Linkman Posted June 9, 2006 Share Posted June 9, 2006 On my Contour -- '98 (built 9/97) V6 ATX w/ 98K mile. No mods at all, only work I've done since buying her in Feb was replace the water pump. Driving north on I-71 on Saturday near Strongsville, OH and 110 miles from home, when the engine just STOPS. Cold. All the needles on the dash immediately drop to zero (so even though I'm coasting, the MPH reads 0). I manage to coast to the side. Eventually find that fuse #9, blue 20A, for the PCM is blown. Call a friend, they bring a new fuse, it blows as well on the first turn of the key. Car towed to next exit (Center Towing, Strongsville, OH gets a :thumbsup: ), and then girlfriend's father trailers it the 110 miles home for me (Thank you!). Now it's on the street in front of the house, and I need to find the short. The little that I've found searching is the fuse blowing on startup, I haven't seen an example of one blowing while driving (after nearly two hours of trouble free driving). Other than grabbing my multimeter, and my Ford CD, are there any hints about where to start? Tracing the wiring harness is going to be a royal PITA, and any shortcuts are most appreciated. I have disconnected all of the following load devices: ATX solenoid plug EVR solenoid plug MAF plug IMRC plug A/C WOT relay PCM plug under P/S reservoir EVAP canister plug IAC plug The short on pin 3 of the PCM relay remains. Only load device I didn't disconnect was the VSS plug. I jacked up the 'Tour and found the VSS by hand, but how do you disconnect it? Does the whole sensor need removed? That ain't happening on the street! Is it my luck the short is the last load device I can't get to (VSS) or is it in the harness... somewhere... Since it happened while the car was cruising on the highway, any suggestions what might have gone poof at that time, as a starting point? Thanks for any insight Link to comment Share on other sites More sharing options...
BuckeyeSVT Posted June 9, 2006 Share Posted June 9, 2006 On my Contour -- '98 (built 9/97) V6 ATX w/ 98K mile. No mods at all, only work I've done since buying her in Feb was replace the water pump. Driving north on I-71 on Saturday near Strongsville, OH and 110 miles from home, when the engine just STOPS. Cold. All the needles on the dash immediately drop to zero (so even though I'm coasting, the MPH reads 0). I manage to coast to the side. Eventually find that fuse #9, blue 20A, for the PCM is blown. Call a friend, they bring a new fuse, it blows as well on the first turn of the key. Car towed to next exit (Center Towing, Strongsville, OH gets a :thumbsup: ), and then girlfriend's father trailers it the 110 miles home for me (Thank you!). Now it's on the street in front of the house, and I need to find the short. The little that I've found searching is the fuse blowing on startup, I haven't seen an example of one blowing while driving (after nearly two hours of trouble free driving). Other than grabbing my multimeter, and my Ford CD, are there any hints about where to start? Tracing the wiring harness is going to be a royal PITA, and any shortcuts are most appreciated. I have disconnected all of the following load devices: ATX solenoid plug EVR solenoid plug MAF plug IMRC plug A/C WOT relay PCM plug under P/S reservoir EVAP canister plug IAC plug The short on pin 3 of the PCM relay remains. Only load device I didn't disconnect was the VSS plug. I jacked up the 'Tour and found the VSS by hand, but how do you disconnect it? Does the whole sensor need removed? That ain't happening on the street! Is it my luck the short is the last load device I can't get to (VSS) or is it in the harness... somewhere... Since it happened while the car was cruising on the highway, any suggestions what might have gone poof at that time, as a starting point? Thanks for any insight Quite a weird problem, however I have a curiousity. If I may indulge a possible area of issue - Pull the battery, and then pull the engine fusebox. Underneath the fusebox is an area that can be very problematic on our wiring harnesses and completely out of sight. If I can find the picture of what mine looked like I will attach a photo to what mine looked like at 78K. -Dom Link to comment Share on other sites More sharing options...
Linkman Posted June 13, 2006 Author Share Posted June 13, 2006 Bumping to update, and ask a question... I got back to this last night - managed to disconnect the VSS from above, and found the PCV valve not inserted into its tube at all, so at least one other problem has been fixed. And discovered I'd disconnected the TR sensor, not the ATX hardware unit, so did that correctly this time as well. Unfortunately, neither VSS nor ATX hardware unit was the cause of the short, and those were the last of the PCM load devices to disconnect (yes, I also pulled the fuel pump relay, and the two A/C relays as well). So... time to trace the harness :( I pulled the fuse box, and there is nothing as obvious as your bare wire Dom, but I have a feeling there's something similar buried further down the wire harness. ::sigh:: Lot of boring grunt work ahead. Question -- So now that I have to start unwrapping splices and such to trace the PCM power relay wire, what should I use to rewrap the bundles? I've never had good luck with regular electrical tape, the adhesive softens in the heat. Are there high-temp tapes or some other product? And as always, any hints or tips are appreciated. Link to comment Share on other sites More sharing options...
Terry Haines Posted June 13, 2006 Share Posted June 13, 2006 ...before you get in too deep...check the insulation on wires out of the harness to plugs on TPS,MAP etc etc...any sign of the insulation around the wire cracking up could be your problem.Dispite the 'wiring harness recall/fix' that is shown against 95>97's I have had instances wher 98 cars with a 97 build daye have had the exact same harness problem...and it's an SOB to trace and repair.Disconnect the PCM plug and see if you still have a short.The way you discribe the issue it could be a dead short to ground... Link to comment Share on other sites More sharing options...
Linkman Posted June 29, 2006 Author Share Posted June 29, 2006 Update, and a question on splice locations. Weather, work, and other obligations have finally allowed me to return to this... Where is S59, and S178, on a 98 Contour ATX V6? The Ford Service CD says "S59 engine compartment - center", and "S178 - engine". Any Ford techs know where those are? Do I need to remove the UIM, or get to them from underneath? If so, I'm going to have to find some friends to help me push it up onto the driveway, don't want to do that in the street. Thanks! Link to comment Share on other sites More sharing options...
Terry Haines Posted June 29, 2006 Share Posted June 29, 2006 ...I smell 'suspect wiring'....This will be a pain to track down....but to blow the main fuse like that points me to the battery junction box as Dom pointed out.You will need to go the long route to with the CD etc... Link to comment Share on other sites More sharing options...
Linkman Posted June 29, 2006 Author Share Posted June 29, 2006 ...I smell 'suspect wiring'....This will be a pain to track down....but to blow the main fuse like that points me to the battery junction box as Dom pointed out.You will need to go the long route to with the CD etc... Yeah, it's suspect wiring all right. :why-me: I've managed to narrow down the search though - it's in the harness somewhere south of C3001 - the large black plastic connector mounted on the driver side strut tower - but it's north of C120 - one of the connectors on rear passenger side valve cover, near the strut tower. So it's somewhere in the harness that connects the EVR solenoid / PCM / MAF / VSS / C645 (tranny hardware unit). Which runs behind/below the engine :( The only splices on this part of the harness are S59, and S178, but for some reason the service manuals (while giving location diagrams for every component and connector) don't give a location for the splices beyond the text description I quoted. I'm guessing S59 isn't too far from the C3001 connector, since the MAF power comes off that splice, and I suspect S178 is down low to the rear, since the VSS and hardware tranny unit power come off that one. At least knowing it's north of C120 means I don't have to pull the UIM and look at the injector harness. (Oh, and "south" means away from the fuse box, "north" is toward the fuse box ) Link to comment Share on other sites More sharing options...
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