kc light issues?

[herritage11b]

I just installed a set of KC driving lights on my 84 cj. Problem is while driving if i turn them on the jeep will seem to sputter out like it ran out of gas and shuts off, but i can push in the clutch pump the gas three times and restart it before i come to a stop. then it will be fine for about a min some times long some times less. the jeep will start with no problem after it dies everytime. im thinking the lights are useing so much volts that the fuel pump cant keep up with the engine need and there for starving the engine for fuel and it sputters to a stop, and the couple of seconds while the engine is off gives the pump enough time to catch up. the jeep runs fine with lights off. Any thoughts?

 

[mylittlecj5]

I assume you have an electric fuel pump then? Is it wired correctly, wire size and all? Who installed it, you or the PO? It isn't stock AFAIK.
Put a digital voltmeter on the battery, whats it read? Start the engine and then turn on the lights. What does the meter read before the lights are on and after? Rev the engine up to about 2000 RPMs, what does the meter read now (lights off)? With lights on?
These readings will start to help us narrow down the problem.

 

[BusaDave9]

My guess is your alternator can't keep up to the electrical demands. Was mylittlecj5 correct in assuming you had an electric fuel pump?
Do you have a volt gauge? What's it say.
I bet you may need a high output alternator to keep up with the power the lights use.

 

[IOPort51]

like the little man said, what size wire goes to what?? You should have at least 14 Ga stranded going to both. Are you using power directly from the battery and controlling it with a relay or are you going through the fuse block, light switch or other existing circuit??

 

[herritage11b]

yes i have an electric fuel pump. it was installed before i owned the jeep. its mounted on the body just in front of the fuel tank. the KC lights were installed by me with the wireing kit it came with. it is wired as instructed to the fues panel under the dash. it is wired to a fues that is only on when the ignition swich is on with a seperate on off swich that came in the kit. i havent looked at the wire size for the fuel pump, but the wire for the lights were supplied for them. ill check my voltage and post results tomorrow.

 

[mylittlecj5]

Did the kit come with a relay pack, or is it wired directly to the lights from the fuse box? What fuse is it hooked up to? If it is direct, and happens to be that one fuse that feeds power to the ignition or fuel pump, then we have found your problem.
I recommend wiring the lights to a relay (they are really not hard to wire at all) to keep the power feed as short as possible. Post up if you need a wiring diagram to install a relay if you don't have one now.

I just wired all my headlights and off-road lights with relays yesterday as part of a total re-wire. they also have self-resetting circuit breakers for safety.

 

[herritage11b]

Yes KC lights have a relay. main power to relay is hooked to fuse panel in fuse hole marked cruise control. main ground is bolted to the fuse panel main bolt. switch is grounded to the underside of dash with self tap screw.

I checked my volts at the battery here are the read outs

engine off 12.40v
engine at idle 11.97v
engine at idle with KC lights on 11.74v
engine at 2000 RPMs 11.98v
engine at 2000 RPMs W/ KC lights on 11.74v
engine at idle with headlights, heater fan, engine fan, radio, & KC lights 11.48v

 

[BusaDave9]

Bad alternator
You should have 14 volts when the engine is running.

When you are at the parts store I would also pick up a voltmeter for your jeep. It will help you monitor your electrical system before you have a real problem.
The battery should have 12 volts. When the engine is running the alternator should put out 14 volts.

 

[Cheepjeep85]

Bad alternator
You should have 14 volts when the engine is running.

When you are at the parts store I would also pick up a voltmeter for your jeep. It will help you monitor your electrical system before you have a real problem.
The battery should have 12 volts. When the engine is running the alternator should put out 14 volts.

judge cheep seconds that.

 

[herritage11b]

yeah i noticed that also. wish full thinking was hopeing this older atl only pushed 12 volts. i know most push 14v. i do have 2 volt meter in the jeep ones not hooked up and the other (original) never moves above 11 volts. i just figured it wasent hooked up correctly as nothing else has been so far. ive been rewireing everything correctly as there have been years of poor mods done in the electrical department. as it has a 302 engine i guess ill pull the atl and take it the autoparts store and let them try and find a match. mabye even a high output one.

 

[fzsk4p]

Look to see if you have an electrical rebuild/Alternator rebuild shop first. The OEM alternator can likely be freshened up with brushes and bearings for less then a rebuilt POS that most auto stores carry.

Example
2002 Chevy Silverado. Low/no charging

Bad diode was the fault. Added new brushes since we were in there. Total cost 35.00

New POS chump rebuild 200.00.

 

[BusaDave9]

I am also worried about supplying those lights with enough power. They really draw a lot. You might want to look into a high power alternator.

 

[fzsk4p]

I am also worried about supplying those lights with enough power. They really draw a lot. You might want to look into a high power alternator.

