forums/images/graemlins/waytogo.gif /forums/images/graemlins/pimp1.gif