daves60 0 Posted February 22 Share Posted February 22 I have 2 of the subject tachometers that do not work. they have 3 or 4 resisters burned out. Looking for an actual wiring diagram or a photo of the circuit board under the rear cover on a good working T-111 so I can get the color codes on the resisters Link to post Share on other sites
alsancle 5,343 Posted February 22 Share Posted February 22 I don't think you are going to get a response in this forum. It is intended for questions related to using the forum. You might try the technical forum, but you should include more information. Link to post Share on other sites
Bloo 1,741 Posted February 23 Share Posted February 23 (edited) The pictures are kind of blurry, and I can't tell for sure but those resistors look like someone filed on them, probably to calibrate the meter, and maybe even at the factory. That would explain why you have two meters that look like that. In the days when carbon composition resistors (like yours) were common, filing was a way to get an exact value without using a potentiometer that might move or get dirty. I have had almost zero luck trying to find schematics for any automotive equipment, and have had to reverse engineer most of the instruments I have fixed. I did get lucky a couple of times with Snap-on and Herbrand. I second the idea of posting this in "technical". This forum you are in is for the computer software that runs the forum, stuff like "Why didn't my pictures post?" and "How do I edit a post title?" and so on. The forum administrators look at questions in here, the automotive people not so much. Best of luck, and I hope you find what you are looking for. Edited February 23 by Bloo (see edit history) Link to post Share on other sites
Larry Schramm 3,307 Posted February 24 Share Posted February 24 (edited) On the resistors that you are looking for, they are +-5%. That is indicated by the GOLD BAND on the one end of the resistor. I would guess that all of the resistors in the test equipment should have gold bands for the close tolerances. If you put in resistors that have just the three or four color bands and no color band like silver or gold, then the resistor value is +- 20%. Silver band is +- 10%. Gold is +- 5%. At least that I what I remember from my electrical classes over 50 years ago. The real question is why the resistors let the smoke out. Did the equipment get over loaded or what? Edited February 24 by Larry Schramm (see edit history) Link to post Share on other sites
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