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Re: (ET) ok, not the fusible link




Thanks RJ.
If I know which connections to the relay are supposed to be connected (through the relay) when going forward, I should be able to test to see if the relay is functional or not by just using my ohmmeter to see if those wires are in fact connected? (without needing to take the relay apart) If I find that it's not making that connection, then I could either replace the relay, or try repairing it - but as you mentioned, pulling it out and doing stuff with an old relay with 30+ year old wires connected is likely to lead to other issues, so I'll be prepared to fix others I may cause. To check the relay this way though, I need to figure out which wires coming to it are supposed to be connected (through the relay) when going forward. If they are getting connected as they're supposed to, then presumably the problem is after the relay - probably where it connects to card 1.

Mike

--

--------------------------------------------------------------
Michael S. Briggs
UNH Physics Department
(603) 862-2828
---------------------------------------------------------------

On Tue, 1 Aug 2006, RJ Kanary wrote:

What you can't see is whether or not the contacts are clean, and if they have adequate spring tension to ensure closure. That you will have the verify with fingers and eyeballs.Actually unbolting the relay from the panel may help. But, and there always is a BUT.................the terminals used have a tendency to become brittle. The very act of investigating an issue will cause the problem that you were hoping to solve to now be joined by other gremlins....lots of them.
    So, be prepared and buy those wire ends now. You WILL need them.

----- Original Message ----- From: "Michael S Briggs" <msbriggs alberti unh edu>
To: "Elie, Larry (L.D.)" <lelie ford com>
Cc: <elec-trak cosmos phy tufts edu>
Sent: Tuesday, August 01, 2006 12:12 PM
Subject: Re: (ET) ok, not the fusible link



Larry,
 I *think* the speed control is fine, since it does click as I move
the speed control forward, and I do see the power use meter jump,
indicating *something* is happening (I assume that it's getting armature
current, but no field current, so the motor won't spin - which is why I'm
thinking it's something to do with the forward/reverse relay - either the
relay itself, or a connection between it and the motor (likely card 1). I
didn't have any time yesterday to poke around, but this evening I'll
inspect all the connections between the relay and card 1.
 Hm.... what's the best way to tell if the relay itself is bad? I
can definitely see the relay clicking when putting it in reverse, but it
doesn't seem to do squat when I push forward.

Mike

--

--------------------------------------------------------------
Michael S. Briggs
UNH Physics Department
(603) 862-2828
---------------------------------------------------------------

On Tue, 1 Aug 2006, Elie, Larry (L.D.) wrote:

Did you check the micro-switch on the speed control?  The control is a
hard plastic that eventually wears.  The only difference between forward
and reverse is if one particular micro-switch gets engaged or not.  You
can usually bend the speed control bracket enough to make it work.

Larry Elie


-----Original Message-----
From: elec-trak-bounces cosmos phy tufts edu
[mailto:elec-trak-bounces cosmos phy tufts edu] On Behalf Of Michael S
Briggs
Sent: Monday, July 31, 2006 9:37 PM
To: David C Robie
Cc: elec-trak cosmos phy tufts edu
Subject: Re: (ET) ok, not the fusible link



On Mon, 31 Jul 2006, David C Robie wrote:

BE SURE that all connections under the tractor to the motor especially
the little wires are oK.  You could've hooked something, a branch etc

I'll check 'em. Since it's working in reverse though, shouldn't that
mean
all those connections are fine? My understanding from the schematics is
that the forward/reverse relay reverses the direction of the field (ok,
reverses the direction of the current that makes the field) to swap from

forward to reverse, but the same connections on the motor itself are
used.
No? If that's the way it works, it seems like the connections at the
motor
should be fine. I think.

  If it twer me would check the RTN contacts  and open the kickplate,

Which are the RTN (Return to Neutral, I think?) contacts?

put some WD better yet a good breakfree on all the big relay terminals
then tighten em.

I assume the kickplate is the plate just in front of where you sit? :)
If
so, I've become somewhat familiar with things down there as I've poked
around. I've sprayed the connections with De-Oxit, but haven't loosened
and retightened all the connections.

A bad connection at the 3 big terminals on the armature resistor guard
on
front would cause this too.  Breakfree em and tighten em.

Armature resistor guard? Do you mean the connections to R1 and R2 on the

"screen" above the charger?

Thanks,
Mike

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