Red light, what does it mean?

[coffee break]

I have a red light on the dash that will come on when I first start the car and then go off after a minute or less. Any RPM over idle would make it go off. Recently, it has come on at lower RPM and go off at higher speeds.

What is the light telling me?

[locost7018]

On my locost it is the alternator light. On when just started and off after the rpm goes up. It came on solid when I lost a wire on the alternator. Russ

[NVP66S]

If it is the alternator light (which I do not know on your specific car), the operation is pretty simple, once explained. One side of the light is tied to the battery (+) and the other side to the regulator output. When the engine is not turning, the light is on because the regulator side is LOW and the battery side is HIGH. At some low RPM, the alternator puts out enough voltage to nearly match the battery HIGH, so the light goes out. If the alternator slowly fails, this voltage is reached at a higher engine speed, so the light stays on longer.

 

The other possibility is that it's the oil pressure light. Does your car have an oil pressure gauge?

Dan

Edited December 28, 2015 by NVP66S
more info

[coffee break]

The other possibility is that it's the oil pressure light. Does your car have an oil pressure gauge?

Dan

 

The car has a gauge and it is indicating good pressure. Thanks for the descripting of the alternator system.

[TheDingo8MyBaby]

According to the caterham manual:

 

Battery charging – RED

The light illuminates as a bulb check when the ignition

switch is turned to position ‘II’ and extinguishes as

soon as the engine is running. If it remains on, or

illuminates whilst driving, a fault with the battery

charging system is indicated. Seek qualified

assistance.

 

A few things to check:

-grounds/connections to the alternator

-belt tightness

-voltage regulator on your alternator

 

As long as the light is off most of the time, it may not be an issue, though it could mean you're due for an alternator soon.

 

-Geoff

[NVP66S]

According to the caterham manual:

 

 

A few things to check:

-grounds/connections to the alternator

-belt tightness

-voltage regulator on your alternator

 

As long as the light is off most of the time, it may not be an issue, though it could mean you're due for an alternator soon.

 

-Geoff[/quote

 

Yup. Or a voltage regulator. I recently replaced one of those in my wife's 300D. The brushes were worn down. It cost $36 instead of $180 for a rebuilt Bosch alternator (which includes the regulator). If it were the belt tension, you'd probably hear a screetch.

Dan

Edited December 28, 2015 by NVP66S

[coffee break]

I removed the alternator and took it to SHR Auto Electric (Sleepy Hollow Rebuilders). It was determined that the regulator was the problem. It turned out that the alternator is a relatively common item and they had a new unit on the shelf.

It's installed and no red light and 13.8v at idle.

[coffee break]

The Red Light is giving me a message but I'm not sure what is wrong.

Since I installed a new alternator the red light stays off at idle but, now it flickers at the same RPM as the engine stumble that has started. Between 4 and 5k the motor goes flat and I happen to look at the light and it was flickering. ???????

I'm thinking about putting a volt meter somewhere to look for voltage drop but it's a guess.

[scannon]

Check and clean all your grounding points. Make sure you have a ground cable to the chassis as well as directly to the engine.

[coffee break]

Check and clean all your grounding points. Make sure you have a ground cable to the chassis as well as directly to the engine.

 

Skip,

Crappy electrical connections were the problem. Voltage to the coil was dropping as RPM increased, 7v @4k and 3v @5k. My mechanic cleaned up the connections and it revs great.