Spl310 1500 - Ignition Light

datsun65 · Post by **datsun65** » Tue Dec 06, 2005 1:08 am

On the cluster gauge on a 1964 1500 there is a small red ignition light. The light turns on when the key is put in the accessory position and upon initial start-up. Once the car is running the light turns off...

However, if the idle stumbles (for example when the car is cold) the light will flicker on until the RPMs kick back up...

So the question is...When the light starts flickering (when the engine is on, but stumbling) is this a sign that the charging system isn't charging properly (because the RPMs are too low), or is this light completely non-related to the charging system?

Thanks

Post by **spl310** » Tue Dec 06, 2005 6:57 am

According to the owners handbook, that is the Ignition Warning Lamp. Here is what it says:

"When you turn the ignition switch, the light will come on. The light goes off when the engine has started and comes up to speed."

So your observation is correct.

datsun65 · Post by **datsun65** » Tue Dec 06, 2005 10:28 am

I just don't get what the purpose of this light is...why have such a silly light, unless it also acts as a dummy light for the charging system?

67 1/2 1600 · Post by **67 1/2 1600** » Tue Dec 06, 2005 2:02 pm

Its almost like a modern car dash. Al the lights turn on the dash when you put the key in the "ON" postition. When the car turns on all the lights go off. Or if you stall and the engine turns off all the lights come on.

datsunfreak · Post by **datsunfreak** » Tue Dec 06, 2005 7:33 pm

datsun65 wrote:why have such a silly light, unless it also acts as a dummy light for the charging system?

It does.

Post by **spl310** » Tue Dec 06, 2005 8:30 pm

Remember that if you have the ignition switch turned to ON, the points will stay energized. With the car not running, that is a quick way to burn out the points.

datsunfreak · Post by **datsunfreak** » Tue Dec 06, 2005 8:33 pm

Good point...

A friend kept going through points like crazy. Never figured it out until I saw him repeatedly listen to the radio with the key on...

datsun65 · Post by **datsun65** » Tue Dec 06, 2005 8:53 pm

I understand the reason for when the key is in the accessory position...

But, why does it turn on when the engine stubles (rpms go down to 500-850) when the car is cold. It just makes me think it has something to due with the charging system.

datsunfreak · Post by **datsunfreak** » Tue Dec 06, 2005 8:58 pm

datsun65 wrote:But, why does it turn on when the engine stubles (rpms go down to 500-850) when the car is cold. It just makes me think it has something to due with the charging system.

Most alts don't work below a certain rpm.

Any time it dips below that rpm, the light will come on. Nothing to worry about.

DELETED · Post by **DELETED** » Tue Dec 06, 2005 10:50 pm

DELETED

datsun65 · Post by **datsun65** » Tue Dec 06, 2005 11:39 pm

all...thanks for the comments.

Been having some charging issues..Not sure if it because of lack of use (charging the system) or if the system is actually having an alt/voltage reg issue.

The 'IGN' light seems to be working (only turns on when engine not turning the alt fast enough). Battery is good.

How do I test with a multimeter to ensure the system is charging at the proper voltage?

datsunfreak · Post by **datsunfreak** » Wed Dec 07, 2005 12:44 am

datsun65 wrote:How do I test with a multimeter to ensure the system is charging at the proper voltage?

If you can safely reach it with the car running, you need to put the + lead of the tester on the big post of the alt, - on the battery negative or sufficient ground. Should charge 13.5-14.5 volts if it's working well. You want to check it with everything on if possible (headlights, heater, etc.) as well. Sometimes it shows good until you introduce a load.

Yes, I know that's a vastly over-simplified explanation... just trying to make it easy.