Convert the wattage of the lights into amps with the equation below..

amps = watts divided by volts.

14.0 volts is the standard used for automotive applications.

Add everything up and see what your total draw is.

Compare that to the alternator output.

Say 55w per light x 2 lights = 110 watts.

110 watts / 14 volts = 7.8 amps. Round it off to 8 amps.

So a pair of driving lights rated at 55w would draw about 8 amps.

What is the amperage of the average CJ alternator ? I don`t know but would guess around 75-80 amps ??

Unless you have some big butt stereo and a hoodfull of high power lights running all the time. The factory alternator would likely keep up.

Keep in mind that even OEM manufactures design the electrical system for only short term high draw. When in a high draw they relie on the battery.

Example would be a heated rear window. That heated window would only run for a short time. If the electrical system was overloaded by that heated window. Then battery would be responsible for the making up the difference.

Same logic as adding a winch.

 

[herritage11b]

These are the lights i installed

KC HiLiTES 634 Daylighter -6 In Black 130w Driving Beam Off Road Light System (Pair)

 

[BusaDave9]

These are the lights i installed

KC HiLiTES 634 Daylighter -6 In Black 130w Driving Beam Off Road Light System (Pair)

That works out to 20 amps. That extra accessory is far more draw than the OEM alternator was made for.
A car's alternator must be able to supply all the current for all the electrical components. A car should never rely on the battery when it's running. The battery is for starting the engine. Once it is running the alternator has to recharge the battery. When the battery is charged then the alternator is at 14 volts and supplying current for the electrical components. If you are driving home during a winter night with all the lights on, the wiper, the heater blowing and the rear defrost. The manufacturer must take all that into account. If the alternator can't supply the current for all those components then you are draining your battery. When you park your car you battery isn't fully charged.
You should never rely on the battery when the car is running.
Some people just like to have those big off road lights for looks. But if you intend to keep them on for any length of time I would get a high output alternator.

To install a winch you should use a 2nd battery for the winch. Otherwise stop your winch often to let the battery recharge. It is very possible to drain a battery when the engine is running. If you are winching away it is possible that you could get to the point that your engine would die. Then you wouldn't even be able to restart it.

 

[herritage11b]

I see amazon has some high output alternator for cheap. however they look like the pulley on them is set up for a serpentin belt as mine is runs on what apears to be a 3/8 belt. i can probly work around any bolt configuration but not sure how to fix the pulley issue.

 

[BusaDave9]

You could get a pulley puller
Amazon.com: Alltrade 648605 Kit 20 Power Steering and Alternator Pulley Removal and Installation Tool Set: Home Improvement
I would look a little further for one that just bolts up.

What engine do you have?
AMC 304
Ford 302

 

[herritage11b]

ford 302

 

[IOPort51]

call the local alternator shop and tell them what you have and ask what they can do for you. You may be surprised at the price being quite reasonable. They can do a high output modification and you have some one to go face to face with if you have any problems or questions.

 

[fzsk4p]

That works out to 20 amps. That extra accessory is far more draw than the OEM alternator was made for.
A car's alternator must be able to supply all the current for all the electrical components. A car should never rely on the battery when it's running. The battery is for starting the engine. Once it is running the alternator has to recharge the battery. When the battery is charged then the alternator is at 14 volts and supplying current for the electrical components. If you are driving home during a winter night with all the lights on, the wiper, the heater blowing and the rear defrost. The manufacturer must take all that into account. If the alternator can't supply the current for all those components then you are draining your battery. When you park your car you battery isn't fully charged.
You should never rely on the battery when the car is running.
Some people just like to have those big off road lights for looks. But if you intend to keep them on for any length of time I would get a high output alternator.

To install a winch you should use a 2nd battery for the winch. Otherwise stop your winch often to let the battery recharge. It is very possible to drain a battery when the engine is running. If you are winching away it is possible that you could get to the point that your engine would die. Then you wouldn't even be able to restart it.

Yes 20 amps would be a BIG draw. And I fully agree that combined with the other electrical loads. The stock CJ alt. would be undersized in this application. If it was an 8 amp as my example showed. Then I would disagree.

Also agree with your logic that the OEM alternator SHOULD be able to handle all the load(s) placed on it at one time. Unfortunately such is not always the case. I used the heated rear window as an example. An agruement could be made that adding the load of the power windows, power mirrors and other minimally used loads all at the same time can over draw a stock alternator. It is a reality on some OEM applications.

Is it right, no. Should they put higher amperage alternators in there, perhaps. With cost, weight, fuel mileage considerations. The OEM`s place a bet that it will work. Most times it does.

The second battery for the winch is a good idea also. Now the decision of hooking it up in parallel vs. an isolator comes into play. That is a debate that can go on forever.