1999 Jeep Wrangler - Page 8 - Answered Questions & Fixed issues

Have you checked the crank sensor? They are a common problem item on Jeep vehicles.

Did you replace the bloer motor also, usually a resistor failure is caused by a failing blower motor. here is a diagram to help with diagnosis, Make sure you have voltage at the blower motor connector with the key on. If not verify the fuses and the blower motor relay shown in the diagram. If voltage is present diagnose the ground side. The ground path goes from the motor, through the resistor, through the selector switch, then to the ground listed in the diagram.nosis.

blend door not opening or closing properly...vacuum control...may have to follow vacuum lines from heater control valve to doors and flappers

the fuel filter/fuel pressure regulator is mounted on top of the fuel tank between the fuel pump and the fuel supply tube, fuel going out

This light is problematic as I had to encounter this as well. For what it is worth, the job of removing it to replace a bulb, most likely an LED will not be worth the time. You know you are in 4wd when your steering becomes a bit stiffer and when you make a sharper turn feel your axles kind of bind or get stiff. The steering feels tighter or "heavier" and maybe your power steering labors more in a sharp turn. Once you drive with it on and off and pay attention to these aspects, you will know you are locked in 4wd. You should also feel a slight clunk or release when you are driving and you take it out of 4wd.

do you have a digital ododmeter on this model

Hello Tom,
This problem can be trouble shot by checking: The fuse. Are you 100% sure it is good? Get a new one unless you are sure. You said you replaced the resistor but still check it again to be sure it did not cook recently. It will appear crusty,melted carbon deposits. If you bought a good NEW heater motor check it again by getting or making some cheap jumper leads and by unplugging the heater connector under the hood, connect one of the leads to the battery then to one of the posts of the heater. Connect the other jumper to to the other post and to the connector on the motor. It should whirl around and scare the heck out of you it you get the polarity right : ) now, onto something more fun and where I think your problem is. Your control panel.... Using a phillips screwdriver, remove the screws from your face plate/facia/dash moulding covering your stereo/climate control panels. Screws located under eye glass basin,in back of cigarette ash bin and below I think. It pops off and exposes the screws to your climate control module. 4 screw/nuts allow you to pull out your climate module box. Check your connections. Most likely, your selector switch is melted. Perhaps even the harness that plugs into it is melted too. Replace the blower selector switch (small screw removes it) with a new one. Autozone carries them. If your wiring is toast, make a drawing of your color wires BEFORE you cut them free (what post on the switch the wire plugged onto by aligning the plug orientation to the post orientation "mated connections") and close to the connector as possible making sure the wire is good. Get some heavier gauge wiring and splice in and solder neat and strong extensions onto the cut wires. While you are at your auto store, pick up the appropriate female plug in connectors to fit over the blower speed selector pins. Solder these onto your extensions as well and liquid tape all bare wiring. Plug them onto the correct plug to the blower motor switch. YOUR VERY DETAILED DRAWING that you made. When I did this, I made my wire extensions about 8 inches long so I had plenty of room to solder and work. Check your connections,tape them to avoid shorts and use liquid tape on the blower speed connections if there is bare wire. Turn your vehicle on run through your selector speeds. You should also replace your RELAY. It is located on psngr side under glove box. Buy a good one. Replace this even if it appears to be working as they can get worn and as your motor gets worn, allow extra juice to backfeed and kill your heater components again. I hope this helps. If all of this fails your wiring harness may be cooked but I think this is your blower speed selector switch. I will be on here to check on you the next few days to see if you need any more help. Let me know how things turned out so I can help you more if needed. This is a very common problem with this model. Take care.

check blower risistoe on heater box,wiring also melts connector at resistor block

There is a heater control valve on the heater core hose. This is a common problem on the Jeep Wranglers. The valve is not opening.

There are two fuses a 40 amp in the power distribution center and a 10 amp in the fuse block. Are they good?

This is a ground side controlled system meaning the switch provides ground instead of power. With everthing plugged in there should be power on all the wires coming out of the blower motor resistor ( brown w/ tan, Light Blue, Light green w/ black, and tan wires). If you ground any of those wires the blower motor should run. If it does check the dark green wire at the HVAC control head. Backprobe that wire with it plugged in if there is power than either the control head is bad ( the mode switch has the final say in the path to ground for the blower motor. When the mode switch is in the off position the blower will not work. When it is in any other position (vent/floor/defrost) it allows the path to ground for the blower motor to be complete.

The last thing to check is to make sure the black wire coming out of the control head has a good ground. That is the final path to ground for the blower motor. I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

Check the cap rotor spark plug gap and spark plugs also check the timing get back to me and give me more details sounds smells vibrations

sounds like a loose belt, [and-or] weak battery. causeing belt to slip when altenator is trying to charg the battery.

If the battery just died for no reason, reason being the door was left open too long or a headlight,dashlights were left on or any application on your car was left on then your battery probably just needs to be recharged. If that not the case then it most likey your alternator if that dead then your battery was not being rechared/maintain by the alternator,even if you drove it that drive kill was power your battery had so in that case you will have to replace your alternator

Bad fuel, dirty fuel filter, dirty air filter, dirty injectors. I'm assuming there's no check engine light on. You should get upwards of 20mpg easy. try replacing the airfilter and fuel filter. I would get a K&N airfilter, i've had great luck with them. you should notice amore power and better fuel efficiency. Also, use an injector cleaning additive, like Lucas, and use synthetic engine oil. it cost more, but you'll change it less often and it's worth it. I'm a fan of valvoline. oh, and make sure your tires are inflated properly, that can make a noticeable difference

Had the same thing with my 2004 Wrangler. The Airbag light stayed on also. Took to dealer - Cost $400 for them to replace the ignition. Fixed every thing.

The temp reading on the dash is a very big clue... Likely the thermostat (at the end of the large top radiator hose inside the metal housing) is stuck open. When that happens, the coolant in the engine never reaches full temp. Not only can that result in a low heat condition but it can also give you poor fuel mileage as the computer always thinks the engine is cold and therefore it adds extra fuel to keep it running.
Replace with a 195 degree(f) thermostat, run the engine (with the heater on full heat) to nearly normal temp, turn it off and wait about three minutes, then re-start and continue filling. Once full, add whatever is necessary to the recovery bottle and close it up and check for leaks.

Look inside the engine compartment for a black box.
Inside will be a bank of small electronic relays.
Look for the one for headlights ,should cost you anywhere from $10.00 to 22.00
The same box contains air conditioner relay,charging relay,air bag,ect...

ucan not set the timing! it is controled by the computer as it monitors the crankshaft position sensor.

Have you checked your voltage at the switch to see if any is there?

http://www.jeepforum.com/forum/f11/no-bus-odometer-no-gauges-not-starting-524101/index2.html