[T3] '73 Idle Test

[Jim Adney]

On 28 Aug 2019 at 10:26, William Jahn wrote:

>  Jim :
> 
>  I am just going by the Brown Bentley for wiring. So far it's been right as
> far as the wiring diagram and FI wiring go.

I'm going by the Bentley, too. The test wire is there for '72 but gone in '73.

> I want to see if the power relay has any voltage drop between 30/51 and
> 87 since this is where all the ECU power begins. If I see a voltage
> drop there the power relay contacts have high resistance and either I
> need to remove the cover and check and possibly clean the contacts 

While I've never seen a problem with that relay, I have had a similar problem 
with the fuel pump relay, and that's the same part.

> Then move on to connector #20 and check both wire #16 and #24 to see if
> there is high resistance in either one or both which will lower the ECU
> voltage. 

Reasonable.

> Any one of these could be what's causing the issue I have which is what
> you pointed out one post back. I'm hoping this is where the issue is
> and could be I never looked at connector #20 and after over 40 years
> the 1/4" terminals inside this now black plastic once clear
> connector/insulator may not have broken wire strands yet the brass
> terminals inside exposed to the weather might be in real sorry shape
> and have high resistance. 

While it seems to be extremely popular to take spade connections apart and 
clean them, time and weather do not affect them nearly as much as people 
must think. A connection that's never been apart is probably fine, while one 
that's been disconnected many times may be suspect. The key is in how 
tight it is: If it's hard to get apart, it's good; if it slips apart easily, it's poor and 
cleaning is probably not going to help. The problem is that you can certainly 
clean the male parts, but the area that makes most of the female contact is 
nearly impossible to reach without damaging the contact area.  

The key is that the contact area is under the end of the "curl" of the female 
connector. That's gas tight if it was clean when connected. It will stay good 
as long as it stays tight.

OTOH, broken strands can be a real problem, but this only tends to happen 
on wires that have been treated roughly.

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