why the dim red light?

[Ray Morley]

I just replaced the fan belt and its at the proper tightness.

When you key the ignition to the 'on' position the alternator light is full bright red as normal. After you start the car the light continues to glow red but very faint. Revving up the engine has no change to the intensity of the light.

My Kadett Rallye also has a separate alternator guage and its not showing any problems at all. If I turn on all of the electrics the guage shows a slight negative indication then returns to the center.

Any ideas? This is a new problem since I replaces the fan and belt yesterday.

Could I now have a voltage regulator issue?

[Anonymous D]

I believe that if you search the archives here, you'll find details of a voltage test at the battery terminals, that will indicate if you are receiving a proper output from your charging circuit.

[namba209]

Here's a quick primer on the charging circuit. The light in the ammeter sends a signal voltage to the regulator that governs the charging rate from the alternator. If the lite is burned out the charging circuit is non functional. One side of the lite is system voltage, the other side is alternator voltage. When the two systems are close to equal the lite goes out. So in your system, right now the two are not close together. I would check a couple of things, first all the battery connection cables, both ends, for corrosion and tightness. Next the ground strap on the alternator and mounting bracket and the ground strap to the engine. Then the four studs in the center of the fuse panel. About 90% of Opel electrical problems are ground related, loose or dirty connections and corrosion. HTH.

[tekenaar]

Originally Posted by namba209 Here's a quick primer on the charging circuit. The light in the ammeter sends a signal voltage to the regulator that governs the charging rate from the alternator. If the lite is burned out the charging circuit is non functional. One side of the lite is system voltage, the other side is alternator voltage. When the two systems are close to equal the lite goes out. So in your system, right now the two are not close together. I would check a couple of things, first all the battery connection cables, both ends, for corrosion and tightness. Next the ground strap on the alternator and mounting bracket and the ground strap to the engine. Then the four studs in the center of the fuse panel. About 90% of Opel electrical problems are ground related, loose or dirty connections and corrosion. HTH.

This is for GTs . . . his is a Kadett.

[namba209]

Ooops, I shoulda remembered from the fan blade posts. Sorry.

[baz]

i always find the avatar a help ron

must have been an old people's moment

[namba209]

Originally Posted by baz i always find the avatar a help ron must have been an old people's moment

Yeah probably, that and it was dark thirty.

[Ray Morley]

I checked every inch of wiring and I see no issues with that part of the problem.

When I start the car the ammeter reads 0 (centered) but when I load up the electrical system by turning on the park lights, head lights etc it now shows a negative indication. Is this normal???

I thought the ammeter would initially show a negative value and then the Voltage Regulator would then compensate the load and the ammeter would show a 0 or a plus value.

Is this true?

[namba209]

Originally Posted by Ray Morley When I start the car the ammeter reads 0 (centered) but when I load up the electrical system by turning on the park lights, head lights etc it now shows a negative indication. Is this normal??? I thought the ammeter would initially show a negative value and then the Voltage Regulator would then compensate the load and the ammeter would show a 0 or a plus value. Is this true?

That's the way it's supposed to work. You may want to check the voltage regulator plug in the back of the alternator beings that was the last area you worked on the car. Or the check of battery voltage suggested previously, but you'll need a VOM to do that. Check the battery voltage with the egine off, then again with the egine running at fast idle. There should be a very noticeable difference between the two readings. 12.5 V engine off and 13.8 V- 14.2 V with the engine running. HTH.

[tekenaar]

Originally Posted by Ray Morley I just replaced the fan belt and its at the proper tightness. When you key the ignition to the 'on' position the alternator light is full bright red as normal. After you start the car the light continues to glow red but very faint. Revving up the engine has no change to the intensity of the light. My Kadett Rallye also has a separate alternator guage and its not showing any problems at all. If I turn on all of the electrics the guage shows a slight negative indication then returns to the center. Any ideas? This is a new problem since I replaces the fan and belt yesterday. Could I now have a voltage regulator issue?

Uh Ray, there seems to be some confusion here . . . the "alternator light" is NOT red, it's amber and is the left, bottom one. The right, bottom red light is the OP light . . . so check your OP sender connections!

[Ray Morley]

OTTO........you are right! Good catch on that one..........I am totally impressed

I rechecked all of the wires again and found a problem with a fuseable link near the volatge regulator coming off of a seperate termainal block. I repaired that issue and now the red light is now off (not dim when engine running) and the voltmeter is showing the correct indications.

[Ray Morley]

Hey OTTO........I just checked my Kadett handbook.

1970 Kadett on Page 10

Charging Indicator Light

Light shows RED when Ignition switched on......located lower right bottom of circular guage.


Oil Pressure Light

Indicator light shows ORANGE when Ignition switch is on........located lower left bottom of circular guage.

[Ray Morley]

Otto......take a look at the black covered 1970 Kadett and GT Service Manual.

Go to Section D page 120-17

The photo on this page shows the Charging light on the left and the Oil Pressure light on the right.

Now turn the Page to 120-19 and refer to the photo in the top left corner.

They have the lights reversed in this photo.

This photo is what the Kadett handbook shows.

Ray

[tekenaar]

Ray,
Check back of the FSM, Section D - Kadett Instrument Panel, Figure 120-13 Arrangements of instruments, clearly shows OP indicator, lower right and red; charging indicator, lower left and amber . . . identical in '68-'72 manuals . . . but, went out and physically disconnected OP sender connection, turned key on and no AMBER light . . . hmmmmm!

Well at least all the FSMs show the same error . . . just another one of those "dear-to-our-hearts" little Opel anomalies!

[Ray Morley]

I would say that 120-13 picture data is incorrect.

I checked the owners handbooks for the years 67-68-69-70 and they all have the Oil Pressure as Yellow on the bottom left and the Gen Light as Red on the bottom right.

This also is reflected by pic 120-17 and also 120-18 and the wiring diagram on Page 120-28.