Lights "pulsing"

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Nov 13, 2011 | 09:37 AM

flbmcman

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Joined: Jan 2010

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Lights "pulsing"

Hi all,

Back again, hopefully with an easier problem than the last.

When the truck is running, it appears that the dash/headlights are "pulsing".

Can't figure this out, as the alt. is attached to the batteries, which should act as a filter.

any thoughts?

thanks in advance

Lawrence

Nov 13, 2011 | 10:03 AM

1994F2507.3L

Cargo Master

Joined: Mar 2010

Posts: 2,227

Likes: 149

From: Higginsville, MO

is this constantly happening or just for awhile after startup?

Nov 13, 2011 | 10:51 AM

flbmcman

Thread Starter

Freshman User

Joined: Jan 2010

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Quote:

Originally Posted by 1994F2507.3L

is this constantly happening or just for awhile after startup?

constant, not like the gp controller cycling

Nov 13, 2011 | 02:55 PM

vfelix702

Laughing Gas

Joined: Dec 2010

Posts: 1,155

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From: Las vegas nevada

try a voltage regulator its mounted on the passenger fender

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Nov 13, 2011 | 03:34 PM

Aune163rd

Logistics Pro

Joined: Sep 2010

Posts: 4,411

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From: Victor, MT

The big silver box is what he is talking about if you dont know...

Nov 13, 2011 | 05:56 PM

starmilt

Post Fiend

Joined: Oct 2007

Posts: 10,501

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From: Faibanks Ak.

Before buying any parts, unplug the voltage reg and jump the a and f terminal on the wiring harness to test the alt. If it is still serging you know for sure it is not the regulator.
I would then clean all connections, if the problem persists then pull the alt and have it tested.

Nov 13, 2011 | 08:01 PM

84-6.9L

Posting Guru

Joined: Feb 2011

Posts: 2,216

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From: Princeton MN

Check your whole alt harness, mine would do the same thing, I found the whole harness had burned wires and such. Take a look at it and check and recheck your grounds as well.