RPM Gauge is flickering

[Ron]

What resistor do you need?

Been a while so I would have to dig to get the number. You may recall, I PMed you about it being made with a cut/gap down through the center of it?

...Just remembered it was 160 MPH.

[Bitsyncmaster]

Been a while so I would have to dig to get the number. You may recall, I PMed you about it being made with a cut/gap down through the center of it?

...Just remembered it was 160 MPH.

You could always use a few resistors to get an exact value you want. Or even use a trim pot. Most of the metal film resistors are 1% tolerance and are stocked in many values. You can probably calibrate it on the bench. It depends what the threshold of the tach signal is. I have built a signal generator for testing the idle ECUs that has two calibrated values 700 RPM and 850 RPM with a 400 volt signal level.

[Ron]

You could always use a few resistors to get an exact value you want. Or even use a trim pot. Most of the metal film resistors are 1% tolerance and are stocked in many values. You can probably calibrate it on the bench. It depends what the threshold of the tach signal is. I have built a signal generator for testing the idle ECUs that has two calibrated values 700 RPM and 850 RPM with a 400 volt signal level.

...it is so touchy that I could run a moist finger along the cut and make it read correctly.

Schematic1669 160 Tac.jpg
PM me your address if you want to play with it.

[mburshtain]

Before ordering parts just try plugging and unplugging the connector to the flexible PCB. It could just be a bad connection and plugging and unplugging the connector will clean the connections up and maybe fix the problem.

David, you were right !
I removed the binnacle cleaned all the connectors and tested it while driving. Working great, no more flickering.

Unfortunately, I broke the trip reset shaft during the binnacle removal.
How hard is to replace it? I ordered one from DeloreanGo.

[mburshtain]

Thanks to Christian Williams I replaced the trip reset shaft.
It’s a nice project, going really deep in the gauge...

[Mark D]

Thanks to Christian Williams I replaced the trip reset shaft.
It’s a nice project, going really deep in the gauge...

My car's had a broken trip reset shaft since I bought it back in 2008 and it even came with a new replacement. I just never seem to get around to fixing it.

It looks like a fun project though. I actually kind of enjoy working on detailed/intricate projects like that vs. the rusty knuckle busting bolts I've been dealing with on my daily driver.

After seeing your pics I think I might dive into it this spring.

[Jonathan]

My car's had a broken trip reset shaft since I bought it back in 2008 and it even came with a new replacement. I just never seem to get around to fixing it.

It looks like a fun project though. I actually kind of enjoy working on detailed/intricate projects like that vs. the rusty knuckle busting bolts I've been dealing with on my daily driver.

After seeing your pics I think I might dive into it this spring.

You already have a copy of the DMCH instructions?

DMCH - Trip reset shaft replacement.pdf

[David T]

While you are inside make sure none of the plastic posts have broken off. On more than one car I found at least one broken and because there is a metal clip on it, it got attracted to and jammed up the speedometer causing several angle drives to fail. Glad to hear the tach fix was cheap and easy. Replace all of the bulbs while you are in there too.

[Mark D]

You already have a copy of the DMCH instructions?

DMCH - Trip reset shaft replacement.pdf

I think I have a paper copy buried in a binder somewhere, but the PDF will be helpful, Thanks