im stumped
Tuned
Joined: Sep 2013
Posts: 368
Likes: 0
From: Virginia Beach/Wisconsin
Actually, what would be the easiest for you probably would be to find an 89 in the junk yard, get the engine harness off of it and transfer it into your bronco. You'd be able to check everything over as you re-installed it, and KNOW what you're dealing with then. Kinda remove all doubt, so to say.
Lead Driver
Joined: Aug 2006
Posts: 5,670
Likes: 13
From: Sand Lake, MI
Yea you probably should go over the wires make sure everything looks right, the fact you unplugged the engine harness and still had 4volts output pin 29 tends suggest that isn't the problem.
Might be yea but seams unlikely as it sounds like they used the 89 harness on the engine, have to do something pretty stupid not to mention bunch more work to screw that up.
In post 24 you stated "So i stuck it back in my daily driver and checked it. Well it only put out . 1 volts", not real clear there.
Are you saying you put the computer from this truck in your daily driver and it put out one volt on pin 29?
Daily driver the same year truck?
Might be yea but seams unlikely as it sounds like they used the 89 harness on the engine, have to do something pretty stupid not to mention bunch more work to screw that up.
In post 24 you stated "So i stuck it back in my daily driver and checked it. Well it only put out . 1 volts", not real clear there.
Are you saying you put the computer from this truck in your daily driver and it put out one volt on pin 29?
Daily driver the same year truck?
Thread Starter
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Senior User
Joined: Jan 2007
Posts: 186
Likes: 1
From: watford, ontario
My dd is A 90 f150 short box 4x4 5 spd 5.0. Love that truck. I did the same test on this truck whatched for voltage on pin 29 coming from the pcm with the o2 harness unplugged and had a reading of . 03 volts up to . 10 volts. So up to one tenth of a volt. I then installed that pcm in the bronco but it to put out 4 volts So that makes me say wiring problem
Senior User
Joined: Mar 2014
Posts: 433
Likes: 0
From: southern maryland
find the circuit that made the 4 volts go away and try un doing any connectors near that circuit and try to isolate it to one circuit or group of wire. and i do not think any of us ever asked you what type of engine you had. and try swapping computers the other way if you can
Lead Driver
Joined: Aug 2006
Posts: 5,670
Likes: 13
From: Sand Lake, MI
My dd is A 90 f150 short box 4x4 5 spd 5.0. Love that truck. I did the same test on this truck whatched for voltage on pin 29 coming from the pcm with the o2 harness unplugged and had a reading of . 03 volts up to . 10 volts. So up to one tenth of a volt. I then installed that pcm in the bronco but it to put out 4 volts So that makes me say wiring problem
Ok yea that's gonna be tough to find.
Setting up meter where you can see it shaking the **** out of sections of the harness pulling pushing it around see if you get a reaction in hopes of narrowing down where to take closer look.
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Senior User
Joined: Jan 2007
Posts: 186
Likes: 1
From: watford, ontario
yup ill try to do the good old ford wiggle test this weekend and if i dont find anything think im gona disconect the pcm and bust all the retaining clips off hook it back up and unplug each wire one at a time while watching the 4 volts
and ya iv swapped pcms the other way too bronco pcm to dd and it didnt put out 4 volts
and ya iv swapped pcms the other way too bronco pcm to dd and it didnt put out 4 volts
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Lead Driver
Joined: Aug 2006
Posts: 5,670
Likes: 13
From: Sand Lake, MI
yup ill try to do the good old ford wiggle test this weekend and if i dont find anything think im gona disconect the pcm and bust all the retaining clips off hook it back up and unplug each wire one at a time while watching the 4 volts
and ya iv swapped pcms the other way too bronco pcm to dd and it didnt put out 4 volts
and ya iv swapped pcms the other way too bronco pcm to dd and it didnt put out 4 volts
Senior User
Joined: Mar 2014
Posts: 433
Likes: 0
From: southern maryland
you know the wire has 4 volts and you know it deals with the oxygen sensor so do a wiggle test all you want but you have not verified what type of issue a short to ground or a power feed making its way on to the o2 wire and its their all the time so you need to get more specific. if you took the f150 engine computer and installed it in the bronco and the ghost voltage went away then their is a issue right their. and if you take the signal wire out of the picture then the 4 volts will go away. no blown fuses and your test light did not light so the ground issue has been addressed. and you need to be careful not to damage your new sensor a volt meter needs some power to make it read.
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Senior User
Joined: Jan 2007
Posts: 186
Likes: 1
From: watford, ontario
well i think i got it so as planed i went home and cleaned up the grounds on either side of the rad ( again) and no change on the 4 volts on pin 29 . I then did the wiggle test while watching the meter and no change . i then decided to double check the pcm hego ground and ya has ground its good . i did discover that i also had 4 volts on the hego ground from the pcm to the back of the intake ( so i hade a ground but a poor one ) so i grounded that wire and then lost my 4 volts on pin 29, ran the self test and the code 41 is GONE finally
i dont know how i missed that i know i checked that wire at the pcm and had ground, but o well its fixed for now thanks for all the help
i dont know how i missed that i know i checked that wire at the pcm and had ground, but o well its fixed for now thanks for all the help
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