my 1993 silverado is having a problem, when it has been drivin for a while it starts to lose voltage, then comes back to 14 volts, then it loses voltage again, and then it cuts off and back on and pulsates or sometimes shuts off and if the turn signal is on it will pulsate along with the turn signal at times. I've replaced the battery, alt, ignition control module. I need to fix this quick.



Please y'all, this is urgent, i need that truck to work and i've been losing money since my birthday last week.


Thank you.

 

Have you checked the battery cables? given the age you might want to replace them as it sounds like you have a bad ground cable...

 

Given that You have installed a new battery and also a new/rebuilt alternator then it seems two of the ingredients has been eliminated which as stated heads a person into bad cbles or some corodded cables as has been stated by InPro.

 

I've put 2 new ground straps on the truck a few weeks ago. I think there is a third so might replace that one and the battery cables are 4 years old got those from the Chevy house.

 

I own a 93 GMC 1500 and the voltage meter on it does pulse when the flashers is turned on,I just thought it was the nature of the beast.
The voltage regulator built into the alternator should cut out when the battery reaches a voltage of,lets just say,about fourteen,or at least back off until the voltage drops to about thirteen five,then,it should kick in and recharge until the reading of about fourteen again,continueing this cycle constantly.
If the volt meter is pulsing I would connect a volt meter to the battery terminal on the back of the alternator and run the leads into the cab,drive the vehicle and when it starts pulsing then look at the volt meter and see what actually is going on.
If the voltmeter is also pulsing wildly then I would be for having that alternator checked out at the parts store where You purchased it at,it may be a defective unit.

 

my old 95 would do this and some days it would stay steady at 14V but then other days it wouldn't go above 10V. I just dealt with it since i was broke and couldn't buy the new cables that i needed. try running a second wire going to the battery from the alternator, my friend did that on his 97 tahoe and hasn't had a charging problem since

 

@MrMarty51 good idea, for the time being im gonna take my alt off and go test it real quick.

@chevyboy1993 hopefully i won't be having to do this.

 

it's not that hard, just took a 10 gauge wire and put an eyelet on each end and just bolted onto alternator and battery terminal. 5 minutes.

 

Oh just hard wire the alt to the battery?

 

YUP,I might give that a try Myself.