lights dimming/radio turning off while accerlating

[grimley]

hi all, i have a 66 fury that i have just gotten on the road. for the first month or so i didnt drive it at night and had no radio so i didnt notice this problem until i installed a new head unit and then that night, went for a drive.

ill try to give as much info as i can.

basically, if i idle the car (or have car switched off) and turn my lights on, theyre fine. as soon as i accelerate (or hold rpm above idle), my headlights and interior lights begin to dim and flicker between dull and normal constantly.

even with my radio off, and any other electrical accessory off, my lights still act the same when rpm in increased (and maintained eg. at 3500rpm).

as i mentioned, even during the day my cd player will turn off, again with the same symptoms. i think a few times big bumps may even cause radio to turn off, but then again i do have rpm above idle when driving.

i replaced my voltage regulator about 16 months ago when i was trying to get my fuel/temp gauge to work. i have also tried replacing the alternator over the weekend but made no change.

i only have the one cable from negative terminal to my block, this attachment point was right next to the headers. so i relocated the grounding point on the block so the cable has less heat (thought it might help). i also tried attaching a cable from the block to chassis as well, but all these were unsuccessful.

im out of ideas, any help guys??

 

[sb61fury]

Have your alternator, voltage regulator and battery tested. You can have this done for free at an auto parts store

 

[mr. fix it]

or you are going faster than the speed of light....... it happens to me all the time

 

[65sporty]

I would retest your alt, regulator and battery as Steph said. Also run a ground from the regulator to the engine and alt to engine. Yes it should be grounded by being bolted up but just in case. I like to triangulate my grounds. Battery to Engine, Engine to Body, Body to Battery. If anything is grounded to the Frame, than Frame to Battery, Engine to Frame. That's where I would start.

 

[traintech55]

Do you still have the factory mechanical voltage regulator? Also your ground cables should be battery to engine, engine to body. If you have a digital volt meter, hook it up to the battery and drive the car and see what is going on.

 

[kirkrush]

I had a similar problem once on a 69 Fury III and found that the stud on the back of the ammeter gauge where the main positive wire attaches was loose. I had to disassemble the gauge and repair the stud so it would be tight again.

 

[BJS racing]

Are the lights pulsing when all this is going on? That is typically a result of a bad ground on the voltage regulator.

 

[grimley]

I would retest your alt, regulator and battery as Steph said. Also run a ground from the regulator to the engine and alt to engine. Yes it should be grounded by being bolted up but just in case. I like to triangulate my grounds. Battery to Engine, Engine to Body, Body to Battery. If anything is grounded to the Frame, than Frame to Battery, Engine to Frame. That's where I would start.

battery is a 2.5 years old, reg as mentioned is about 16 months old. ill test my battery and regulator tonight or tomorrow. typically what volt should i be expecting with a calcium battery?

Do you still have the factory mechanical voltage regulator?

i installed a new mechanical volt reg from rockauto previously (i believe its More Information for STANDARD MOTOR PRODUCTS VR101T). i did install a electronic 5v voltage regulator for my gas and temp dials as the old mechanical reg failed.

Are the lights pulsing when all this is going on? That is typically a result of a bad ground on the voltage regulator.

yep, thats my main issue. i can live with radio turning on and off, however pulsating lights just draws unwanted attention and im sure if the cops see it they will pull me over.

thanks for all the feedback guys, ill focus more on the regulator over the next few days and hopefully report back some good news.

thanks again!

 

[traintech55]

battery is a 2.5 years old, reg as mentioned is about 16 months old. ill test my battery and regulator tonight or tomorrow. typically what volt should i be expecting with a calcium battery?

i installed a new mechanical volt reg from rockauto previously (i believe its More Information for STANDARD MOTOR PRODUCTS VR101T). i did install a electronic 5v voltage regulator for my gas and temp dials as the old mechanical reg failed.


yep, thats my main issue. i can live with radio turning on and off, however pulsating lights just draws unwanted attention and im sure if the cops see it they will pull me over.

thanks for all the feedback guys, ill focus more on the regulator over the next few days and hopefully report back some good news.

thanks again!

The radio turning on and off is most likely the protection circuit in the radio protecting it from excessive voltage. They have electronic regulators that look just like the mechanical ones. I bet your regulator is sticking in the charge mode.

 

[grimley]

The radio turning on and off is most likely the protection circuit in the radio protecting it from excessive voltage. They have electronic regulators that look just like the mechanical ones. I bet your regulator is sticking in the charge mode.

one thing i did notice over the weekend is that when the radio turns off, the ammeter is full scale on C for a second or two, then returns to the middle.

its a factory ammeter

 

[65sporty]

I would ditch the mechanical regulator and convert it to a electronic one.

 

[grimley]

Success.

Faulty regulator was the culprit.

I measured resistance from the chassis to negative terminal and it was 0.2.

So I found the original regulator and put it back in and solved all the problems I was having.

Thanks again to all that took their time to reply!