[T3] On my 73 square

Jim Adney jadney at vwtype3.org
Thu Sep 12 05:24:03 PDT 2019

On 11 Sep 2019 at 21:10, William Jahn wrote:

>  I do know the head temp sensor in the car now does not always read the
> same resistance at the same temp and when I removed it I could see a
> dark area under that whitish plastic cover and when I pulled the cover
> back I could see an area just above the top of the sensor where the
> insulation was one , no broken strands yet they were dull copper not
> bright clean so perhaps that might cause an issue . 

The missing insulation won't cause a problem unless it allows the center 
conductor to short to ground on the steel crimp. That will bring you to a halt 
very quickly, but is seldom a problem except on the '68-9 cars where that 
sensor is cramped under the #4 exhaust port. On those engines the wire is 
forced to make a hard right angle turn just past the crimp, and they can short 

Surface corrosion on the copper strands won't add enough resistance to be 
measurable to your instruments, or to matter to our FI. If water has gotten 
down into the sensor element itself, that could cause an increase in 
resistance, or an intermittent problem, because the sensor element is just a 
tiny little puck with contact made by spring pressure on each end.

Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA

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