Date: Sat, 27 May 2017 17:23:58 -0400
Reply-To: Stephen Grisanti <bike2vcu@YAHOO.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Stephen Grisanti <bike2vcu@YAHOO.COM>
Subject: Re: Only 5V at Temp II sensor?
In-Reply-To: <CAOXGjpkRSKOJ4J4WAuFnUm02xJyHhL4JXgKXjK4ZuDQsa7WrUg@mail.gmail.com>
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I have bypassed bad terminals like that when the remaining connections on such a block were still good. Run the "bad" wire past both sides of the connector to new m/f spade connectors.
Stephen
Mobile
> On May 27, 2017, at 5:15 PM, George Gaudette <gcgaudette@GMAIL.COM> wrote:
>
> I failed to reply all -- sorry to David for the double post.
>
> Also, I should add that the 67 ohms resistor is supposed to approximate the
> resistance produced when the sensor senses coolant at normal operating
> temperatures. More or less.
>
> Now once more, with feeling...
>
> Once Mark pointed out my mistake I disconnected the **correct** sender and
> found the positive wire broken at the spade, with lots of corrosion. With
> the wire stripped a little I got 9V to the brown wire's spade (tough to get
> the test lead to touch it well though) and 10V when grounding to a nearby
> ground strap instead.
>
> I hooked up the "67 ohms" resistor that I fashioned and the temp needle
> moved for the first time in a long time -- slightly above dead center over
> the blinkenlight, which I consider normal.
>
> Now I've gotta figure out how to get that orphaned spade out of the
> connector, or replace the connector. The back of the spade is completely
> corroded away.
>
> Anyhow the problem is isolated, so I think I'm well on my way.
>
> Thanks again.
>
> On Sat, May 27, 2017 at 5:12 PM, George Gaudette <gcgaudette@gmail.com>
> wrote:
>
>> Thanks David!
>>
>> Once Mark pointed out my mistake I disconnected the **correct** sender and
>> found the positive wire broken at the spade, with lots of corrosion. With
>> the wire stripped a little I got 9V to the brown wire's spade (tough to get
>> the test lead to touch it well though) and 10V when grounding to a nearby
>> ground strap instead.
>>
>> I hooked up the "67 ohms" resistor that I fashioned and the temp needle
>> moved for the first time in a long time -- slightly above dead center over
>> the blinkenlight, which I consider normal.
>>
>> Now I've gotta figure out how to get that orphaned spade out of the
>> connector, or replace the connector. The back of the spade is completely
>> corroded away.
>>
>> Anyhow the problem is isolated, so I think I'm well on my way.
>>
>> Thanks again.
>>
>> -George
>>
>> On Sat, May 27, 2017 at 5:03 PM, David Beierl <dbeierl@attglobal.net>
>> wrote:
>>
>>>
>>>
>>> On Sat, May 27, 2017 at 2:45 PM, George Gaudette <gcgaudette@gmail.com>
>>> wrote:
>>>
>>>> Hi Volks,
>>>>
>>>> '90 water-cooled automatic camper here.
>>>>
>>>
>>> Thank you. :)
>>>
>>>>
>>>> My coolant temp needle stopped moving entirely some time ago. The
>>>> coolant
>>>> blinky light works normally (blinks initially on startup then goes out,
>>>> and
>>>> has recently blinked for low coolant level).
>>>>
>>>
>>> Good. Gauge doesn't have leaky timing cap, and coolant level controller
>>> is successfully simulating overheat in short pulses that activate the
>>> blinker but don't materially affect the gauge itself.
>>>
>>>>
>>>> ...which is to say I hoped to validate that the temp gauge is in working
>>>> order (including the wiring to it).
>>>>
>>>> The first thing to do was to check that there is 10V across those wires.
>>>> Instead I found there was about 4.9V. I tried with the negative lead
>>>> touching a ground point instead of the brown wire, and got 5.3V.
>>>>
>>>
>>> The ECU supplies five volts to Temp-II through an ?8132 ohm? resistor,
>>> creating a voltage divider with the variable resistance of the Temp-II
>>> sender. This however has nought to do wi' t'gauge -- the problem there is
>>> that one of the fly rods has outta skew on t'treadle. Or more likely that
>>> the sender or connector is open, of course. It's the black one around the
>>> corner from the blue Temp-II sender which is concerned strictly with engine
>>> operation. 265 ohms to ground should give you the bottom mark, 35 ohms the
>>> beginning of overheat zone and blinking light (light threshold is around 42
>>> ohms IIRC). Grounding the sender lead should make the gauge go up like a
>>> slow rocket, and if you leave it connected, start smelling hot in a minute
>>> or two. No action means either a wiring problem between engine bay and
>>> gauge (but not the panel connector or panel wiring since the low coolant
>>> warning functions) or -- very very unlikely, the gauge heater has gone open
>>> or the needle suspension has failed.
>>>
>>> Yrs,
>>> d
>>>
>>
>>