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Bosch relay question.
12-06-2006, 06:12
Post: #4
Bosch relay question.
You are correct here:
"I have continuity between terminals 30 and 87A."
and here:
"I don't have continuity between terminals 30 and 87."
and here:
"the continuity between 30 and 87a will go away and I will have
continuity between 30 and 87."

THIS ASSUMPTION MAY FOOL YOU INTO BELIEVING YOU HAVE A BAD COIL.
"If I don't have continuity between 85 and 86 how does the coil
become energized."

If you are reading on a low Ohms scale, (low resistance scale)you may
or may not see any movement because of the coil resistance being
higher than the scale you are reading. In this case, an when in
doubt, move up to a higher and yet higher scale. If you do not read
anything on the highest scale the coil is open and the relay is shot.

I was taught to start on the highest scale and then move to lower
scale is suspicious.

65-86 is the relay coil
30 is the common connection to
87A the normally closed contact
87 the nomally open contact.
bob janes, greenville, sc







"I understand that when the coil on terminals 85 and 86 is energized"
(Energized meaning 12 volts is applied)


--- In WanderlodgeForum@yahoogroups.com, Pete Masterson
wrote:
>
> See
> < http://www.classictruckshop.com/clubs/ea...cts/bosch/
> relay.htm> for info about how a Bosch relay is put together.
>
> 85 and 86 control the magnet coil and, presumably, must have
> continuity to operate.
> 30 and 87a have continuity when there is _no_ power to 85 and 86.
> 30 and 87 will only have continuity when there -is- power to 85 and
86.
>
> Pete Masterson
> aeonix1@...
> '95 Blue Bird Wanderlodge WBDA 42'
> El Sobrante, CA
>
>
>
>
> On Dec 6, 2006, at 8:22 AM, toddad538 wrote:
>
> > I have a question regarding a Bosch 5 terminal relay.
> >
> > I have continuity between terminals 30 and 87A.
> > I don't have continuity between terminals 30 and 87.
> > I understand that when the coil on terminals 85 and 86 is
energized
> > the continuity between 30 and 87a will go away and I will have
> > continuity between 30 and 87.
> >
> > Just for fun I tried checking for continuity between terminals 85
> > and 86 and there is none.
> >
> > Question:
> > If I don't have continuity between 85 and 86 how does the coil
> > become energized.
> >
> > I would think that there must be continuity between 85 and 86 to
> > complete the circuit thus energizing the coil.
>
>
>
> [Non-text portions of this message have been removed]
>
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Messages In This Thread
Bosch relay question. - toddad538 - 12-06-2006, 04:22
Bosch relay question. - Pete Masterson - 12-06-2006, 05:25
Bosch relay question. - Wilhelmus Schreurs - 12-06-2006, 05:26
Bosch relay question. - one_dusty_hoot - 12-06-2006 06:12



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