Tachometer Not Working 2001 EXV6
 

With Help from members of this forum I recently replaced the alternator and tensioner pulley on my wifes 2001 Accord EX-V6. When I was taking it for a test drive, I noticed that the tachometer was not working.

When the key is turned on the tachometer needle moves up to the zero mark, so it seems to have power.

There are no other warning lights, and the speedometer is working. I made sure that all of the warning lights are not burned out.

Any suggestions?

Thanks for your help!

I believe the tachometer is controlled by the PCM (engine computer) on your car. Check your work on your alternator for loose connections. Check the battery cables too.

I checked all of the cables and connections. Did many tests with the multimeter for loose grounds. I pulled and checked all fuses. When I did this I think I may have reset the PCM. Now the Tachometer works!

Since the last post, however, there have been blinking lights on the dash at random times. The brake light, battery light, and door lights will all flash at the same time. After doing quite a bit of research, it seems that sometimes aftermarket alternators are not a good fit for hondas. The alternator in question was a new alternator that I bought from Advance Auto Parts (Tough One Alternator.)

I think I may bite the bullet and just purchase a new Delphi from hondapartscheap. Thanks for the help and I will keep you posted.

Before doing that.....re-check the connections at the battery, be sure they are clean and tight. I would also clean the "other end" of the gound cable where it contacts the body and then the trans.

Got a voltmeter?

Don't toss that alternator "just because" it's not genuine. Monitor the car's voltage when it's running, while you turn everything on & off.

Non-genuine alternators aren't BAD, they just seem to have a reputation for shorter lifespan. When they screw up, you should be able to measure something (voltage) that isn't correct.

Jim, Yes I have a voltmeter. I first measured the volts of just the battery. Then measures the volts with the car running. Then I tested the volts with the car running with the stereo, headlights, turn signal, AC all on. This was done at 1500 rpm. The alternator definitely seemed to be working fine.

At random times when driving down the road I will get flashing lights on the dash. There is no pattern to these flashes. The brake light, battery light, and door lights will all flash at the same time. Sometimes just a single flash. Other times multiple flashes.

However, I cannot get the dash lights to flash while I am parked in the driveway, even with all of the lights and AC turned on.

As poorman212 has suggested, I checked all over the car for loose grounds. I have used the volt meeter to do a series of test to see if I can get a reading that proves that there is a loose ground. I have had no luck.

My wife has driven the car for the past week and a half this way, so the alternator seems to be working. The random flashing lights are just a pain in the ass an I would like to fix them.

This car has 180,000 miles on it and has been very reliable and well taken car of. Thanks for the help and suggestions fellas!

Off the deep end.......does the engine "stumble" when the rpm's/tach act up?

Recheck the charging post of the alt to be sure it it tight....but not over tight....the plug for the alt, be sure it is seated all the way.

No, the engine does not stumble when the dash lights are flickering. The car is running great.

It is funny that the dash lights have not flashed in the last two days and my wife has driven all over town. Go Figure.

When I changed the alternator, I did have to crimp on a new terminal on the charging wire that connects to the alternator. I have triple check this connection and it seems tight with no wiggle. Perhaps I should redo this connection.

Thanks for the suggestions!

Well the dash lights kept flickering, so I purchased a Honda Remanufactured alternator from Majestic Honda. The car fired right up and and there are no more flickering lights.

Everything is running fine! Thanks to everyone for their help. If you are ever in Pueblo, CO let me know. I owe you a cold one.

Thanks!
Nathan

Thank you for the follow up.....too many time we never know what the "fix" was.....so thanks again for letting us know.