Hello all. The site really has changed over the years. Looks like a lot of work and a big improvement.
It’s been awhile since I’ve spent time reading most of the posts, but getting back into my project 78.

I was wondering if anyone could help me with a couple of electrical warning gremlins that I can’t seem to solve.
The first one...is the tail warning with the associated exclamation. This warning this only appears when the marker lights are turned on. My car is a 78 model and all three lights on both sides of the car work and look in good condition when removed to aft and one fwd.
I checked the amp output from the two associated fuses and the one side draws about 2.80amps and the other is at 3.20 ...does anyone know which is the correct one?
It would be nice to know which half of the car to tear apart.

The second problem I’m having is the exclamation warning (by itself) going off when the idle drops below about 1300...or when a electrical load is put on the system it requires a little higher rev to get it to extinguish...no other indications.
The alternator seems to be putting out voltage... have an increase once the car is started. To around 13.5 volts.
I’ve cleaned all the connections I could find....no help.

Any Ideas....Thanks in advance....if you can give me some new thoughts on what to do.

 

The lamp control unit really doesn't care which current draw is correct - it only wants to see the same draw on both sides. Possible causes include different bulbs on each side causing different current draw, or excessive resistance in one or more bulb sockets causing lower current draw.

The voltage warning may be because the alternator output drops off at low RPM. First thing to check is the most simple - make sure that the alternator belt is in good condition and is tight.

The excitation circuit sometimes causes problems, but that is normally only in getting the alternator started for the first time. Once the alternatoe has started putting out current, the output is normally enough to keep it going.

There should be another warning lamp lit - the little red mark at the end of the voltmeter scale should also be illuminated if the ! is on.

 

Thanks Wally for the quick reply. I will try the change all the bulbs with new trick to see if that helps, if not maybe I will have to add a resistor ..haha. I thought I could be smarter than the system at one point tying both fuses together to give them the same potential ,but that didn't work.

Thanks for the input on the alternator I will give the belt a couple turns to tighten it to see if it improves it.
The red indication on the volt meter must be out, because I get nothing. except the master warning light.
One thing I do notice and I don’t know if this is normal, but on initial start up the battery indicator is substantially brighter than the rest of the warnings. Is this normal?

Thanks

 

My 78 had two differently rated bulbs in the butt. This caused the light to come on and took 5 dollars and 5 minutes to fix.

And since we are on the topic, my oil pressure light warnings and ! flicker on while the car is cool- generally when I make an acceleration. My oil pressure reads at the 5 mark, and the red lamp at the low is ON. whats up with this? it's a relatively new occurance.