All Warning Lights Are On

[orange9mm]

Got in my car today and started it up and every one of my warning lights ( central computer as well as the light is dash ) are on. All except 1, the battery light. Could this be the culprit? I have read somewhere that this light effects the charging system in some way. Could it cause all my warning lights to go off? I have a '78.

[Danglerb]

Does the battery (charge) warning light never come on?

Is the alternator charging ok, battery charged ok?

[Alan in AZ]

It probably means your alternator is dead.

Likely you are running on battery alone - if your volmeter reads about 11-12v when running you have an alternator problem... it could also just be a connection issue on the dashboard exciter circuit that feeds the alternator and tells it to turn on.

Alan

[orange9mm]

The battery charge light does come on in the 1st key position just before starting. It has only come on a few times, just after starting, in the past 6 months, a simple rev would fix it. It has never come on while driving the car though.

I will measure the current at the battery tonight. It was dinner time and I was a little frustrate at the car at that moment.

Most of the time the Voltmeter reads under 12v. Occasionally I have seen it above 12v but that is not very often. I just assumed it was a flakey gauge.

What are other symtoms of a dead/dieing alternator on this car. Wouldn't I have a hard time cranking the car if I was on pure battery? Why would this cause every one of my warning lights to go off, what is the therory on why it happens.

I did disconnect the battery for 30 seconds to reset the central computer as suggested somewhere. It had no effect.

[BIMMERMIKE]

Sounds like the central warning computer located under your dead pedal. I had the same problem. All warning lights on while car running. Replaced unit and all is good.

[Alan in AZ]

All the dash lights staying on is usually simply a continuation of the bulb test. This normally starts with ignition on and is maintained until the alternator starts generating.

The test for generation is the altarnator driving the other side of the charging light on the dash up to 12V+.

If the charging bulb illuminates before you start the car and goes out when you have started the car - then that seems to be behaving correctly and the central warning unit is perhaps the culprit.

Check the system voltage when the car is running with a reliable voltmeter. if its less than 12.8v @ 2k RPM you have an alternator/wiring problem.

Whilst the central indicator module could be a fault - its more commonfor the alternator or wiring to it to be at fault.

It may be your alternator generates OK at high rpm and you are barely charging the battery sufficiently....?

Do you see >13.5v at 3k-4k RPM?

Do the dash light go out at this point?

A failed or failing alternator will eventually yield you a dead battery - since its not getting recharged - but until then it will start the car - just progressively weaker as time goes on...

Alan

[DanielDudley]

Check your belt tension as well.

[orange9mm]

good news

battery read 12.76 not running and 13.97 with the car running so my charging system checks out.

bad news

my warning lights were operating normally tonight, so i have no idea what happened and i am sure it will crop up again when i least expect it.

i did notice this time that during my usual step of letting the fuel pump run for a second in key position 1 nothing happened. i had to turn the key back in the off position and back to key position 1. this is leading me to suspect the ignition switch as i have noticed this before. sometimes i get nothing in position 1 and sometime i get nothing in the crank position. all i have to do is turn the key to off and then try again and all is well.