I have a 91 Subaru Loyale with push button 4-wheel drive.

 

From time to time, my 4WD comes on without me pushing the button. When it does so, my car drives very differently and pulls to the right.

While this is a problem, it is not the big worry. What ends up happening is that once this happens, I try to pull over and turn off the car. Normally, as I am trying to do this, my car makes a big thunking sound and it feels like I ran over a massive rock. Then the 4WD stops and it begins driving normal.

I'm just throwing my thought out here, but I'd try to disable the button, so that you can just enable it when you would like to use it. Idk if the mechanism is vacuum operated, or electric, but if it's electrical, then possibly you can pull a fuse to prevent it from engaging?

It's both. The button operates an electric circuit (actually, a pair--it controls which circuit of two are open/closed at any given time). The circuits, in turn, control a vacuum device that controls the 4wd 'lever'. The thunk most likely comes from the 4wd disengaging, unless it happens at other times in which case there is a lot of work and/or money coming up.

 

As to why it turns on randomly, I am uncertain. Perhaps a loose/floating wire that is grounding or shorting out one or the other circuit at (seemingly) random times; or bad solenoids. If you lift the skirt around the rear side of the shifter you will find the wires from the switch running into a coupler (it may be under the carpet, try pulling a bit). Check the colors of the wires coming out the other side of the coupler and see if you can figure out which wires these are at the vacuum control.

 

Do a search with the search function as to how to find the solenoids. They are in the engine bay and near the surface/easy to find. There are pictures of them in at least one thread. A multi-meter and eyeballing will take you a long way if the solenoids check out ok.

Check the wiring and check the vacume motor. Sounds like it is a loose or broken wire someplace. Grab a harness and shake the hell out of it and see what happens.

Is this an automatic or a 5spd, as the 4wd mechanism in each is entirely different.

Just a curiosity question; standard transmission vehicles were available with pushbutton 4wd?

Just a curiosity question; standard transmission vehicles were available with pushbutton 4wd?

 

yes they were, my 91 loyale has a manual trans with pushbutton 4wd

Good question Miles, I just assumed it was a standard. Oops! Guess we'll have to wait to find out.

this exact thing is happening to my car.

i have a standard transmission.

 

in addition to this problem, last night i was flagged down and informed that my tail lights were no longer working as well.

 

my heater core went out last winter and i had a friend bypass the heater core so that i would no longer have a floor covered with coolant. maybe something is loose in the dash that shorted out my tail lights and is messing with my 4WD?

 

i'm a n00b with car repair, but this car was gifted to me, so i am doing my best to learn a bit.

 

i'll check the wiring under the shifter and also check the wiring in the dash tomorrow. does anyone have a wiring guide pdf? also, i bought new tail lights today just in case the tail lights were simply blown (my headlights blew a day apart from each other last winter too), but i can't see how to replace them without removing the entire assembly. the blinker, reverse, and brake lights all have easy twist-to-remove-from-the-inside ports, but the running lights don't seem to have this. am i missing something?

Are you talking about running/tail lights in the back? (Not the brake lights).

 

Check whether you have a dual-filament bulb, that may solve your mystery. Iirc all the bulbs are accessible via the cargo hatch area in the car. Open the tailgate, remove the small panel covering the corner area. Tada.

yes, the running tail lights; the brakes work fine.

 

i know the hatch you are referring to and can access three of the lighting clusters. If dual-filament means that it can do both the running lights and the brakes in one bulb, therefore allowing the brakes to still work but the running look out, then i bet you are right.

 

i will try this out tomorrow! thanks!!

so i put in new bulbs and the running lights still don't work.

i have checked the fuse and it seems fine too.

 

is there a different fuse than the main one on the dash?

 

 

i've taken out my stereo and removed the dash underneath the steering wheel. it is a mess of wires. all look clean though and i am not seeing anything noticeable, but that doesn't mean that it isn't there.

 

anyone have any helpful tips or advice on how to solve the tail lights issue?

brakes work fine, the bulbs are replaced, and the main fuse is good too.

 

:/

the switch on the top of the column.

sometimes my tails go out and if I wiggle the column switch they come back.

I'll be replacing that soon.

Edited December 7, 201114 yr by zukiru
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