Tachometer (Aftermarket): Troubleshooting

[bm3w]

Hi everyone,

I attempted to install a cheap (20$) aftermarket tach into my '99 Honda Civic SE (Canadian base model), but I couldn't get the damned thing to work!

I hooked up all four wires running out from behind the tach (ie. tach signal, power, lights and ground), but all that would happen when I'd start up the car is the RPM's would quickly jump to the max rpm on my tach (8000rpm), and then go back to 0 (zero) rpm.. and stay there! The only time it would jump slightly would be if you turn on the A/C, or anything else that required power (ie. press and lift your foot of the brakes). Other than that, the tach would show no response if you gave it gas, in or out of gear.

I'm pretty sure I connected the ground properly (found a screw that was in direct contact with metal), the lights were OK (those on the tach would turn on when I'd turn the car lights on), and I tested the switched power as well (I took a 12V computer fan, grounded one wire, and touched the other wire to my power hookup inside the cluster -- the fan worked no problem).

That leaves me to think that the problem is with the tach signal pickup. I understand that *most* Honda's have a blue wire already leading to the cluster, as these gauge clusters are Plug and Play and can be switched between similar models. I actually found two blue wires, tried connecting to both, but still no luck.

Any ideas?

My next step might be to make sure the blue wires are actually hooked up to the ignition coil or distributor assembly (altough I'm not too familiar with where they should lead).

Any suggestions would be great! Thanks,

Matt

-------(other info)-----
1999 Honda Civic SE 4Dr
D16Y7 5pd stock

[94hondaacc]

Connect The Wire Directly To Your Ignition Coil, Why Would You Even Mess With The Dash? If Your Stock Rpm Is Reading Correctly Then Their No Problem Eith The Wire That Goes To It, Connect The Wire For The Light To Go On To A Fuse Or To The Wire That The Dimmer Works With But For The Rpm Signal Go Directly To The Source.

[bm3w]

Why would I mess with the dash? Because I have been lead to learn that Honda was nice enough to make a blue wire that goes from the ignition coil to the gauge cluster, which is about 2 inches away from where I'm installing my tach. I found it to be a convenient way of doing things, but the results were rather inconvenient =/

[60hz163.5db]

the tach source you found at the dash might not be stong enough. I'm not sure If this is the same wire but a blue wire in a two pin plug on the driverside under the hood. It's towards the front of the car not hard to find.. Or possibly you got a bunk tach...

[SilverY2KCivic]

Of course it's strong enough, it the stock tach that in EX/Si models wouldn't work if that dash tach wire wasn't strong enough.

[bm3w]

Heya Silver,

Any idea why it's not working?

Does it make sense that the power works (because of the RPM spinup), and that somehow the tach signal isn't being transmitted?

[SilverY2KCivic]

Originally Posted by bm3w

Heya Silver,

Any idea why it's not working?

Does it make sense that the power works (because of the RPM spinup), and that somehow the tach signal isn't being transmitted?

It is weird. I emailed you back on the matter, so check that first. It's either a tach signal issue, or possibly a grounding issue. Check the ground connection first thing I'd say, then move onto checking out the tach signal.

[bm3w]

Silver: Thanks for the email. I did indeed try the blue wire on the left of the cluster.

As for the ground, I can try grounding the tach somewhere else.

One other idea popped in my head; the wire I'm using to 'power' (or not) my tach is a YELLOW wire (one of many actually) that originates from Fuse 25 (METER fuse) and leads to the gauge cluster. To tell you the truth, I don't know what the meter fuse is used for...!

All I know is that I have read that in prev. gen. civics, that yellow wire was used as source for "switched power". I did after all test out the power with a 12V computer fan, and once the ignition was fired up, the fan ran as it should.

Sorry to keep the topic dragging on... but I'm dying to get the tach to work! :grin:

Matt

[SilverY2KCivic]

It's all good, and that's what we're her for, to help you out.

What I did with my red power wire was I put a female blade connector onto it, and attached it to a blank blade terminal at the top of the under dash fuse box. This terminal is HOT when the key is in the "ON" (ignition)position, but not when the "ACC" position is on. Use an automotive test light and probe around the blank terminals till you find the correct one. In fact I just looked to see where it's at, and it's the terminal that's on the RIGHT side of the fuse tweezer space between that space and a harness. There will be 3 or 4 other terminals on the left side of the tweezers that may or may not be used depending on what model Civic you have. But you want to tap into the blank blade terminal on the RIGHT side of the fuse tweezers. Hope that helps you out some.