TACH - PROBLEMS please help!

[scot w.]

I just got done installing my tach and it DON'T work. the lights work, it's got power to it, when i turn the ign on the needle goes to 0 and then to 1 and after starting the car it don't do anything. the needle only moves when i move the SHIFT-SET dial. I double and triple checked all my connections. how would i check the two tach wires in the engine bay to see if it's sending the correct voltage to the tach? and if they are no good what wire would i tap into coming from the ecm? the only thing it's NOT doing is getting the info from the tach connector. thanks, scot w.

 

[Raymond Bunch]

Hi Scott, just wondering which tach you went with? If it the 5" Autometer one I think you might have went with, you will have to snip one of the wires in back of the tach to make it compatible to run with a V6. Should say in the instruction if your tack is new. Other than that if everything is grounded properly and has the right power source, I dunno

 

[scot w.]

Yes, the brown wire was snipped. I failed to mention it before i'm sorry. I'M AT A LOSS HERE.......

 

[Raymond Bunch]

If I remember right there should only be one wire in the engine bay by the ALT. that the tach wire plugs into, not two. By any chance, did you plug it in the fuel pump wire also down by the alternator? I got them mixed up once :redface:

 

[pacecarta]

I double and triple checked all my connections. how would i check the two tach wires in the engine bay to see if it's sending the correct voltage to the tach? and if they are no good what wire would i tap into coming from the ecm? the only thing it's NOT doing is getting the info from the tach connector. thanks, scot w.

what two tach wires ????

there's two connectors behind the alternator ,
one is the prime feed for the fuel pump (has a female spade on the end) the other is the tach (male spade on the end)

 

[scot w.]

Yes, the tach wire behind the alternator HAS two wires going to a male spade connector.(green) and that is where it's pluged into.. back to the MAIN question: what is the correct voltage reading at that tach wire? and second, how is it checked with a multi-meter? and where is the best place for the ground for these tach's? thanks, scot w.

 

[scot w.]

Ttt

 

[scot w.]

answer?

Out off all these people on here know one knows this answer?

 

[Raymond Bunch]

Out off all these people on here know one knows this answer?

Sorry Scott I tried, I even did a search and could find nothing. Hopefully some of the more experienced fellas will chime in. Come on guys, any Ideas? Now I need to know too, I'm stumped

 

[pacecarta]

sometimes people go to sleep and sometimes they go to work
im not one of them but still

the tach output is 5V squarewave and shouldnt be tested with a multimeter , a scope or a tach is the only way to test

 

[machinegun]

Do you have a analog dash TR and if so does your stock tach work?

 

[scot w.]

Do you have a analog dash TR and if so does your stock tach work?

No, digital dash. and a scanmaster and the rpms work on the scanmaster. What i'm needing to know is how to find out if my tach WIRE with the (green) connector is any good. and if it's not WHAT WIRE or WIRES coming from the ecm can i use????

 

[scot w.]

Any info on how to test the tach wire? or which wire or wires would I go to coming out of the ecm?

 

[scot w.]

Ttt

 

[Lee Thompson]

Ain't this a bitch?

You could probably get more help if you would reveal what brand tack and what type ignition system you are dealing with as I had a like problem this summer and may be able to answer your ?

 

[scot w.]

YES, a total pain in the a**

You could probably get more help if you would reveal what brand tack and what type ignition system you are dealing with as I had a like problem this summer and may be able to answer your ?

Well it is a 5" autometer (autogauge) part# 233905. I have checked everything over and over. got the red wire hooked to the (ign) on the fuse box 12v, got the white wire going to the lights for all my gauges, green going to the tach wire behind the alt w/ green connector, black wire is connected to all my other grounds at the bottom of the dash. (good solid metal ground). and I've even moved the ground to the engine, still nothing......

 

[puddinpower]

You could probably get more help if you would reveal what brand tack and what type ignition system you are dealing with as I had a like problem this summer and may be able to answer your ?

Lee, it is a stock ignition system. I think the tach is bad, but I have been wrong before! Which wire comming out of the Ecm or modual has a tach signal? I am at work and donot have my manuals here.

 

[Rodney87GN]

The white wire from the ign module is the tach signal for the analog cars. I think it's pin D or E. If you can find a way to tap directly off this pin you'll eliminate the green spade connector and its wiring as suspect.

If it still doesnt work your tach,or even ign mod could be bad.

Also check the easy junk like fuses...whatever ign power source you plugged the tach into.

 

[Lee Thompson]

No help

I had trouble with a VDO tach. It doesn't seem to be compatable with a type II ignition module. Sorry. I can not check now, but I do believe my Cyberdene tach is tapped into D-4 @ the ECM

 

[Lee Thompson]

Jolly 460 is right

I do know the white wire behind the speedo is the tach lead.