LastDeadLast Posted July 5, 2022 Share Posted July 5, 2022 Hi, I'm the new owner of an 85 F150 XLT. 5.0 EFI, 96,000miles. Stock engine as far as I can tell. It's idling a little rough so I pulled the codes and I'm getting a code 18 in continuous memory which translates to: "Loss of tachometer input/IDM circuit failure/Spout circuit grounded" Upon reading up on this fault, the first thing to check was the condition of the wiring. Well it's bit of a mess. The insulation has rotted off the wiring on a few of the leads going to the TFI, SPOUT and coil. I can get replacement pigtails for the TFI and coil but I can't find anything for a 1985 EFI SPOUT connector. I CAN however, find the newer style connector for the 1986+ engines. Will the newer connector work on an 85? From my reading, it looks like the SPOUT connector is used for nothing more than checking timing. Thanks for the help! -Shannon Link to comment Share on other sites More sharing options...
Gary Lewis Posted July 5, 2022 Share Posted July 5, 2022 You don't even need a connector. You could use a switch as you are right, all that does is take the computer's ability to change the timing away and put you on base timing. So if you want a later style connector go for it. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted July 5, 2022 Share Posted July 5, 2022 It's just a jumper. I've seen (and used) a simple inline fuse holder, like this one from Waytek. Link to comment Share on other sites More sharing options...
LastDeadLast Posted July 5, 2022 Author Share Posted July 5, 2022 It's just a jumper. I've seen (and used) a simple inline fuse holder, like this one from Waytek. Thanks everyone for the help! Probably best if I just start a build thread to document all this stuff. -Shannon Link to comment Share on other sites More sharing options...
ratdude747 Posted July 5, 2022 Share Posted July 5, 2022 You don't even need a connector. You could use a switch as you are right, all that does is take the computer's ability to change the timing away and put you on base timing. So if you want a later style connector go for it. I used a spade terminal pair for mine: (old pic, I've swapped some unrelated parts since this was shot last month) I previously had a bullet pair... but it was too hard to disconnect. Spades seem to be a happy medium. Different size crimps are used due to using a replacement TFI connector (which used 14-16 gauge wires for all connections). Link to comment Share on other sites More sharing options...
LastDeadLast Posted July 5, 2022 Author Share Posted July 5, 2022 I used a spade terminal pair for mine: (old pic, I've swapped some unrelated parts since this was shot last month) I previously had a bullet pair... but it was too hard to disconnect. Spades seem to be a happy medium. Different size crimps are used due to using a replacement TFI connector (which used 14-16 gauge wires for all connections). Ratdude, Glad you brought the TFI up. I need to replace mine. I've got a good TFI connect that I can use, but does anyone know where I can source the wiring terminals from? I've searched all over, but can only find the pigtails with the wrong color coding. Thanks, -Shannon Link to comment Share on other sites More sharing options...
ratdude747 Posted July 5, 2022 Share Posted July 5, 2022 Ratdude, Glad you brought the TFI up. I need to replace mine. I've got a good TFI connect that I can use, but does anyone know where I can source the wiring terminals from? I've searched all over, but can only find the pigtails with the wrong color coding. Thanks, -Shannon The one I bought was one of these: https://www.rockauto.com/en/moreinfo.php?pk=4673361&cc=1121432&pt=10623&jsn=4 (STANDARD MOTOR PRODUCTS HP4530) The wires are all black (despite the description) but a good electrical diagram (or the old connector) will say what goes where. Other than the SPOUT I trimmed the new leads back a bit... which is why my SPOUT is a loop. On a lot of Motorcraft pigtails the wires are all black too... the only time I remember getting an off-the-shelf pigtail that had colored wires was the coil plug: https://www.rockauto.com/en/moreinfo.php?pk=939309&cc=1121432&pt=2592&jsn=21 (WVE 1P1091) Maybe WVE makes a TFI connector? I think I was choosing my connector brands based on common warehouses for other things (I was ordering a lot back then as part of an engine rebuild where I decided to fix my hacked up harness the right way). Link to comment Share on other sites More sharing options...
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