[TR] Perplexing A-Type OD Problem

andrew uprichard auprichard at uprichard.net
Sat Jun 27 06:31:29 MDT 2020

Sorry - Randall is in Kindred hospital, Paramount, CA


From: andrew uprichard <auprichard at uprichard.net> 
Sent: Saturday, June 27, 2020 8:06 AM
To: 'Bill Brewer' <billbrewer59 at yahoo.com>; 'Triumphs List'
<triumphs at autox.team.net>
Subject: RE: [TR] Perplexing A-Type OD Problem


I recently went through FOUR aftermarket voltage regulators on a TR4.  They
came from different vendors and lasted anywhere from a few minutes to a few
weeks.  I sourced an original from Marv Gruber and it has worked fine ever
since.  What are the chances you could get your hands on a nice original


Randall Young is in a rehab hospital (Kindred hospital in Pasadena)
following a stroke.  I have spoken to him several times and encouraged him
to comply with the physical therapy as there were so many TRs waiting for
his advice!  It has been a bad year for him - his father died just a few
months ago.


Andrew Uprichard

Jackson, michigan


From: Triumphs <triumphs-bounces at autox.team.net
<mailto:triumphs-bounces at autox.team.net> > On Behalf Of Bill Brewer
Sent: Friday, June 26, 2020 10:00 PM
To: Triumphs List <triumphs at autox.team.net <mailto:triumphs at autox.team.net>
Subject: [TR] Perplexing A-Type OD Problem


Hi Listers,

     I was on a trip driving my TR3 that has a TR4 overdrive trans in it.
The OD had been working fine and then suddenly nothing would happen when I
threw the switch. I checked the relay with a test lamp and the C2 output
terminal (yellow/purple wire) lights up fine but the solenoid wouldn't
actuate. I tested the solenoid (Moss - aftermarket) on my workbench and it
seems to pull in fine. It probably only has 5,000 miles on it and looks
almost new. I put it back in the car and it doesn't actuate. I ran a new
wire straight from the C2 terminal on the relay to the installed solenoid
and it still doesn't actuate, although I can move the actuation lever by
hand. Evidently the solenoid is bad again. It seems like I go through OD
solenoids fairly regularly. Randall (does anyone know how he is doing???)
had me install a small "bounceback resistor" on the from the C2 output
terminal on the relay to ground to eliminate bounceback voltage spikes. Any
idea why I would be going through solenoids so regularly? I seem to change
them out about every 10,000 miles.

     Could it be a grounding issue for the solenoid? It seems like there
would be plenty of electrical continuity from the transmission to the engine
and chassis, so that shouldn't be it.

     Thanks in advance,


     -Bill Brewer

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://autox.team.net/pipermail/triumphs/attachments/20200627/c32c27c4/attachment.htm>

More information about the Triumphs mailing list