Charging Issues?? Battery Light on

[BenDover]

I have an 87 Pathy SE 5 speed and recently my gauges except my speed would crap out and the battery light would come on. Usually this happens when i turn on my signals. My hazards work fine but my signal lights would turn my gauges off and my battery light comes on.

 

My cluster seems to be fine and accurate because when it works, it works great other than when the battery light comes on.

There were odd times where i would put it in reverse and back up for a bit and the cluster would work again and everything on my dash would light up bright.

I get 14.3-14.5 on idle at the battery with all loads (blower, defrost, and lights) and 12.4-12.7 when it is off

I have replaced the battery and alternator and the issue went away for a while then it came back after a few weeks. Idk has anyone had this same issue?

I am looking for advice on how to diagnose this.

 

[Frenchy]

I would verify the ground cable on the alternator is tight. Mine was loose on my 93 and was causing some odd issues with the instrument cluster 

[BenDover]

Grounds are tight!

 

[Frenchy]

Do this check with a DMM. First check battery voltage with vehicle running. While it's running leave the positive lead of the DMM at the battery and move the ground lead to different ground wires. That will help you find a bad ground. Start with that and go from there.

[BenDover]

i will try this thank you

 

[BenDover]

i have checked all my grounds in the engine bay and they are all reading the same 

not sure what else to do a this point.

[hawairish]

Sounds more like a short on the signal circuit, and the battery light illuminating is a false reading.  The charging function of the alternator should have nothing to do with the turn signals, of course.

 

I presume when you say the hazards work that the indicators on the cluster flash, as well as the front and rear exterior lamps.  It only doesn't work when you turn on the left or right signals?  And in that scenario when the gauge cluster cuts out, do the appropriate exterior lamps still flash?  If so, you should be able to trace it to either the flasher unit, turn signal switch, or bulbs on the cluster.  My hunch is at the cluster.  Maybe pull one bulb at a time and try the turn signal.

 

The reason the hazard function would work but not the signal is because they are two separate paths on the same circuit, but the hazard switch is near the start of that circuit.  The turn signal switch is downstream of that.