All lights are pulsing?

TBOAT13

MEMBER
1998 DODGE STRATUS
2.4L
4 CYL
2WD
AUTOMATIC
130,000 MILES

I installed an external voltage regulator because PCM was not controlling voltage to battery. I noticed that, after I installed it, the dash lights and headlights were pulsing. I have checked the ground and tried different locations for sourcing power, but have not had any success correcting this issue. Any advice will be appreciated.

Tuesday, December 23rd, 2025 AT 12:01 PM

2 Replies

CARADIODOC

MECHANIC
34,367 POSTS

What kind of regulator did you use? Chrysler's 1970s unit is what is commonly used. Did you do any diagnostics on the system before modifying it?

Is the pulsing a regular surge up and down, an intermittent flicker, or something else? Measure the battery voltage with the engine running and tell me what you find. Is there anything you can do to cause the pulsing to occur, or to occur more often?

Was this

answer

helpful?

Yes

No

Tuesday, December 23rd, 2025 AT 12:52 PM

TBOAT13

MEMBER
10 POSTS

Original test found voltage in the 16 voltage range. Not seeing a voltage regulator under the hood, and not realizing that the voltage was regulated by PCM, I bought a new alternator. It came with specific instructions for testing, and that test showed alternator to be good. I installed the new one anyways. Since I was getting 16v I thought the regulator was the issue. Then I installed the external regulator. The pulse is constant and doesn't seem to change regardless of load. I have attached a couple of videos. Thanks.

Image & Videos (Click to make bigger)