VSS - Diesel Forum

gunksvan · 11-29-2007, 09:42 AM

HELP - i am at wits end! my computer looses touch with the differential mounted VSS almost every time i drive my 1995 E350 7.3L. most times it will re-establish comm but maybe not. i have tarced the pair of wires ( twisted pair - yellow and green i believe) leading away from the VSS, cycling any connectors, lookin for faults or corosion and as far as where they go through the firewall to a point behind the dash, i assume to the speedo module, to no avail. i feel like the running path of the wires is clean and the connectors are solid. any ideas? oh i have replaced the sensor - twice. once with an after market part and again with a ford part. thanks for any advice - R

edit: does the VSS give the speedo it's info? if so the problem could be between the speedo and the CPU. the simpdoms of the info lose are eratic auto-tranny shifts and wrong gear choices.

**action4478** · 11-29-2007, 10:06 AM

Mine was the same symptom...

Broken wire, inside the insulation,, had to feel for the break, couldn't see it...

MADVAN · 11-29-2007, 11:16 AM

Check for sensor and wiring on tail of trans.

Bill

**action4478** · 11-29-2007, 11:46 AM

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MADVAN</div><div class="ubbcode-body">Check for sensor and wiring on tail of trans.

Bill </div></div>I missed the E part ,,

Imagine that....

gunksvan · 11-29-2007, 12:07 PM

how did you eventually find that? - where was the break? - what was your correction? thanks - R

gunksvan · 11-29-2007, 12:09 PM

thanks bill, but not sure i understand what i'm lookin for there.

gunksvan · 11-29-2007, 12:11 PM

not hard to imagine - not many E type PSD's - thanks

**action4478** · 11-29-2007, 12:24 PM

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: gunksvan</div><div class="ubbcode-body">how did you eventually find that? - where was the break? - what was your correction? thanks - R </div></div>

Having the wire in your hands ,bending it , you will feel the break , or pulling on it every few inches,, mine was between the frame & the rear axle sensor,might have gotten caught on something,, soldered it , shrink tube for repair,, the break inside the wire ,was making contact most of the time, I finally noticed it most when I hit a bump in the road...

gunksvan · 11-29-2007, 12:40 PM

good - think i'll run a new (temp) pair for conformation - see if that's my problem. that's a tuff one - wonder how they (it) became broken? thanks

MADVAN · 11-29-2007, 01:03 PM

E-series (some years). The sensor on the rear is for ABS and VSS will be on drivers side of trans by the output shaft.

Bill

FULLAUTO · 11-29-2007, 11:18 PM

also use some di electric grease on the connections old connection sometimes lose continuity ,wade

panion · 11-30-2007, 09:12 AM

I second what MADVAN is saying. On my van the sensor on the rear axle is for ABS, the sensor on the tail cone of the transmission is for the speedometer. Are you chasing the wrong wire??

gunksvan · 12-03-2007, 03:48 PM

thanks bill - i'll chk there.