CO MJ Posted January 12, 2023 Share Posted January 12, 2023 Before I wire in cherokee power windows, I think I need to remedy a few wiring gremlins. I'm not sure if everything under my dash is supposed to be there at all or if it's in the right place. 1. In this photo there are 3 wires (ignore the yellow in foreground) that go into my fuse box in the rr wipe, ign, and gauge fuses. They run out through the grommet in the firewall to the engine bay. They look too new to be factory, any idea what they might be for? 2. I have circled what looks to be a blue cap over the end of a harness connector, what's this? 3. I have also circled a white relay, what's this? 4. In this pic is another view of the blue cap and white relay, as well as another blue relay and an inline fuse. What the heck? This is another view of underneath. Worth a note, either my pedals have been replaced or this truck used to be a manual as someone has hacked off the clutch pedal. 5. What's this box? Any idea why there's this random wire and inline fuse on the harness? 6. Anyone know what this box is above my headliner? Just two black wires that go down behind the glove box, can't figure out where they go to from there. No markings on the box. 7. What's this big plastic box in the middle? Link to comment Share on other sites More sharing options...
ghetdjc320 Posted January 13, 2023 Share Posted January 13, 2023 Lol, looks like someone took an axe to that clutch pedal. I Can tell you that those yellow and red wires in the front of the fuse box with spade terminals are not factory. Could be someone was searching for an ignition switched 12v source for some accessory. That number 5 item is the aw4 transmission ecu. Link to comment Share on other sites More sharing options...
pizzaman09 Posted January 13, 2023 Share Posted January 13, 2023 2. Blue box is the Sentry light box. This is the feature that keeps the headlights on for 45 seconds after you turn off the truck. Black plastic box is your floor heater vent. Link to comment Share on other sites More sharing options...
87MJTIM Posted January 13, 2023 Share Posted January 13, 2023 #3 the blue box is the seat belt/key/light buzzer. #4 the blue box is the horn relay. #5 is the transmission control unit (TCU) #7 is the heater vent Link to comment Share on other sites More sharing options...
jdog Posted January 13, 2023 Share Posted January 13, 2023 Suspect either an alarm or remote start for the black box above the headliner, Link to comment Share on other sites More sharing options...
eaglescout526 Posted January 13, 2023 Share Posted January 13, 2023 2 hours ago, 87MJTIM said: 4 the blue box is the horn relay Can’t be, the white one is the horn relay. Unless AMC did two of them for some reason. Link to comment Share on other sites More sharing options...
87MJTIM Posted January 13, 2023 Share Posted January 13, 2023 12 minutes ago, eaglescout526 said: Can’t be, the white one is the horn relay. Unless AMC did two of them for some reason. Ok. How about the radio/LED clock display relay C354? The location and wire colors appear to match. p. 59 of the 88 electrical manual. Link to comment Share on other sites More sharing options...
Ωhm Posted January 13, 2023 Share Posted January 13, 2023 15 minutes ago, eaglescout526 said: Can’t be, the white one is the horn relay Headlamp Delay Module. 2 minutes ago, 87MJTIM said: How about the radio/LED clock display relay C354? Yes for the Borq Cube relay. Link to comment Share on other sites More sharing options...
eaglescout526 Posted January 13, 2023 Share Posted January 13, 2023 10 minutes ago, Ωhm said: Headlamp Delay Module. Wha? No the headlamp delay module is the silver 4 prong one that is tucked up next to the steering column if installed. Link to comment Share on other sites More sharing options...
Limeyjeeper Posted January 13, 2023 Share Posted January 13, 2023 That is some brutal wiring in that fuse box. Surprised the truck didn't burn to the ground. Adding non fused circuits into hot side of spare slots on the fuse box is never a good idea Link to comment Share on other sites More sharing options...
CO MJ Posted January 13, 2023 Author Share Posted January 13, 2023 Thanks for all the help! So it sounds like everything is stock anyways other than those wires coming out of the fuse box and the thing on my roof. I'll try again tomorrow to track down where those wires go. Link to comment Share on other sites More sharing options...
Ωhm Posted January 13, 2023 Share Posted January 13, 2023 11 hours ago, eaglescout526 said: Wha? No the headlamp delay module is the silver 4 prong one that is tucked up next to the steering column if installed. I was guessing the blue box one as the headlamp delay module. Link to comment Share on other sites More sharing options...
CO MJ Posted January 13, 2023 Author Share Posted January 13, 2023 Is it pretty typical for cars from this era to have numerous electrical components just dangling beneath the dash? That seems crazy to me Link to comment Share on other sites More sharing options...
ghetdjc320 Posted January 13, 2023 Share Posted January 13, 2023 8 minutes ago, CO MJ said: Is it pretty typical for cars from this era to have numerous electrical components just dangling beneath the dash? That seems crazy to me No. The previous owner/s made a mess of things. Most of those items mount to the harness itself normally with zip ties and tape. What starts to happen is some component fails and instead of tracking down the simple problem (like a connector not making good contact), someone will just determine they have bad wiring and run a jumper to bypass an issue. not the way to go. For some of those added components, someone needs to study relays for a few minutes along with the Jeep’s stock power distribution. Link to comment Share on other sites More sharing options...
eaglescout526 Posted January 13, 2023 Share Posted January 13, 2023 45 minutes ago, Ωhm said: I was guessing the blue box one as the headlamp delay module. Nope. That’s the blue chime box that lets you know the headlamps are on after turning off the Jeep and that your unbuckled and your key is in the ignition with the door open. Link to comment Share on other sites More sharing options...
