kpinnc 13,149 #1 Posted October 16, 2022 My 520-H has developed a new hiccup. The tach registers nothing until around 3000 rpm. Then it jumps up and reads normally. Anybody else had this happen or have any suggestions? I assume it may just be a worn out guage, but I thought I'd ask the experts first. 1 Share this post Link to post Share on other sites
Ed Kennell 39,819 #2 Posted October 16, 2022 Make sure you have a good clean AC connection at the rectifier. 2 Share this post Link to post Share on other sites
peter lena 8,990 #3 Posted October 16, 2022 @Ed Kennell / @kpinnc agree with you on that , how about insuring a more secure ground to the rectifier area ? alligator clip to known ground point , for a test , personally never count on original ground points , too many spots that do not carry grounding , pete 1 Share this post Link to post Share on other sites
gwest_ca-(File Mod) 11,187 #4 Posted October 16, 2022 Does the tach circuit go through the 9-pin connector that often fails? 1 Share this post Link to post Share on other sites
Ed Kennell 39,819 #5 Posted October 16, 2022 1 hour ago, gwest_ca said: Does the tach circuit go through the 9-pin connector that often fails? It does on my '88 520s Garry. It's the gray wire. 1 Share this post Link to post Share on other sites
kpinnc 13,149 #6 Posted October 16, 2022 Good point fellas on the AC connection and grounding. I'll check that one out. The 520-H is due it's next service anyway. Time to give her a good "once over". 2 Share this post Link to post Share on other sites
