shaqdaddy86

Hi there, when I bought my 79 Corvette the tachometer was not working so I swapped in a new Wilcox board. The tach now works but it has an odd issue. Without fail, it will read ~250 rpm less at cruise on the second trip of the day. Example: going to work reads 2750 @ 70, going home reads 2500. Any idea why it does this? I have searched the interwebs and can't find anyone with a similar problem. Thanks!

Derek

zwede

The wilcox tach boards had an issue for a while where they would read low when hot. They reportedly fixed that on the newer boards, but maybe you have one of the bad ones.

shaqdaddy86

Thanks- I got mine in Nov of 2012 so maybe it is that issue. I'll email Willcox and see what they have to say.

0Willcox Corvette

That I can tell, the earliest reported issue was 2-04-2013 so yours pre-dates this by a couple of months. It is highly possible it has an issue and from the same batch. While the issue was limited to a small batch, a change was made to correct the issue.

Mail the board to me and I'll test it here and then get you fixed up.

Willcox Inc. Attn: Ernie
123 E. Maple Street
Jeffersonville, Indiana 47130

Tin_Can_Terminator

Digging up an old thread here....

What is the warranty on these Willcox tach boards? Web site doesnt seem to say. I have one acting up on me. Mine was bought in Feb of 13.

Thanks TCT

0Willcox Corvette

The warranty is one year from the date of purchase...

Send me the board (and possibly the tach) and I'll test it for you to see where the issue is, and possibly repair it. Repairing is always cheaper than buying a new board.

Willcox

Tin_Can_Terminator

I sent you an email yesterday. Tonight I will confirm that it is the Tach and not anything else. Im pretty sure its the tach though.

TCT

jasoncrow78

i ordered a pile of parts from ecklers and received a wilcox board. it works much better then the original but still bounces around . and i got the new filter while i was at it ive swapped filters back and forth and tried with out it and it still bounces what am i missing.

0Willcox Corvette

I've not had a defective 1978-1982 board since 2013 but the bounce you describe could be a few things.. It sounds like the old board bounced as well...

1) Loose connection at the tach filter or distributor. (wire breaking possible)
2) The oil in the analog movement missing or an issue with the movement.
3) Something spiking the input signal.

Normally the movement isn't the issue and in the past we've not found that many. But it seems that as these cars age, I'm finding more and more defective movements. This year we've had 4 come into the shop and typically we'd get maybe 1 a year at most.

Willcox

jasoncrow78

it stays steady on idle mostly but when you bump the throttle its all over the place. when you get up to speed it settles down and shows the rpm your at its just getting it there tell it settles down.

0Willcox Corvette

does it do the same with both boards?

jasoncrow78

yes the factory one acted exactly like it.

0Willcox Corvette

Then I'd look for another issue... Check the terminal that plugs into the tach filter for corrosion, check the wire to make sure it's not damaged. It could be the movement in the tach but the only way I'd know that is if you sent the tach to me. All it will cost you is the shipping but I can test it in house.

Willcox

jasoncrow78

soon as its ready for its winter nap ill pull it out and look at shipping it to you then. thanks for your time