Ωhm Posted January 13, 2023 Share Posted January 13, 2023 Understood. Link to comment Share on other sites More sharing options...
CO MJ Posted January 13, 2023 Author Share Posted January 13, 2023 2 hours ago, ghetdjc320 said: No. The previous owner/s made a mess of things. Most of those items mount to the harness itself normally with zip ties and tape. What starts to happen is some component fails and instead of tracking down the simple problem (like a connector not making good contact), someone will just determine they have bad wiring and run a jumper to bypass an issue. not the way to go. For some of those added components, someone needs to study relays for a few minutes along with the Jeep’s stock power distribution. The various relays just hang there though? They aren't normally mounted in a block bolted to the frame anywhere? Link to comment Share on other sites More sharing options...
ghetdjc320 Posted January 13, 2023 Share Posted January 13, 2023 1 hour ago, CO MJ said: The various relays just hang there though? They aren't normally mounted in a block bolted to the frame anywhere? Not those relays. They are strapped to the harness. It’s nothing odd though, many oem harnesses do that. There wasn’t really any relay center inside the cab. Link to comment Share on other sites More sharing options...
eaglescout526 Posted January 13, 2023 Share Posted January 13, 2023 Welcome to the 80’s and early days of sophisticated car wiring! Link to comment Share on other sites More sharing options...
CO MJ Posted January 14, 2023 Author Share Posted January 14, 2023 Update! Black box on the roof is just an antenna. I see that hacked off lever is connected to what I guess is the clutch master cylinder? Whatever, it definitely appears that this truck has been converted from a manual to automatic. Removing those not stock wires from the fuse box results in my transmission being stuck in like third gear, very little power going to wheels. I don't know squat about how transmissions work and their wiring so will be reading up there. Any ideas what those wires might specifically be, and any suggestions on cleaning things up to better match stock automatic wiring? Link to comment Share on other sites More sharing options...
CO MJ Posted January 14, 2023 Author Share Posted January 14, 2023 And another one: I'm trying to use the acc connection on the fuse box to power my window motors. I get battery voltage when I turn the ignition on but as soon as I connect to my door motors the voltage will drop to 0 or even weirder, like 3-6v. The door power connected to an external power supply works just fine. The fuse doesn't blow. That's weird right? I'm having trouble finding a diagram of where the acc power comes from, but I'd assume a wire from the battery, to the ignition switch, to the fuse box. No other magic involved. Unless maybe the ign turns on an acc relay, but I don't see mention of that anywhere. Link to comment Share on other sites More sharing options...
Ωhm Posted January 14, 2023 Share Posted January 14, 2023 Window Motors are high current circuits. Check IGN SW C267_A. Could have voltage drop at IGN SW. 88 Electrical Manual included. Used for 89's. 88 Electrical Manual _mj1988electricalmanual_1.pdf Link to comment Share on other sites More sharing options...
CO MJ Posted January 14, 2023 Author Share Posted January 14, 2023 23 minutes ago, Ωhm said: Window Motors are high current circuits. Check IGN SW C267_A. Could have voltage drop at IGN SW. 88 Electrical Manual included. Used for 89's. 88 Electrical Manual _mj1988electricalmanual_1.pdf Thanks! Will check this tomorrow. FWIW the voltage drops when the wires are connected, before I ever push the up/down switch. The radio also will sometimes just cut off while driving so bad connection feels likely Link to comment Share on other sites More sharing options...
CO MJ Posted January 16, 2023 Author Share Posted January 16, 2023 So it looks like that mess is largely because whoever converted the transmission did not put the TCU where it's supposed to go under the glove box, and instead put it on the driver side. Does anyone know if the connectors for the automatic are present on the engine control harness for a manual? C113, C234. From what I'm searching it looks like they are not, and that's why I have this spaghetti mess and the PO has just run all the connections by hand instead of swapping out the harness. If that's the case, and I have all the connectors, if it's worth moving the box to it's correct location and building my own harness, or if I should go find the right harness, or just clean up those fuse box connections and call it a day as everything seems to work anyways. Link to comment Share on other sites More sharing options...
CO MJ Posted January 17, 2023 Author Share Posted January 17, 2023 Here's another one; on the fuse box diagram and power distribution diagrams is the "power window circuit breaker". I don't see anything of the sort on my fuse box, is it physically built into the panel? In the schematic there is a single wire, but there are two arrows on the fuse box diagram, pointed at 3 different connectors. Does anyone know where each of the pins actually go? If someone has power windows and wouldn't mind snapping a picture of the connector that would also be very helpful! Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now