Pulsating Lights

Reply Subscribe

Thread Tools

Search this Thread

Jun 15, 2009 | 08:14 PM

429poweredf350

Thread Starter

Elder User

Joined: May 2009

Posts: 514

Likes: 3

From: Long Island

Pulsating Lights

My lights pulsate when the truck is running and the amp guage jumps as they do. Any ideas? Bad ground maybe????

Thanks,
Jerry

Jun 15, 2009 | 08:32 PM

Bullitt390

Certified Thread Hijacker

Joined: Aug 2001

Posts: 14,441

Likes: 59

Alternator or regulator.

Corroded cables can cause it too.

Is it pulsating at idle or going down the road as well?

Josh

Jun 15, 2009 | 09:06 PM

429poweredf350

Thread Starter

Elder User

Joined: May 2009

Posts: 514

Likes: 3

From: Long Island

Both at idle and going down the road. Cables are all new. truck just had a frame off resto.

Jun 15, 2009 | 09:08 PM

429poweredf350

Thread Starter

Elder User

Joined: May 2009

Posts: 514

Likes: 3

From: Long Island

Josh,

Alternator and regulator are new as well. I need to find a good wiring diagram. All the ones I've seen aren't all that good.

Jun 15, 2009 | 09:19 PM

Bullitt390

Certified Thread Hijacker

Joined: Aug 2001

Posts: 14,441

Likes: 59

Isn't too far fetched these days to have a brand new part not work correctly.

What year is your truck? I have a couple diagrams I could post or link to.

Josh

Jun 15, 2009 | 09:48 PM

429poweredf350

Thread Starter

Elder User

Joined: May 2009

Posts: 514

Likes: 3

From: Long Island

Body and wiring are a 77. Thanks for your help.

Jun 15, 2009 | 10:17 PM

murph77

Elder User

Joined: Sep 2008

Posts: 563

Likes: 0

From: DeKalb, Ill.

I think you're going to find a ground somewhere to be the issue.
Since you just had a frame off restoration, I would bet money a ground is the culprit.
Check ALL of them. Make sure they were all replaced, and the grounding
surfaces didn't get coated with paint.

I went through this last fall. Pulsating lights.
In fact, when I saw your post, I thought someone had resurrected my old one.
Mine was easy though. Bad battery ground.

Murph.