Pulsing lights... what's wrong???

[GreenReaper93]

Hey everyone! I just bought this Cherokee last week. I didn't notice this untill the first night I drove it. What happens is that when I'm at idle the dash lights, headlights, and every other light pulses light to dim, light to dim....etc. etc. etc. While driving it's not so much noticable. What's the deal??? I thought it might be the alternator/voltage regulator, but the ECM (brain) controls the voltage. Can anyone please diagnose this so I don't go spending major bucks on something really simple? Thanks!!!!

 

[XJNick]

Hi,

Sounds like the alternator or voltage regulator is bad. Most of the time the voltage regulator is built into the alternator. The ECU regulates the voltage to the powertrain control system(s), but I think that's it. I've never heard of the ECU regulating the voltage for the entire 12 volt system.

Automotive alternators produce power output relative to RPMs at the motor shaft. So a weak or defective alternator could still appear to work properly at higher RPMs (when it is producing more current), but be producing far less current than it is supposed to overall due to internal problems. When I say alternator I'm also including the voltage regulator, which is usually integral.

-Nick :!:

 

[GreenReaper93]

RE: Re: RE: Re: Hey Greenreaper!!!!

Thanks Nick! I was hoping you'd be posting... I figured after the sweet Cherokee EV conversion you did, you'd definately could diagnose this. Ok, I'll get a new one this morning. Thanks again!!!

 

[GreenReaper93]

Ok, here's an update. I had the alternator rebuilt by the local alternator and starter shop and that took away the pulsing.....but I still have a problem. Whenever I rev the motor all the lights get brighter. Also, when I'm at idle the voltmeter drops. So now what? Any clues? Thanks guys!

 

[Saurian]

What all do you have running when this happens? If I have my blower, defroster, radio, headlights, what have you, all on at the same time, the voltmeter and lights will drop when at idle, and come back up when I hit the gas... Especially when it is cold... That's a lot of load on the system... If it's only headlights on, and it's doing it, could be another problem, for which I have no suggestion...

 

[GreenReaper93]

I was running Headlights, blower fan, and the radio. It seemed ok then...but when I got home I just had the headlights and blower on low and you could see a difference in the headlights when I rev'ed the engin. It's getting kinda annoying :x

 

[Saurian]

Hmmm... No suggestions here with a new alt, what kind of shape is the battery in? Or maybe it is idling too low for whatever reason... That's all I've got.

 

[GreenReaper93]

Battery's new... Yeah, it's really annoying not being able to figure this out.

 

[White]

Re: RE: Wheel Fit ?

Turn down the Stereo, I had the same problem. But a 200 amp alternator and some capacitors solved it.

 

[GreenReaper93]

haha, I wish that were the case. Stock stereo, man...

 

[XJNick]

Hi,

I had the alternator rebuilt by the local alternator and starter shop and that took away the pulsing.....but I still have a problem. Whenever I rev the motor all the lights get brighter. Also, when I'm at idle the voltmeter drops.

Three possibilities: Bad Alternator, Bad Battery, or too much electrical load for your current battery/alternator setup. I think we can safely rule out the latter as from your description you did not have too much turned on. We might also be able to rule out #2, as you said the battery is new. I say *might* because your new battery could be toast due to your old alternator not charging correctly. You'd be surprised how quick you can destroy a new car battery if the alternator isn't working properly. (The exception here being TRUE deep cycles such as Optima Yellow tops or Exide Orbitals, which are harder to kill :wink: )

Check the voltage of the battery with nothing turned on, and after the Jeep's been off for a few hours. What is it? Also, measure the battery voltage with the engine off and a single load turned on (such as the headlights). If the battery voltage drops a lot under load, it is likely been damaged.

However, it sounds to me like your alternator still isn't working right...

-Nick :!:

 

[XJNick]

Hi,

Turn down the Stereo, I had the same problem. But a 200 amp alternator and some capacitors solved it.

The problem is that many car audio amplifiers are so inefficient, and thus pull more power than necessary from the 12 volt system. Also, the public has caught on well to buying amplifiers based on how much power they consume, instead of how much they amplify sound.

What I mean is that most people buy based on the Wattage rating of the amp, thinking that the higher the wattage rating, the louder the sound an amp will produce. This is not always the case, as Wattage is not a unit for measuring sound output, but is for measuring electrical power consumption. Decibels are the proper unit for measuring sound. So, it is very possible that a 400-watt amplifer could produce less sound than a 200-watt amplifier. It all depends how efficient they are. So why then are amplifiers so commonly marketed by their wattage and purchased based on their wattage?? :?

I'll now end this digression
-Nick :!:

 

[White]

Running Class D and Class X . Not A Class A/B BBQ GRILL

Always looking foward to your post NICK!
Bout time you unvailed your EV, Remember when I stumbled onto your site. I though This guy is NUTZ.
At least now everyone Know's and not just me... ..That your crazy that is ,Nice Job.

