1998 4.0 SOHC Explorer - Does anyone have a schematic for the auxilliary power ditribution box (the one beneath the air filter box)? Or at least what component each relay supplies, working from the radiator end of the box? I was hoping to find some info on the box cover like you might expect to find on a fuse box cover. But there's nothing there:-( I'm trying to track down the fuses and relays connected with the compressor and controls for the self-levelling suspension. All the fuses in the dash panel and the main distribution box seem OK - I've pulled each one in turn and tested with a meter - so I'm guessing a bad relay might be the reason the air compressor never runs. It does run if I connect a 12V supply directly to it, so I guess the compressor is good.
Oddly enough it did occur to me to look in the owners 'guide'. Unfortunately Ford don't seem to be too keen on divulging technical information to Explorer owners in the UK. We only get a basic 'put oil in here', 'put water in there' type of owners handbook. Haynes is not much use either. I don't seem to be authorised to look at the www.motorcraftservice page you suggested. Perhaps somebody with authorisation could just tell me which relay in the Auxilliary Supply box is for the compressor? Something like '2nd from the back' or 'the one nearest the radiator' will suffice.
Ahhh! It's all so clear now... I found the way into the Motorcraftservice site... Unfortunately page 142 refers to the MAIN power distribution box. I know that all the fuses in there are OK. I've tested all of them. Fuse #9 protects the ARC relay. I understand that the ARC relay is in the AUXILLIARY power distribution box. There are several other relays in there. I'd like to know which one is the ARC relay?
Send me your real address to snipped-for-privacy@mindspring.com and I will send the manual to you. You could also try
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or go in through the motorcraft front page -
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and then click on the "Owner Information" link on the left side of the page. Item 15 is a 50A Maxi Fuse for the Air Suspension Solid State Compressor Relay. It is the 5th fuse from the left on the front row. I am calling the row of relays the back row. The 2 x 6 group of smaller fuses is in the front right corner (these are fuses 1 through 12 - the larger fuses in this line are number from 13 to 19 as you move right to left. There are other fuses related to the air suspension. Fuse 4 is for the Air Suspension Service switch (4 is the second switch from the right on the second row of little fuses from the front). Here is a crude layout -
Relay Relay Relay Relay Relay Relay
29 28 27 26 25 24 23 22 21 20
19 18 17 16 15 14 13 12 10 8 6 4 2 11 9
7 5 3 1
Fuse/Relay Location Fuse Amp Rating Description
1 20A* Trailer Tow Running Lamp Relay, Trailer Tow Backup Lamp Relay
2 10A* Air Bag Diagnostic Monitor
3 30A* All Unlock Relay, All Lock Relay, Driver's Unlock Relay
4 15A* Air Suspension Service Switch
5 20A* Horn Relay
6 30A* Radio, Premium Sound Amplifier, CD Changer, Rear Integrated Control Panel, Sub-Woofer Power (Fuse 3 & Fuse 5)
7 15A* Main Light Switch, Park Lamp Relay
8 30A* Main Light Switch, Headlamp Relay, Multi-Function Switch
9 15A* Daytime Running Lamps (DRL) Module, Fog Lamp Relay
10 25A* I/P Auxiliary Power Socket
11 25A* Console Auxiliary Power Socket
12 10A* Rear Wiper Up Motor Relay, Rear Wiper Down Motor Relay
13 30A** Auxiliary A/C Relay
14 60A** 4 Wheel Anti-Lock Brake System (4WABS) Module
15 50A** Air Suspension Solid State Compressor Relay
16 40A** Trailer Tow Battery Charge Relay, Engine Fuse Module (Fuse 2)
17 30A** Shift on the Fly Relay, Transfer Case Shift relay
18 30A** Power Seat Control Switch
19 20A** Fuel Pump Relay
20 50A** Ignition Switch (B4 & B5)
21 50A** Ignition Switch (B1 & B3)
22 50A** Junction Box Fuse/Relay Panel Battery Feed
23 40A** I/P Blower Relay
24 30A** PCM Power Relay, Engine Fuse Module (Fuse 1)
25 30A CB Junction Box Fuse/Relay Panel, ACC Delay Relay
26 - Not Used
27 40A** Junction Box Fuse/Relay Panel, Heated Grid Relay
28 30A** Trailer Electronic Brake Controller
29 30A** Flip Window Relay, Hybrid Cooling Fan Relay
Thanks for that Ed! I am more than reasonably sure that all the fuses are OK. Do you happen to know where the "Air Suspension Solid State Compressor Relay" lives? The relay, not the fuse? I believe that it is in the Auxilliary Power Supply box, located beneath the air filter box (well, it is on my RHD UK Ex). But which relay is it? None of them are labelled or tagged.
The air compressor relay is not located inside the power distribution box but next to it (at least in american verson) the relay itself sits in a covered holder, you have to remove the cover to see/remove the relay.
If you still need clarification, let me know so can upload a scan
On Wed, 30 Mar 2005 20:49:39 +0000 (UTC), "Simon H"
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