When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Stock Grand Cherokee Tech. All ZJ/WJ/WK Non-modified/stock questions go here!ZJ (93-98), WJ (99-04), WK (05+)
All ZJ/WJ/WK specific tech questions asked here!
Got this Jeep in on a trade, figured it would make a good project. 4.0/4wd. Interior is trashed, body is great (minus the front bumper).
This is first of any kind of Jeep, and after messing with it a little I found its going to need a good bit of work to be the way I want it. Its mostly electrical (which is not a strong area of mine, mechanically speaking). The power windows dont work, door locks, interior lights, and overhead console. Of course I checked all the fuses first, all good. Had a look under the dash by the pedals and was almost mortified by what I saw. Wires cut and hacked, connectors with wires cut out of them and spliced together, fuse links everywhere. I'm guessing this is more than likely where my problems lie. Awesome! Not. So.. I need to find a wiring diagram for all this stuff, but not really sure where to get one?? Its a 94 Grand Cherokee. Excited to get this project underway, not excited to do electrical!
Welcome to CF! If anyone can help you, we should be able to!
The major problem with most wiring diagrams I've seen is they are very cryptic and not really understandable unless you can follow the wire color codes. Sometimes the color code will change going thru a connector or disappear into a harness and you have to search blindly for where it comes out. For instance, my Chevy truck had a ground junction behind the dash that had 17 wires all grounding at one point! ARGH!
Your best bet might be to get a junk harness from another jeep for your under-dash setup. The body looks good, but check underneath for rust. As long as it's structurally sound you can fix everything else. Does it run? Is the wiring problems just for the accessories and windows or for lighting.
I'm hoping some other member will pick up on this post and help you as well. Welcome to the world of heartache called jeepin'!
Dave, thanks for the welcome! I'll be headed to the boneyard this weekend, gonna pick up some doors (my doors need new panels and window regulators, easier to just replace the doors). The frame is solid, no rust anywhere. It runs and drives, hell the air still works, 4wd works great as well. But yes, its just accessories that dont work, and the oil pressure gauge is always pegged (think it may be grounded) and the temp gauge wont get.over about.130 degrees.
Okay, as I said, welcome to jeepin'. The oil pressure sensor is a piezo-electric crystal and printed circuit device that requires good quality construction. Therefore, the only ones that you can rely on to work properly are made by Mopar. I bought a NAPA Premium one and all it did was read 30 psi EVER regardless of engine temp or rpm. $48 wasted. The Mopar unit was $67 but worked right. That is, of course, if it has more than 1 wire. Otherwise you're right, it's shot and shorted.
The thermostat has probably been removed. It's supposed to have a 210* stat in it for proper fuel trim requirements. Also, pressure test your radiator cap or replace it as necessary.
The 4.0 I6 is just about indestructible and long lived. The basic engine started with AMC in 1954 and has just about reached it's design limits for improvement. About the only improvements you can make that change anything are better injectors and the '99 and later intake manifold. It's a good, strong engine but it will never be a rocket.
If you're going for new doors, don't forget new hinge pins and bushings. You can get them from rockauto.com for $3.77 each.
Jeeps are a ball to drive. IDK when you're at, but I haven't found a better vehicle for snow.
Dave is right on when he says they are great on and off road my 04 WJ is my DD it has the Overland package so it is loaded with every option Jeep offered that year. It is the best year around all weather cars I have ever owned in my life.
I'm sure you will be pleased with your new Jeep and have fun!
New doors definitely seem like the easier way to go, better than piecing the guts for the existing doors back together.
The 4wd system definitely seems very capable. I hated my Durango's 4wd system, with cv axles up front there were too many weak points and I was constantly working on it.
I've heard a lot of good things about the 4.0 I6. Dependability is all I'm looking for. I'm happy with the power it already has, it's still a pretty stout motor, very torquey.
I'm sure I'm going to have a ton of questions, and I'll be posting pics of my progress. Sounds like it will definitely be a fun ride once I'm done.
Yes' the early (yours) 4.0 is a torque motor that develops it's max torque at 3000 rpm so there's not much point in winding it higher. The '99 and newer ones have a changed cam profile to produce max torque at 4000 and in my estimate they just don't feel as good at low speeds as the older models. My uncle used to call it the "tractor engine" lol.
The thing I like so much about the 4.0 is as long as you've got a good battery and the jeep has been maintained, it'll fire up in any weather conditions or temperatures. This past winter at -15*F, it cranked slow but caught right off. The battery was 4 years old and actually died this spring.
Got the new doors on today along with new hinge pins for both sides. Its nice to have door panels and armrests. Found the right colors to match as well.
I also installed an aftermarket head unit today (gotta have my tunes) and what happened after I powered it up just furthers my dread of the electrical system..
The stereo worked fine, no problems there, but I then noticed all of my interior lights are working (previously not working) and the power door locks are working as well, Windows are still not functioning. I'm not sure what is going on but I cant make sense of it. And they only work after the key is turned (switched power)
I drove it to the boneyard today to get the doors, and to look at the under-dash electrical in a hopefully unmolested vehicle, and was very surprised at the fuel mileage this truck got.
You hooked the dimmer circuit up to the aftermarket head unit, that is why the fuse blew for the lights. The windows will only work with the key in the run/on position.
Dimmer is not hooked up. No fuse blew. Power locks wont work unless key is in on position and radio hooked up. Courtesy lights only work when key is in on position.
Got my power window issue figured out. From what I gathered, the circuit for all the windows runs through the drivers side master switch. If this switch is bad (or in my case the drivers side door harness completely missing) none of the windows will work. Replaced the harness and replaced the 30 amp circuit breaker in the fuse panel (for good measure) and BAM! All of my power windows worked. Was especially relieved to know that all of my regulators worked.
05-27-2015, 11:26 PM
New Jeep, new project
