Electrical Gremlins: Ignition and Temp Gauge

[LeonV]

The BASIC problem is that you are using a later year alternator in an earlier year wiring circuit.

You can go ahead and use all sorts of fancy instruments, data, interpolation of results, statistical analysis and all the fancy terminology you want, but you are still going at this bass ackwards.

The reason you're not showing a charge through the Ammeter is basic. By removing the original Voltage Regulator, which included the Ammeter in it's circuitry, and using an internally regulated Alternator (with the Alternator Adapter) that does NOT use it, you've eliminated the Ammeter from the circuit.

2¢

E

That is the correct answer, and what I was going mention as well.

[jfa.series1]

Enrique - thanks for the for the straightforward clarification, nice and simple. Is there a fix for this situation? I want to keep up with the state of the electrical system.

Jim

[EScanlon]

Not that I recall from all the years of reading the mods we've done to these cars.

Wish I could tell you differently.

E

[Arne]

The reason you're not showing a charge through the Ammeter is basic. By removing the original Voltage Regulator, which included the Ammeter in it's circuitry, and using an internally regulated Alternator (with the Alternator Adapter) that does NOT use it, you've eliminated the Ammeter from the circuit.

That is the correct answer, and what I was going mention as well.

I beg to differ, guys. The ammeter is not removed from the circuit when you upgrade to a later internally-regulated alternator. My ammeter works fine with the 60 amp '83 ZX alternator w/diode adapter. The alternator upgrade had no effect on the ammeter function at all. In fact, watching the ammeter made it obvious that the later alternator/regulator was much quicker to respond to load changes - the ammeter doesn't jump around when the load is stable.

My ammeter does show a constant positive charge when the lights are on, but that is because of the headlight and parking light relays I have installed, not because of the alternator change. The relays move the lighting draw or load off the normal circuit, instead drawing directly from the battery. The ammeter can't see the draw from the lights, but does see the increased output from the alternator to match the draw.

Indeed, there is no easy way to remove the ammeter from the circuit at all. All fused power passes through the ammeter before it it is switched or goes to the fusebox. If your electrical devices work (clock, lights, horn. etc.), the ammeter is still in the circuit.

So why is there no charge being shown? I'm guessing it's because there is no charge. As a rough guess - since you did get a modest charge showing with the original regulator in the circuit, I suspect the internal regulator in the ZX alternator may be faulty.

[SteveJ]

Arne is correct.

The battery still feeds on the positive side of the ammeter, and the alternator feeds on the negative side of the ammeter. Taking out the ammeter will more than likely kill all of the circuits fed by the large white/red wire.

There is a test to verify this. Take out the ammeter and turn the key to Start. If the solenoid engages, then Arne and I are wrong.

Given that fact. Jim, here are some more diagnostics for you. (See this description of the alternator mod for more information on where the wires land.)

1. As I stated before, if you do not see a voltage of at least 14 volts at the battery with the car around 2000 to 2500 RPM (It should be more along the lines of 14.5 or so.), then the battery is not charging.

2. With the car off, you should be able to check the wire for full-field bypass.

Measure at the yellow wire at the alternator to ground. You should have 12VDC.

3. Next check the ignition signal.

Put the key in the RUN position. If you measure voltage from the white/black wire at the alternator to ground, you should have 12VDC.

If you don't have charging while the other tests pass, your alternator is bad. If either tests 2 or 3 fail, you have wiring issues.

[jfa.series1]

Arne and Steve,

Thanks for the clarifications and great instructions on testing. I'll get into that this week. BTW - I do have the headlight and turn signal relay kits installed.

Jim

[Arne]

BTW - I do have the headlight and turn signal relay kits installed.

Jim

Here's a quick and dirty test then, Jim. With the engine running, note the ammeter position and then turn on the headlights. If everything is working properly, the ammeter should swing to the plus side. Probably close to 15 amps. If it doesn't move to the plus side, there is something wrong with the charging system - either the alternator or the internal regulator. Edited September 5, 2011 by Arne

[EScanlon]

I stand corrected.

I will have to find the discussion that was posted some years ago, but my recollection was that with the internally regulated alternator, the ammeter was only reading the discharge occurring in the system and not the charging. The discussion went on to say that the ammeter was essentially removed from the circuit.

My car does not have the internal regulated alternator, I still have the original and the regulator. They work fine. As a result, I fell prey to quoting from older messages rather than cutting and pasting the old posts or links to them.

But I'd be interested in finding out the result of whether or not the car will start with the ammeter disconnected. That would confirm a wiring schematic discrepancy as either correct or incorrect but yielding what it should be diagramed as.

FWIW

E

[LeonV]

I stand corrected.

I will have to find the discussion that was posted some years ago, but my recollection was that with the internally regulated alternator, the ammeter was only reading the discharge occurring in the system and not the charging. The discussion went on to say that the ammeter was essentially removed from the circuit.

My car does not have the internal regulated alternator, I still have the original and the regulator. They work fine. As a result, I fell prey to quoting from older messages rather than cutting and pasting the old posts or links to them.

But I'd be interested in finding out the result of whether or not the car will start with the ammeter disconnected. That would confirm a wiring schematic discrepancy as either correct or incorrect but yielding what it should be diagramed as.

FWIW

E

I second that! My external regulator is working fine. I thought I remembered reading/seeing that the internally regulated units don't excite the ammeter, but I'll concede to those that have actual experience with this.

[Arne]

The lighting relays cause a change - the ammeter only sees the charge, not the load. So when the lights are on, the ammeter shows well to the plus side. But the actual changes to the wiring to use the internally regulated alternator are simply to install two jumpers (one w/diode) to complete the regulator wiring circuits. Doesn't affect the current flow in any way.