When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
All the lights on my 77 f150 ranger fly flicker while the engine runs. They flicker to the rpms of the engine. I have looked all over for bad grounds. I've searched the internet for solutions but to no avail. Any suggestions?
At higher rpms the lights don't get brighter, they just flicker faster to where you can almost hardly notice it unless you actually look
Then it is RPM sensitive...Clean and reattach the grounds. Maybe add a couple of extra grounds.
Also consider installing a headlight relay harness so the headlights source voltage directly from the battery instead of the headlight switch. It's $30 well spent. I'm gonna bet the old wiring just has alot of built up resistance (load) that is affecting the headlight current.
In general, flickering has lots of potential causes. Flickering in proportion to engine speed sounds like an alternator problem... bad diode or something like that. Pulling the alternator and getting a test would help nail it down. Test at an AP store may work, but better a dedicated auto-electric shop.
Ok so while I was driving the other night I was watching my voltmeter in my dash and it was bouncing all over the place and the more I watched it, I noticed that the lights actually flicker in time with the voltmeter needle bouncing, and when my radio is on, there is static that comes on and off to the same frequency as the lights and voltmeter.