How's the tension on the belt? Does it look like it's slipping?

 

I'll look but the belt is pretty new. Like I said in the other thread it only seems to do it when the ac does it's deal. to me that would be liek a power surge and making the lights go dim

 

You've probably got a flaky connection in the power or ground leads, maybe a bonding strap that's gone south. Time to do some troubleshooting before spending, I think.

 

Agreed. The factory alternators put out more than enough power to run all the truck's factory components plus a couple accessories without taxing it.

 

a couple? Have you looked a my truck? lol

 

If it's lack of power....why don't you go dual batteries?? I did this with mine because of electric plows (front and back), flashers,extra lights etc etc and never had a problem after that. All on the original Alt.

 

I could be so wrong on this that it's not even funny, however in my experiments, if the A/C runs just fine you don't have an amps issue. If you crank the AC full cold and the clutch will not run more than a few seconds at a time then you prob have an amp/voltage issue.

As soon as you exceed amp draw, the AC will cycle long enough for the computer to register the drop and gain. When my POS E-fan is on my AC will not run. As soon as it kicks on I register a .4 drop in voltage (or there abouts) and the ac kicks off. Couple of seconds later after the voltage has climbed back up the AC will kick on again and then off.

Once the E-Fan is disconnected from the circuit it will take a few AC clutch cycles to return to normal operation.

Assuming you have fused all your accessories, when you disconnect all the add-ons do you lights still "blink"? How about when the truck is NOT running. This should take your charging system out of the equation.

 

What????

Dude, a compressor clutch coil on any normal automobile only draws 3-6 amps, and that's through the relay. The relay control circuit from the PCM is a fraction of that.

As well, the compressor runs the same no matter where you have the temperature control set. Vent temp is regulated via the blend door. When the compressor clutch is on, it's on all the way, period.

A/C compressors cycle because the pressure needs to be regulated. Except for variable compressors, the clutch cycling on and off frequently means the system is working correctly.

Bottom line, if he determines that the combined load of factory electrical components and the accessories he runs constantly exceed 80% of the alternator's rated output, he needs a bigger unit. If it's things like a winch, that are going to have a high draw for a limited duration and relatively infrequently, then a dual battery set-up is the way to go.

 

Don't be a dumba$$! Your going to sit there and tell me that it's normal operation for the the AC clutch circuit to cycle 2secs on 2 secs off? I don't think so. The PCM monitors the threshold, I don't know if it's voltage or Amps. If you are at max or near max load for your system and the 2-3 amp draw causes that threshold to be crossed you are either going to draw a code or one of the circuits is going to be disabled.

Still doesn't change the fact that you can use the AC clutch circuit as a pretty good indicator to let you know electrical system is or close to being maxed out. It's unlikely the head light circuit is the one that engineers designed as non-critical..... Dude!

 

Nope, it's not. Short cycling is an indication of an under or overcharged system, or a restriction that is causing pressure to spike very quickly. It is not, however, an indicator of excessive electrical load.

Please, do show me some facts proving this theory of yours.

For one, the PCM only monitors total system voltage. It can't see amp draw. That's why there are fuses and circuit breakers.

The computer doesn't disable select circuits when the system draw is too high; you simply loose some current to all electrical components, and it drags the engine down, even makes the belt squeal trying to spin the alternator under such heavy load. If the heavy draw continues long enough, you smoke the alternator.

Are you suggesting that the PCM also controls exterior lighting? I really wanna know where you get this stuff. It's pretty evident at this point that you like to speculate, but really have very little understanding of automotive electrical and air conditioning systems.