light problems

[cntryb28]

Hey guys... got in my pickup tonight to come home... . head/interior lights were "pulsing"(dimer-brighter-dimer-brighter)... any ideas? Bad alternator? By the way... great site... keep up the good work

 

[BushWakr - RIP]

What was the outstide temperatures during this? Did you just start up and drive away of idle a while to warm up?



Any other symptoms you can relate to this??



Bob.

 

[cntryb28]

The outside air temp was about 70deg. It "pulsed " from start up all the way home(about a twenty min trip). No other symptoms, just he lights. Its a fast pulse... not like a pulse would be from heater grids cycling. Stock volt gauge is showing above 12 volts when running... ... . not checked with volt meter... i think ill try that tonight. Did it agin this evning on the way home.

 

[BushWakr - RIP]

Ok that would seem to rule out the heater grids...



Double check the battery connections, including at the starter.

Make sure the grounds are in good shape. You may want to have the battery "load tested" to make sure you don't have some bad cells in it.

After that, someone else who's up on electrics may want to jump in here... .

Good luck. .



Bob.

 

[CDegner]

Mine does the same thing, but only at idle. Once I increase the RPM's by just a little, it goes away. Never have found a cause or solution. Different batteries, alternator checked, voltage regulator changed, grounds checked, etc. ...



If you figure it out, be sure to let us know. I have given up. When I am behind someone at a stop light at night, they think I am flashing my high beams at them.



Carl

 

[CrewCab]

Carl,

Your alternator at idle is unable to supply the current needed for whatever accesories you are running. Turn up your idle a little bit.

Terry

 

[CDegner]

With an 1100 CCA commercial battery and only lights and a fan on, I would think there would be nothing for the alternator to keep up with. Wouldn't be the first time I was wrong though (and I seriously doubt it will be the last, either).



Carl

 

[CrewCab]

But the battery puts out a lower voltage than the alternator. With the regulator cycling, the lights appear to change brightness from battery to alternator level. Or that's what I think anyway. What can you expect at 2:30 am.

Terry

 

[dpuckett]

Originally posted by cntryb28

Hey guys... got in my pickup tonight to come home... . head/interior lights were "pulsing"(dimer-brighter-dimer-brighter)... any ideas? Bad alternator? By the way... great site... keep up the good work

Could be voltage regulator. Had it happen on my 93 last fall; Does the Volt guage jump in time with the lights? Volt regulator is in the computer, but it can be bypassed easily and a standard regulator put in. Mine was very erratic- go well for several miles, then jump all over the place for a few; then back to normal. Get your alternator checked. I've had 2 crap out right at 150K.



Good luck and get back to us when you figure it out.



Daniel

 

[RamAZ]

Regulator bypass??

I have a 92 and I'm wondering who has bypassed the controller voltage regulator and installed the external voltage regulator.



My voltage on the gauge seems to be a little erratic sometimes. I have checked output of alternator and all is well but I would like to have an external regulator and directions on hand just in case.



Nothing like being broke down in the middle of nowhere and nearest repair shop is 100 miles away.



Thanks in advance.



Jim

 

[tugboatphil]

Daniel,



How did you bypass the internal regulator?

 

[cntryb28]

Yes Daniel... . wondering how to bypass stock regulator?????