#1 - If the main fuse (the 80A one) is blown, there will be no power to anything, you won't get the vehicle started, and it won't charge the battery because the battery isn't connected.
#2 - None of the sensors act as grounds - if the "heat sensor" has a ground, it is ground for that sensor only.

12V engine off, 13V engine on, lights, heater & radio on sounds good.

Just stating the facts ...

ECU is aware of missing grounds, ether because of the presents or absents of data it receives.  Some grounds are critical.

First - if the ECU detects a missing ground (which it can do based on the sensor input being outside of the expected parameters) it will set a check engine code, and then, where possible, substitute predefined data for the erroneous data, to permit engine operation.

Second - the ECU does not control the charge system, at least not on this generation of the vehicle.

NONE of the ECU grounds have any impact on charge system operation, however charge system grounds may impact ECU operation.

Quote:
NONE of the ECU grounds have any impact on charge system operation, however charge system grounds may impact ECU operation.

Yes the cart can push the horse.

Suzuki does, I think you know this, have ECU controlled Alternators.

Well, all went well today, with daughters car, so I still have my Hero status.

I'm well aware of the fact that some Suzuki vehicles have ECU controller alternators, that's why I went to the trouble of qualifying the statement - not on this generation of the vehicle - I own a Suzuki with an ECU controlled alternator, in fact, one of the first generation of Suzukis to use such an alternator.

As far as the cart pushing the horse - if you have the evidence I'd love to see it - I'm always willing to learn something new - in case it hasn't occurred to you, I am quite familiar with the charge systems used on these vehicles and it is identical to that used on the carbureted versions of the vehicle (they do exist, just not in your part of the world) - when I say the ECU grounds have no impact on the charge system, it's because I know, from experience, that the charge systems will work, whether or not there is an ECU or an ECU ground.

The charge system is actually completely independent of the vehicle's other electrical systems requiring only a 12V source for excitation and that is taken from the ignition for convenience - you can spin that alternator with a belt from any rotating power source (for example a windmill) and it will charge a battery, no vehicle required - by the way - you can also use the ECU controlled alternators like this, in the absence of an ECU, they operate like any other alternator.

Kudos on the hero status - it's important - I have three daughters

Attention fordem,  We were at the mountain spread and I brought back related service manuals.

I found in 1997 Tracker service manual a caution against disconnecting ether battery terminal while engine is running.

The car ran well for, I think a month or month and a half~I'm hoping that means no problems were caused.
The condition of NO CHARGE showed when again there were damp/wet conditions.

I have yet to have the sidekick brought to this location as there is record snow in the mountains where the car in now.

How is the alternator belt tension?  Have you checked for a parasitic leak on the battery when the engine  is off (key off & removed)?

Attention fordem,  We were at the mountain spread and I brought back related service manuals.

Let's start on a fresh page...

You have a new battery and a new alternator, what makes you think there is a "no charge" condition?

By the way, I did see your other thread, I chose not to respond hoping you would get opinions from other folks.

How is the alternator belt tension?  Have you checked for a parasitic leak on the battery when the engine  is off (key off & removed)?

The belt alternator tension was good. I haven't checked for leaks. The charge seem to be there or not, and may be subject to weather. The alternator has been checked and passes. Hoping to have the car here in a few days, weather permitting.

Quote

Attention fordem,  We were at the mountain spread and I brought back related service manuals.

Let's start on a fresh page...

You have a new battery and a new alternator, what makes you think there is a "no charge" condition?
By the way, I did see your other thread, I chose not to respond hoping you would get opinions from other folks.

Greetings, Thanks for coming by, RE: No Charge~ Testing, with volt meter, with engine not running ~with engine running I expect to see the voltage increase as it did when the Alternator was supplying charge. The Alternator may be sound but there is no sigh at the battery.
Checking for open circuit, loss of ground or blown fusible link or what ever will have to wait for the car to come to me.
You, will be surprised, I think, at the amount of snow where the sidekick sits!

Richard

uhmm ya that's a lot of snow ......... west coast Canada is where I live (Chilliwack) and in 36hrs have over 2'. so working on problem solving is from the warmth of the couch lol

On my last trip, my battery light came on just at dusk and still having two more hours to drive, my battery wasn't going to make it.  So I stopped at Autozone and had a test ran on alternator, which came out good.  After shutting down motor, I noticed that when the counterman was disconnecting from negative post that the battery clamp moved.  After snugging up the battery clamp, Battery light went out when I started it back up.  Still charging and running good.
A loose wire Hot or Ground?

Thanks BRD HNTR~Got those tight.
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Well, at long last: The Pink 77 Sidekick is outside here at the lower ranch.
Battery engine NOT running Voltage 12,48

engine running: Voltage at battery 11.78 and will continue dropping if engine.

Question: Does the ECM control alternator output in any way?

Thank you

Richard
I tested the wires both ground and positive battery to Alternator almost no resistance.

*  I just found this post by fordham:
Second - the ECU does not control the charge system, at least not on this generation of the vehicle.



If that is true, than though the Alternator tested  OK a few weeks ago, I may grudgingly remove the damn, or darn, thing and have it retested  Unless one of you gent has an idea of what you would test before testing the Alternator again. 

First - does the charge light come on when the ignition is switched on and go out after the engine starts?

Second - there is a two wire plug that connects to the alternator - the wires should be black/white & white/red - connect the meter negative to the battery negative and back probe the wires with the ignition on and the engine both off and running - what voltages do you get?

Greetings fordem. Yes, there are two wires going to the Alternator on a single plug. The power light comes on and then goes off. I didn't see an idiot light of any other description.

I had told the girls that it isn't impossible that the voltage regulator has blown.The girls were pushing me to have the Alternator checked again, I gave in and she took the Alternator into NAPA
in Silver Springs, he, the parts fellow put it on the tester and said: "NO VOLTAGE OUTPUT" She ordered one that will be in tomorrow.

I'll be in the mountains tomorrow~wife will take the Alternator in to be tested in Carson City (just to be sure) when I return I'll install hoping for the best.

fordem, thanks for coming back on this. If the New Alternator doesn't work we'll have to find a way of blaming you~Just kidding.

I'll come back on to tell the outcome.

Richard

It's snowing in the Sierra Nevada as we speak, they claim 180% normal, I don't know about that, lived there for a lot of years, but it is nice to have the big snow to make up for some three years of drought.