Jeep Pioneer

1990 Jeep Pioneer Drive Train / Driveline   

The part-time 4WD indicator light does not illuminate when I place the mode selector lever into 4-high, or 4-low. How do i determine if these settings are working correctly?

Check the vacuum servo (on the right hand side of the front axle,just inboard of the wheel)by looking at it,Or use a vacuum pump.The electrical switch for the lamp is also there,test it while you're down there.If both check out okay,then you probably have no vacuum coming from the vac switch on the transfer case.The servo needs to slide a splined coupling about 1 inch outboard to engage the front wheels.

I was looking more for how to physicaly tell if the 4WD High mode is engaging. Will the front axil be turning? The previous relpy tells me where to check if it is not. I'm not quite there yet.
Thanks

OK...sorry about the misunderstanding.All you need to do is put the front end up on stands.start the motor(you need to have vac for it to work).Leave the truck in neutral,but put the transfer case in 4h.You should then be able to rotate one front wheel,and see the other one rotate in the other direction through the differential.THEN have someone hold one of the front wheels steady,and the opposite wheel should not turn,as it is coupled with the 2 rears on the ground.if either front wheel spins freely,your 4wd is not engaging.

1988 Jeep Pioneer Ignition System   

when i tried to start my jeep it just turns over ,normally she runs great with no issues but now you just crank and crank with no start. i have tried a new coil the plug wires and coil wire are new (just a few months old) i have tried to change fuel filter also.next i will try fuel pump i guess but i am out of options any ideas?????any will be appreciated

Before you randomly change any more parts, try to determine if it is soark or fuel related problem.
Have a friend hold a spark wire with a plug attached against a metal part of engine while you are cranking it over. A pair of insulated pliers and dry gloves are an asset, unless you friend is planing an afro type haircut! If no spark then we can assume it is getting fuel.
With gas cap off have an assistant listen for fuel pump 'hum' when key turned on.
No hum means pump not working.

thanks bruce this will help since i do all my own work

If you want to, let me know how things go. I will be back on this evening (west coast time)

excellent im on the west coast southern cal.thanks again.

1987 Jeep Pioneer Electrical / Lighting Systems Dimming When idling When warm 

I have 2 questions:
1. Is there any way to retrieve engine codes without a reader. I have not seen an OBD2 port under my dash, but I have seen the two diagnostic ports under the hood near the relay bank. Is there someway to jumper a couple spots and get that light flashing? Also, my check engine light never comes on, should it? Even when I first turn the key?

2. I have a newer alternator (1 yr old) from NAPA, I beleive it to be 105 AMPS, but my headlights keep dimming when I am idling and warm. When I first start up the meter reads 12 Volts, when I am warm it will drop down to about 10 maybe less I can't tell. I am thinking that perhaps something else is drawing power, like maybe my ignition coil cuz it looks original. Waht do you think?"
Electrical / Lighting Systems - Dimming - when warm - when idling

Hi
That is the diagnostic connectors under the hood, but codes cannot be retrieved without a scanner. The Jeeps of those years had no check engine light. Quite amazing. I suspect your alternator is failing and causing the low voltage. If it has a bad diode, or winding, it will tend to show up at idle without ever turning the warning light on. You can likely remove it and have it tested for little or nothing.
Best wishes
Sterlingfixer

So how do you tell if your ignition coil is dying?

Good question!
Usually a failing coil is first noticed by the lack of spark, or weak spark. (Unfortunately, this is often after a tow.) To check the coil while it is still working, with the engine running, the coil should feel warm, but not hot. I use an ST-125 spark tester on the coil wire. It should make a vibrant spark across the gap. Current ramping is another way to test it, this requires an amp probe and graphing multimeter or oscilliscope. The current should build evenly, then peak and drop suddenly with each firing. OR, replace it to be sure, $67 from the dealer.

If my alterantor is at fault, and I replace it with an aftermarket one, how do I know that it is powerful enough? Can I get an alternator that will overload my charging circiut? What would be too much? 160 AMP?

Usually there are only 1 to 3 options from the factory regarding the output of your alternator. If you order alternator for your vehicle, it will be the right strength. An alternator specialty shop can built the alternator to be extra strong, then they will need to put a thicker wire from the alternator to the battery. If you buy from NAPA, it will be the right output.

The 6-cyl came with a 61 Amp or a 100 Amp alternator. The 100 Amp had a 6-groove pulley and air conditioning.

I do not recommend anything over 110 Amps, or you will burn up your wiring. Your problem is not coming from an alternator that is too small. You are not getting enough output at idle, meaning either the pulley is too large, or more likely, the alternator is partially failed.