 

[GreenReaper93]

RE: I have a problem

Hey XJNick, hey White! I tore apart the plastic shielding from some of the wire harness looking for the elusive (my spelling's gonna suck this morning) dark green wire with the red stripe from the wire diagram and guess what I found.... some dilweed has rigged the ignition coil to the battery instead of from the alternator. I tried to put things back to stock, but it looks like there might be a short somewhere in the stock wiring. My question is this... can I temporarily splice a 30A inline fuse and switch from the alternator wire harness plugin to the coil without melting something? Thanks so much guys!

 

[XJNick]

motorcraft carb help

Hi,

Running Class D and Class X . Not A Class A/B BBQ GRILL

LOL. That's good to hear.

Always looking foward to your post NICK! Bout time you unvailed your EV, Remember when I stumbled onto your site.

Yes I do. Though, at the time I'm not sure anyone else picked up on it. I've been driving the Cherokee as an EV for awhile now. But I wanted to wait until the right time to present it to my fellow Jeepers. Ironically, my Cherokee has been talked about or mentioned on many of the other major Jeep message boards (Pirate 4x4, jeepsunlimited, Naxja, and others, including some non-english ones) at some point or another during the project by people who found my website through the search engines.

I though This guy is NUTZ. At least now everyone Know's and not just me... ..That your crazy that is ,Nice Job.

LOL. Gee Thanks. Anyways, calling me nutz is way better than some of the opinions I saw on some of the other Jeep boards that talked about my Cherokee. Some people get surprisingly defensive the second you say the words NO GAS together. But I honestly don't give a damn what some people think about my project.

P.S. I'm very happy to see how supportive you guys here were/are about my Jeep EV :mrgreen:

-Nick :!:

 

[XJNick]

Hi,

can I temporarily splice a 30A inline fuse and switch from the alternator wire harness plugin to the coil without melting something? Thanks so much guys!

It is likely that you can safely do this. Do you know how much current your coil pulls? I'm guessing it is less than 30 amps. If you can find out for sure, and if it is a lot less than 30A, use a smaller fuse which matches it better. Be sure that if it truly needs 30 amps you use a relay, as most cheapo automotive switches melt at 30 amps. :mrgreen:

-Nick :!:

 

[Saurian]

Hi,


LOL. Gee Thanks. Anyways, calling me nutz is way better than some of the opinions I saw on some of the other Jeep boards that talked about my Cherokee. Some people get surprisingly defensive the second you say the words NO GAS together. But I honestly don't give a damn what some people think about my project.

P.S. I'm very happy to see how supportive you guys here were/are about my Jeep EV :mrgreen:

-Nick :!:

Not to digress from point of thread, forgive me, been up waaaayyy to long, and have to be at work in 5 hours, too lazy to start a new one...

I think it's an amazing project, something a lot of people don't think about is the fact that gas is not going to be around forever... If I have my Jeep years down the line when gas ends up being $10.00/gallon because it's starting to be in short supply, chances are, I won't be able to afford that... By then, I'd probably do the same thing that Nick did... The limitations on the technology are my only sticking point (besides the hefty price tag); performance and range are an issue, considering that I go long ways, odd places, and I like to do it fast... Having to stop halfway up north for 3 hours to recharge would make me a little tense... But as time goes on, I am sure that this will not be an issue... Whether you are for or against, it's an amazing project... I did my buddy's water pump, my heart stopped when he started it. When I drilled holes in the bumper to mount my frog lights, I almost had a stroke. And here's Nick, whom if memory recalls correctly is just out of high school, totally gutting his Jeep and recreating it to something not only completely different, but something it was never meant to be in the first place from the comfort of his own garage... Hardcore internal combustion or not, that's a heck of a feat...

Green, sorry I have no helpful hints regarding your lights, methinks Nick would be the one to listen to... Hope to see you running well by the time I get back downstate.

 

[XJNick]

Thank you, Saurian!

Incase you (or anyone who doesn't read the General Chat forum) missed it, I did start a thread about my Jeep EV conversion a little while back. I think it is now on the second page of that forum. Ok, here is the link:

http://www.jeepz.com/index.php?name=PNphpBB2&file=viewtopic&t=325150

Let's continue any furthur discussion about it in that thread (or we can do a new thread here), just so we can keep GreenReaper93's thread here relevant to his problem :mrgreen:

GreenReaper93, how's it going? Is your electrical system still acting up?

-Nick :!:

 

[graewulf]

grille guard questions

check the electrical connections at the alternator, battery, chasis, starter - make sure they are all clean & tight and have good contact. You could be dropping voltage at a bad connection.

 

[GreenReaper93]

Thanks alot guys for all the great ideas and responses! Here's an update from when I talked to you last.... I couldn't get a reading from the connector at the alternator. I checked the connector pin that runs from the alternator to the ignition coil and I received no signal. This now leads me to believe the connector block at the back of the alternator has become defective in some way. That's my only lead at the moment. I've checked every ground connection from what was mentioned earlier from graewulf. I'm going to take the alternator beck down to the shop it was rebuilt from. I'm starting to run out of ideas...