Disconnect alternator and start engine turn on headlights and see what is does.
Help. Electrical system/lights pulsing?
- Thread starter hot_rod_hooligans
- Start date
hot_rod_hooligans
Well Known Member
Did the same thing with the previous 2 alternators(thats what started me digging into the charging system in the first place), so I HOPE that the alternator wouldn't be the issue, but knowing my luck......
hot_rod_hooligans
Well Known Member
hot_rod_hooligans
Well Known Member
Could the chrome alternator and bracket be causing an issue? I’ve had a couple of guys now mention that they had issues in the past. Possibly a grounding issue?
hot_rod_hooligans
Well Known Member
Or is it that the alternator bracket is bolted to an aluminum head?
You are not showing 12 volts unless guage is off. Check direct battery voltage with battery disconnected to car wiring.
hot_rod_hooligans
Well Known Member
I'm at work right now, I'll check it tonight.
I've got battery to block, block to body, and body to engine, but yeah I'm going to build one for the alternator.
It can be 10 guage alt to engine block.
wristpin
Well Known Member
Basically your ground runs in series not parallel.
hot_rod_hooligans
Well Known Member
Lol I have a tendency to go bigger than I probably need, all of the battery/alternator/starter/gound cables are 2 guage, with the execpion of the power wire to the fuse block(and I didn't make that one). I am a firm believer in a robust electrical system.
hot_rod_hooligans
Well Known Member
I never heard it worded that way, but yeah. Though now that you mention it, I'm having a hard time wrapping my head around having a ground run in parallel.
I always prefered battery cables to starter and engine grounds to be larger.
hot_rod_hooligans
Well Known Member
Well, a bolt screwed into the back of the alternator and a 12 gauge ground wire to the fan shroud mounting bolts didn’t change much, if anything. I’m stumped. I guess I’ll revisit the power wire from the battery to the fuse box tomorrow
Read battery voltage with positive cable off. Then read voltage at battery with engine idling No fan on or anything else.
Take alternator off and have it checked somewhere. Oreillys here does it .Don't know if you have one.
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hot_rod_hooligans
Well Known Member
I have one right around the corner from my house that I used to work at. It’s nice because I can still go in and look up/pull my own parts.
hot_rod_hooligans
Well Known Member
Battery tested 12.6V- good needs charged. Tested the alternator on the vehicle, started about 12.3V no load, then it had me turn on the lights, dropped to 11.7-11.4V, showed bad regulator, been doing this from day one out of the box .
Should be around 14.3 running ,nothing on fans lights ect. Definetly not charging.
12.6 volts on the battery is right where it should be when charged and after any residual voltage has been drawn or load tested off. Are you able to bypass the voltage regulator to test just the alternator output? With the voltage pulsing, my guess is a regulator issue.