<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=utf-8"><meta name=Generator content="Microsoft Word 15 (filtered medium)"><style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri",sans-serif;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:#0563C1;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:#954F72;
text-decoration:underline;}
p.msonormal0, li.msonormal0, div.msonormal0
{mso-style-name:msonormal;
mso-margin-top-alt:auto;
margin-right:0cm;
mso-margin-bottom-alt:auto;
margin-left:0cm;
font-size:11.0pt;
font-family:"Calibri",sans-serif;}
span.EmailStyle19
{mso-style-type:personal-reply;
font-family:"Calibri",sans-serif;
color:windowtext;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:72.0pt 72.0pt 72.0pt 72.0pt;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]--></head><body lang=EN-GB link="#0563C1" vlink="#954F72"><div class=WordSection1><p class=MsoNormal><span style='mso-fareast-language:EN-US'>I think that’s a diode in there. These things only work one way. See attached. (written for local club in UK).<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-US'>I’d guess that you’ve got identical pumps but that, if you removed the diodes, you’d see that one was hooked up the other way round.<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-US'>Simon<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-US'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span lang=EN-US>From:</span></b><span lang=EN-US> Healeys [mailto:healeys-bounces@autox.team.net] <b>On Behalf Of </b>hspethmann@t-online.de<br><b>Sent:</b> 22 June 2018 23:18<br><b>To:</b> healeys@autox.team.net<br><b>Subject:</b> [Healeys] SU fuel pump polarity<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p style='margin:0cm;margin-bottom:.0001pt'><span style='font-size:10.0pt;font-family:"Arial",sans-serif;color:black'>My Healey:</span><o:p></o:p></p><p style='margin:0cm;margin-bottom:.0001pt'><span style='font-size:10.0pt;font-family:"Arial",sans-serif;color:black'>BJ8 MKIII 1964</span><o:p></o:p></p><p style='margin:0cm;margin-bottom:.0001pt'><span style='font-size:10.0pt;font-family:"Arial",sans-serif;color:black'># L27347</span><o:p></o:p></p><p style='margin:0cm;margin-bottom:.0001pt'><span style='font-size:10.0pt;font-family:"Arial",sans-serif;color:black'>pos. earth</span><o:p></o:p></p><p style='margin:0cm;margin-bottom:.0001pt'> <o:p></o:p></p><p style='margin:0cm;margin-bottom:.0001pt'><span style='font-size:10.0pt;font-family:"Arial",sans-serif;color:black'>Fuel pump for the last 20 years:</span><o:p></o:p></p><p style='margin:0cm;margin-bottom:.0001pt'><span style='font-size:10.0pt;font-family:"Arial",sans-serif;color:black'>SU AZX1307</span><o:p></o:p></p><p style='margin:0cm;margin-bottom:.0001pt'><span style='font-size:10.0pt;font-family:"Arial",sans-serif;color:black'>now with a slow, but steady clicking every 15 to 20 sec , when ignition is on.</span><o:p></o:p></p><p style='margin:0cm;margin-bottom:.0001pt'> <o:p></o:p></p><p style='margin:0cm;margin-bottom:.0001pt'><span style='font-size:10.0pt;font-family:"Arial",sans-serif;color:black'>I thought, the easiest solution is to change the pump with a spare pump I have in my trunk for about the same time as the first one. Both pumps look the same on the outside. Both pumps are wrapped in black tape. But the label on the box of the spare pump says: AZX1307 neg. earth. </span><o:p></o:p></p><p style='margin:0cm;margin-bottom:.0001pt'><span style='font-size:10.0pt;font-family:"Arial",sans-serif;color:black'>In the archives I found a very instructive contribution by Steve Russel from Aug 2009. And it ended with the words: "A picture would be worth a lot of words right now."</span><o:p></o:p></p><p style='margin:0cm;margin-bottom:.0001pt'><span style='font-size:10.0pt;font-family:"Arial",sans-serif;color:black'>So I removed the cap on both pumps to see if there is any difference in the wiring and took a picture, attached to this mail.. Both pumps look the same inside. You see the old pump on the left, the new one on the right. Under the cap you see a piece that looks like a capacitor, labeled as BZX1013. But following the explanation with terminal 1, 2 and 3 clockwise beginning with the power input stud and ending with the internal ground terminal I suppose the "capacitor" is a diode. But when there is no difference in wiring between the old and the new pump, why could it be, that the old one looking like a neg. earth ran 20 years in a car with pos. earth?</span><o:p></o:p></p><p style='margin:0cm;margin-bottom:.0001pt'><span style='font-size:10.0pt;font-family:"Arial",sans-serif;color:black'>I'm confused and hoping for your wisdom to shed some light on the problem.</span><o:p></o:p></p><p style='margin:0cm;margin-bottom:.0001pt'> <o:p></o:p></p><p style='margin:0cm;margin-bottom:.0001pt'><span style='font-size:10.0pt;font-family:"Arial",sans-serif;color:black'>Best</span><o:p></o:p></p><p style='margin:0cm;margin-bottom:.0001pt'><span style='font-size:10.0pt;font-family:"Arial",sans-serif;color:black'>Achim</span><o:p></o:p></p><p style='margin:0cm;margin-bottom:.0001pt'> <o:p></o:p></p><p class=MsoNormal><o:p></o:p></p></div></body></html>