Stewart Warner 990B Tach Module $250

**hubleyman** · #1 10-03-2016, 10:11 PM

Here's another item that just came out of my attic where it has been collecting dust for decades...

SW tachometer Module 990B for use with Tach #970 (according to the label).

Have no idea if it works or how to test it, or what they are really worth...

So let's shoot for $250 which includes shipping within the US.

Post a reply, PM me, email me, whatever works for you. First response gets first dibs. Waiting list for others in case first responder fails to follow through.

Thanks for looking, Charlie

**enio45** · #2 10-04-2016, 04:07 AM

With all due respect - how can you ask for $250.00 and don't know it works? If it does not work, it is worth "0".

Am i missing something here??

**hubleyman** · #3 10-04-2016, 05:11 AM

Because if I offer it for Zero then I will lose money shipping it to somebody...

No, you aren't missing anything here and your point is well taken.

As I stated: "Have no idea if it works or how to test it, or what they are really worth..."

That doesn't mean it's broken or worthless... and it doesn't mean it's a good part either. And I have no idea if they are repairable items, or disposable if they don't work.

But with the knowledge base of this group, someone usually chimes in with info on how to test parts, what items to check, or even if they are worth messing with or just garbage when they don't.

I suppose I could have started a thread asking those kinds of details specifically, but hopefully the potential buyer for something like this already knows more about them then I do and would ask me some questions or to test/check certain things first before spending any money.

With that said, if you happen to have a blue light AM/FM stereo sitting around that you don't know if it works, then you should give it to me for free because it is worth Zero... Right?

[img]<<GRAEMLIN_URL>>/grin.gif[/img]

CamarosRus · #4 10-04-2016, 07:05 PM

Jerry Valentine Kirkland, WA [email protected]
is an expert at ALL the old SW and SUN tachs, etc

**mockingbird812** · #5 10-04-2016, 07:55 PM

check with Jason, aka "SuperNovaSS" as I know that he knows how to test these rascals.

**enio45** · #6 10-05-2016, 02:41 AM

I would have started a thread "how to test the module" - then after you determine that it works, then it might be worth 250.00

But if it did not work - would u still ask 250??

just saying

PS....i would test the blue light radio before offering it for sale as a working unit or not - substantial difference on price.

**SuperNovaSS** · #7 10-05-2016, 03:40 AM

I am not sure how to test one without a tachometer. There is not much to them. The only internal components connect between the IGN and TACH terminals. Below are a couple pictures of what the internals look like. I tried ohm testing across the IGN and TACH terminals and it does not seem to register. I know this one is working because it is the one I use for testing.

I will say that around 75 percent of the pedestal tachs I test are dead but I have never had a dead monitor. I believe the tachs get fried quickly if they are used without a monitor.

Jason

**enio45** · #8 10-05-2016, 02:29 PM

jason, thanks for the inside pics...not much to them - go to Radio shack and buy a capacitor and resistor and your set....unfortunately it takes a bit to get the back cover off if you repair it, and insert the right rivots and get a new sticker for the front - i have bought a few new stickers in the past....

thanks again

camarojoe · #9 10-05-2016, 02:41 PM

As with Jason, I've never had a bad sender, only bad tachs...so odds are good it's fine. I wouldn't tear it apart just to test it.

**Steve Shauger** · #10 10-05-2016, 03:16 PM

I've always had the tach updated with new electronics, and the box itself, had the components removed;it was just a pass through. The updated tachs are more accurate and trouble free.

Based on the components in the box shown its just an RC circuit for pulse conditioning/filter. If you're going to keep the electronics the same I would recommend changing the capacitor in the box.