Symptoms of a bad tach? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Jakes-66-K10 · 06-13-2005, 12:24 PM

How do you know if you have a bad tach? I scored one from a junkyard the other day (along with lots of other cool finds) and this weekend hooked up everything.

This tach kinda works. It "peaks" but won't drop back down. For instance, At first it peaked at idle, I'd rev up the engine and the needle would climb but wouldn't come down. So it sticks wherever the highest RPM setting was.

I wouldn't be suprised if I hooked things up wrong though. The distributor hookup and the tach hookup I'm pretty sure I got right but I may have hooked power up to the wrong spot in the fuse box. I'll have to check when I get home... would this cause a symptom like this?

Jakes-66-K10 · 06-13-2005, 04:59 PM

Bump. No one has seen a problem like this?

jtminton · 06-13-2005, 05:29 PM

Mine seems to stick at zero on acceleration, then jump over and read really high.

**too much stuff** · 06-13-2005, 06:16 PM

I had 2 of them do that, but they seemed to loosen up with more use. I think they get sticky if they sit for awhile. I think if you hooked it up wrong, it wouldn't work at all.

Jakes-66-K10 · 06-13-2005, 08:39 PM

OK. Just to make sure, where do you plug it in at the fuse box?

06-13-2005, 12:24 PM	#1
Jakes-66-K10 Registered User Join Date: Aug 2004 Location: Idaho Posts: 640	Symptoms of a bad tach? How do you know if you have a bad tach? I scored one from a junkyard the other day (along with lots of other cool finds) and this weekend hooked up everything. This tach kinda works. It "peaks" but won't drop back down. For instance, At first it peaked at idle, I'd rev up the engine and the needle would climb but wouldn't come down. So it sticks wherever the highest RPM setting was. I wouldn't be suprised if I hooked things up wrong though. The distributor hookup and the tach hookup I'm pretty sure I got right but I may have hooked power up to the wrong spot in the fuse box. I'll have to check when I get home... would this cause a symptom like this?

06-13-2005, 05:29 PM	#3
jtminton II Timothy 4:2 Join Date: Mar 2005 Location: Fort Worth Posts: 361	Mine seems to stick at zero on acceleration, then jump over and read really high. __________________ 72 C-20 2WD LWB Custom Camper Deluxe 350 4 Speed "Project Lazarus" MY TRUE PRIDE AND JOY "Dangit, Bobby, people will see that oil stain and think I'm a drunk."

06-13-2005, 06:16 PM	#4
too much stuff Roadtrip! Join Date: Feb 2003 Location: Grand Rapids MN Posts: 13,799	I had 2 of them do that, but they seemed to loosen up with more use. I think they get sticky if they sit for awhile. I think if you hooked it up wrong, it wouldn't work at all. __________________ 67 gmc custom lwb dakota truck. Sold...And bought back 69 swb 4x4 project (in progress) 70 c-10 lwb texas truck 70 4x4/BB/bkts/posi/tach(retired) 70 swb (wifes) 70 jimmy camper 71 K-5 factory 2wd 71 cheyenne 4x4/tach/posi/ plow rig 71 Cheyenne20 BB, buckets, tach, tilt, 4 speed 72 jimmy CST wyoming rig 72 jimmy Colorado rig 72 lifted texas 4x4 3/4 ton burb 65 fury conv. 383/auto 65 chrysler 300 "L" 413 auto

06-13-2005, 04:59 PM	#2
Jakes-66-K10 Registered User Join Date: Aug 2004 Location: Idaho Posts: 640	Bump. No one has seen a problem like this?

06-13-2005, 08:39 PM	#5
Jakes-66-K10 Registered User Join Date: Aug 2004 Location: Idaho Posts: 640	OK. Just to make sure, where do you plug it in at the fuse box?



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.