Failed smog, no check engine light

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Oct 4, 2012 | 08:44 PM

#16

leslane

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1988 E250 failed smog test-again

Took a couple days off but here I am, back at it. It appears that there is no voltage to the upstream oxygen sensor between the two pipes feeding the catalytic converter. Does anyone have a schematic of where it gets its power from? I expect there is a fusible link involved somewhere in a wiring harness that will be next to impossible to find but such is life. Any help would be appreciated.

Oct 6, 2012 | 09:22 AM

#17

leslane

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The service advisor at the local Ford dealership tells me that the fusible link is called "Fusible Link "N" and is in the wiring harness. He also said that it would carry no identification on it other than its amperage rating and he had no other information than that, like as to where it might be located, etc. So, the witch hunt begins. Anyone else ever have to do this?

Oct 6, 2012 | 06:33 PM

#18

leslane

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Well, success! The blown fusible link "N" is just about an inch left and behind the master cylinder when you are facing it. There are 2 of them there, I checked them with a voltmeter with the key on and sure enough, one of them had no voltage and was bubbled and the insulation was soft and stretchy. I cut it out and replaced it, made a new 3 wire harness using the 2 socket ends, taped it all up and put it back together. Ready for the smog test next week. My Auto X-Ray code reader gave it a 111 "PASS" reading. So, we will see what shape the converter is in then.