Need help with factory tach

[DarkProphet]

hey guys I'm having a real problem with my factory tach. Sometimes it works fine, but others it will say im idleing around 100 rpm's and wont really move much. Once i hit around 4k rpm's (a guess.... cuz the tachs not working) the tach will go up to around 6k VERY fast. Anyone know of any reason why it would do this?

 

[Willicuddy]

hey guys I'm having a real problem with my factory tach. Sometimes it works fine, but others it will say im idleing around 100 rpm's and wont really move much. Once i hit around 4k rpm's (a guess.... cuz the tachs not working) the tach will go up to around 6k VERY fast. Anyone know of any reason why it would do this?

Was looking for a post that described my problem exaclty. Anyone know of a fix? I have a monster tach and it reads fine, but the stock one has the same issues described above.

 

[The Green GT]

Bad wire?

Its tan with a yellow stripe.

 

[Willicuddy]

Im thinking that might be the case. The tards that installed the Monster tach, spliced it right at the Coil, and when i went to try and disconnect it The female connector (one with the tan wire) came right out of the plastic connection. I tried to put it back in, but I guess the connector is shot.

You guys think I can repair it because Ford dealerships in my area don't carry the part anymore and most wreckers won't sell me it because I ruins their motorsets. Or does anyone know of a place that would sell an aftermarket one?

 

[The Green GT]

Im thinking that might be the case. The tards that installed the Monster tach, spliced it right at the Coil, and when i went to try and disconnect it The female connector (one with the tan wire) came right out of the plastic connection. I tried to put it back in, but I guess the connector is shot.

You guys think I can repair it because Ford dealerships in my area don't carry the part anymore and most wreckers won't sell me it because I ruins their motorsets. Or does anyone know of a place that would sell an aftermarket one?

Im not sure but I spliced my shift light into the wire behind the cluster, you can do the same with the tach.

 

[Willicuddy]

Yeah you can splice everything for the tach/shift light at the cluster. My issue is that when they spliced it at the coil the ruined the connector, which has the brown/tan wire in it.

I guess I will try radio shack maybe, and make a new connector or something.

 

[Synned]

Funny this thread is here...my tach just started acting up.
It will jump from like 4-45 and then stick and then jump again...but I don't FEEL that.
So this tan/yellow wire runs from the back of the tach directly to the coil?

 

[Willicuddy]

Yeah, from the right side connector on the back of the instrument cluster all the way to the coil (a brown plastic 2 prong connector)

 

[urban96]

if you buy one of those MSD no cut connectors to use with one of their ignition boxes it comes with a new plastic connector that plugs into the coil.

http://store.summitracing.com/partdetail.asp?part=MSD-8874

 

[Synned]

Aight guys, someone explain this to me:
How is it possible that a tach would only fluctuate REALLY BAD when flooring it in 3rd gear? It doesn't make sense.