dim lights

[stu's jeep's]

i replaced battery,alt,checked all wire's checked belt it is hard driving at night i also installed driving lights and they are a little more brite but still not enough also installed new head lights ,stock any idea's:gonnablow

[Gerr]

umm dont know where to begin but if you share a bit more info on your jeep it may help spark someones memory

[Matthew Currie]

Since you already replaced the headlights, I assume you also checked the connectors at the headlights themselves, for corrosion. It can eat the terminals right off a sealed beam, and doesn't do much good to the plugs either. Have you tested the voltage at the connectors?

Mostly for pre-97: Check the harness connector near the bulkhead on the driver's side, again for corrosion. It can raise resistance, and once again, at its worst, it can eat the pins right off the connectors and leave you with lights out.

Any year: Don't forget to check grounds.

Finally, check voltage at the battery when the lights are on, to make sure your alternator is really putting out what it should, and the belt is really tight enough, etc.

[stu's jeep's]

11.7 lights off 11.6 lights on 9.8 low beam 8.8 high beam checked all wires to lights checked ground wires i even added a ground wire from alt to chassie the only thing i think that would go is headlight switch it is orig:roll: thanks to all who help

[Gerr]

those numbers are low you dont have a good ground OR your alternator is not putting out

[stu's jeep's]

the numbers are with the radio on and the heater is on, alt is brand new i replaced 2 alt and 2 battery's within 1 year and still lights are dim and both alt are factory from jeep at $198.00 each and 2 new battery's at also $120 for both and still the same thing so all money spent is $320 for the same thing dim lights:dunno: :dunno: :dunno: :shiver: :shiver:

[Blaine B.]

Heater on won't matter, since that's just letting coolant flow into the heater core. Blower fan or AC would matter.

Still, low. Take it to autozone or whatever and have them test the alternator and battery.

[stu's jeep's]

that is where i went and had all checked ,,,the only thing i noticed is that when the 1st alt and battery went i noticed battery acid blown all on the side where the battery is not a lot but enough to noticed acid spots on frame and on oil filter:flame: :flame: :flame: :flame:

[Matthew Currie]

Those voltages are low indeed. Of course I suppose it's worthwhile suggesting that the first thing you should do is make sure your voltmeter is accurate. Let's assume it is.....

If you don't have an alternator or battery problem, I would expect you have a problem with your wiring, perhaps aggravated by the acid bath. It's possible a cable is eaten away internally without being conspicuous, or a resistive connection at the starter terminal, or a rusted connection at the engine ground. Time to go through the whole thing and find why there's so much voltage drop. Grounds? Main cables? Terminals? Something is not right.

[dizzymac]

Considering you have a good batt. and alt, I would be checking in to the wiring a little further.Follow the wires back from the headlights to the connector and check it for corrosion, that will raise havoc with the output of your headlights.
In your profile its states you have an 86' XJ, if thats so I would be upgrading the harness.

[stu's jeep's]

is it possible to have bad fuseable links??:confused: i did check mine and they are soft near starter solenoidparty1: party1: did check ground wires the one that goes to block is fine checked the wire blocks near battery all look great now i am :shiver: :shiver: :shiver:

[Matthew Currie]

I'm confused now. Where are you making your voltage measurements? At the lights or at the battery? If the voltage at the battery is going low, then the fusible links and switch aren't likely the problem, since increased resistance will reduce current draw and should not drop battery voltage. But if you're getting bad voltage at the lights while the battery voltage is correct, then definitely you should start tracing the voltage, and see for example if the voltage into the switch is the same as that out.

If the readings are at the battery, then the lights are pulling more current out of the battery than is going in. Look for either a bad alternator, bad terminals, or bad wiring. Don't overlook the possibility that some wire, such as the main charging wire from alternator to battery, is eaten away inside even if it looks good. Measure resistance if you can.

There's also a slight possibility of a short circuit or leakage in the wiring to the lights, but it's unlikely, especially if you did already check the wiring. Since your readings are varying very reliably with the status of the headlights, you could easily check that by simply unplugging the headlights. If the voltage drop improves greatly, then you can be pretty sure that the problem is current draw from the lights, not from the wires.

[stu's jeep's]

i installed aux lights and they are too dim i checked all gound wires i even removed and cleaned them for better contact checked belt tension, replaced headlights, checked fuse box for a bad fuse. I checked battery volts at battery

[stu's jeep's]

help i am lost:angel: i let truck for 20 min battery went stone dead no lights were on i put a charger on battery for 15 min and truck started right up :) and guess what bright lights:confused1 :confused1 and the battery is a 14.1 no lights on battery is at full charge:explosion :explosion

[stu's jeep's]

well it went dead it started out at 14.1-13.3-12.1-11.5-10.2 and turned car off and dead it would not restart ran on idle 15 min now i belive it is bad alt BUT i brought it to AUTO ZONE and they tested the alt and it was fine so i am just going to replace it,, well whats anouther $120 now i have $480 in alt and battery's ,,,2 battery's and 3 alt in less than 6 months this 3rd alt i will not buy from the dealer go after market:explosion i am ready to sell this piece of s - - t

[1985xjlaredo]

So what happened finally