tachometer/temp gauge wiring

[natmanjoh]

Tachometer and temp gauges are not reading anything after engine swap. Thinking I wired wrong. Been trying to compare the two diagrams but I suck at wiring diagrams. Where do these wires run so I can check them? 89 2.9 to 94 explorer 4.0 swap was done. Thanks for any help.

 

[RonD]

Look here for the tach wiring
http://www.therangerstation.com/tech_library/Tachwiring.html

 

[natmanjoh]

Already looked at those and compared wire diagrams in my Chilton for 94 Exp and 89 b2. I found the yellow/tan wire at the pcm (tach wire according to diagram for 94 Exp) and its suppose to go to slot 4 but there is a blue wire in slot 4 at the firewall. I don't know where the yellow/tan wire went as it is in the wrapped wire harness. I don't see a blue wire on the b2 wire diagram for the tach. Am I missing something? Don't see any other wires to check in the diagram. Any other wires I should check besides trying to find the yellow/tan one? Haven't started the temp one yet as I will probably just use an after market one but I want everything hooked up if I can.

 

[RonD]

On the 1989 2.9l you would have had a distributor and coil, the tach wire would have been green coming from the "-" on the coil, and run directly to the tach in the dash board

The 1994 4.0l would get the tach signal from the Crank Position(CKP) Sensor via the PCM.
That's the tan wire, so that is the tach output wire, it would run direct to the tach on the '94 dash.
I don't see a connector diagram for the 1989 instrument cluster, so you may need to find one that IDs the tach wire at the dash board, thats where the tan wire would connect.

Same for the temp gauge, the sender on the engine is just a resistor, so 1 wire from that to the dash board gauge.
So you need that connector diagram, for the 1989 dash board

 

[SenorNoob]

IDK where you're trying to make your connections at, but; Ford changed wire colors inside the harness several times. (Always as the wire goes through a connector.)

Like this:
------------
Tan/Yellow Wire----| Connector | ---- Dark Green/Yellow Wire
------------

BTW, that's the tach wiring in my case (92 Explorer harness). I wouldn't be surprised if Ford did them all that way. Oddly enough, the point that I used to make the connections had (just a few inches form the "Big White Plug") all the same wire colors as my 88 Ranger on the connectors in that area that carried the dash signals.

Only way to be sure a wire is going where you think it is is to follow it from one end to the other. But, a resistance test on a voltmeter is usually acceptable.

 

[adsm08]

No Ron, the 2.9 tach works the same way as the 4.0 tach, but on a slightly different signal form.

The green wire you reference feeds a signal to the computer, and then the computer feeds the tach a duty-cycle ground to set the needle position.

In the 4.0 setup the computer takes a signal off the crank sensor and then uses the same duty-cycle ground setup to set the tach needle.

IIRC the tan-yellow wire coming out of the computer gets kinda bruised and turns black and blue at the fire wall. I am pretty sure that is how my truck is set up, with it black and blue at the cluster, tan and yellow at the computer, however my tach only reads to about 2000 RPM.

The 90 4.0 diagrams I have show the power side of the tach taking a signal from the EDIS module and running off to ground.

 

[RonD]

OK.

I was basing it on this diagram
http://www.therangerstation.com/tech_library/EDiagrams/files/Diagram_Ignitionsystem_1989_2_9.JPG

Green wire off the "-" and "to tachometer", DG/Y wire

 

[adsm08]

Yeah, I know what the diagrams say, but sometimes you get into the wiring and find things don't match quite right.

I am going off what I found when I actually tore things apart. The 2.9 might actually run off the coil ground. I know it did on some earlier years. I also know that the later tachs get their signal from the computer, which is what he needs to be worried about if he is using 94 wiring.

I have a 94 engine harness, an 89 dash harness, and an 87 dash. His setup is pretty close to the one that I have almost working. I don't have a temp gauge yet either.

 

[RonD]

You mean actual wiring might very "slightly" from the factory wiring diagram????

"Say it ain't so Joe", lol

 

[adsm08]

You mean actual wiring might very "slightly" from the factory wiring diagram????

"Say it ain't so Joe", lol

Depends on how long I have owned it.

My BII matches the books pretty well.

I have 4 different factory wiring books and a college ruled noted book of my own hand-drawn diagrams and written notes, all of which I need to do electrical work on my truck.

Even the Escape isn't stock. I swapped two pins at the GEM so it releases the lift gate and not the glass when I hit the button on the remote.

 

[natmanjoh]

So I'm assuming I should just tear harness up and follow wires to see where the connection has gone bad. First vehicle I've worked on so wiring has me confused. Truck runs and is auto so tach doesn't matter. But I want to do a 5 speed swap so I need tach. It is the 94 wiring harness from exp. Oh, side note, probably something simple, trying to take gauge cluster off dash and got the panel off, bolts holding cluster but it keeps getting snagged on something. Assuming its the wires in the back, but I can't pull it far enough forward to stick my hand back there and feel what's snagging it. Any ideas?

 

[RedRyder97]

Cluster Swap . No Tach Cluster to a Clustered Tach Question

I have just pulled this old 97 2.5 5 speed out of the back woods . time for my son to drive but hes haven a problem hear when to shift and my self I would like to have a Tach in it to . I dont really know why ford didn't put a Tach in the 4 bangers with 5 speeds.

So Can I pull a dash cluster out of a 95-96-97-98 and just install it in my 97 that does not have a tach ?? A year ago or more I was going to install a External Tach but never did .Someone said why not swap the gauge clusters . Anyone have info on this ?

Thanks Guys .

 

[adsm08]

So I'm assuming I should just tear harness up and follow wires to see where the connection has gone bad. First vehicle I've worked on so wiring has me confused. Truck runs and is auto so tach doesn't matter. But I want to do a 5 speed swap so I need tach. It is the 94 wiring harness from exp. Oh, side note, probably something simple, trying to take gauge cluster off dash and got the panel off, bolts holding cluster but it keeps getting snagged on something. Assuming its the wires in the back, but I can't pull it far enough forward to stick my hand back there and feel what's snagging it. Any ideas?

You don't NEED a tach to drive stick. You need skill to drive stick. I had been driving a manual for 5 years before I had my first tach.

And you are probably getting stuck on the speedo cable. Reach your hand up the back from beneath, find the collar on it, squeeze and pull.

I have just pulled this old 97 2.5 5 speed out of the back woods . time for my son to drive but hes haven a problem hear when to shift and my self I would like to have a Tach in it to . I dont really know why ford didn't put a Tach in the 4 bangers with 5 speeds.

So Can I pull a dash cluster out of a 95-96-97-98 and just install it in my 97 that does not have a tach ?? A year ago or more I was going to install a External Tach but never did .Someone said why not swap the gauge clusters . Anyone have info on this ?

Thanks Guys .

Not really sure how this doesn't warrant it's own thread, rather than a post in someone else's thread about a totally different problem and vehicle, but sure.

Yes, you can grab a cluster from the same style dash and pop it in your truck. The wiring is already there.

 

[zekew64]

Adam, a question:

You said that you can swap clusters if they are from the same style of dashes. Does that apply to 89-94 clusters as well?

(Note: Apologies. I know this is an old thread, but I still felt I needed to ask the question.)