NV Z 28

iTrader: (14)

I am in the process of doing an 4.8 LS swap in my 89 mustang. Has anyone retained the factory gauge cluster? What needs to be done for the oil pressure, speedo, tach, fuel level, coolant temp, and volt meter to all work with an LS engine/harness. I would really like for the car to maintain a factory interior look with the stock cluster. I would hate to have to run all Autometer stuff. Thanks for the help guys!

nuckifuts

iTrader: (7)

Of course. The only big hurdle is the speedo depending on what transmission to use. I would suggest an VSS to cable conversion if i had to do it again.

The fuel gauge is not part of the engine harness so no worries there.

Tach you must use a 4 cylinder tach (at least back when i did my swap 8 or so years ago)

Temp gauge - just use the factory ford sender. I drilled and tapped my water pump housing to screw it in.

Oil pressure. Same as temp. I used the plate on the left rear of the engine.

NV Z 28

iTrader: (14)

Thanks man! I will be running a PSI wiring harness.

How do I do the VSS conversion? I will be running a th400.

Now when you say 4 cylinder tach, I need to get a tach out of a 4 cylinder car?

ls1nova71

iTrader: (4)

You don't need a 4 cylinder tach, just change the tach resolution from 6 to 3 in the tune and it will double the signal to run an 8 cylinder tach.

NV Z 28

iTrader: (14)

Ahh ok. I assume you can do that with HPtuners?

Where should I get a tach signal from? Coil pack?

lsxRanger94

Tach signal comes from pcm wire pin 10(green or red depending on harness). Use a Dakota digital vss with speedo cable hookup. Don't forget to change driven gear in transmission to correct speedo.

Harness info
http://www.lt1swap.com/wiringharness.htm

8k vss
http://www.dakotadigital.com/index.c...rod/prd109.htm

ford to gm speedo cable(midway down the page)
http://www.transmissioncenter.net/sp...n_______va.htm

NV Z 28

iTrader: (14)

Great info. Thanks a lot lsxRanger94!

NV Z 28

iTrader: (14)

So would I be able to put the gear and tire size into HPtuners or would the speedo calculation depend on what gear I have in the trans? How would I hook my Ford cable to the chevy trans?

lsxRanger94

Since you have a th400, the speedo cable would be changed with chevy trans end and a ford speedo end using cable in link shown. use the speedo gears in trans to calibrate speedo. Then you can set hp to correct ratios, but it really only knows the vehicle is moving since the pcm doesn't control the trans anymore. You can wire the PRNDL switch in to let the pcm know you are in park or neutral(there are write ups on here for that). This part of the install is needed to keep the vehicle from lunging when put into gear, but not necessary. There may be a tune in hp tuners repository that closely matches what you have, then you can change it from there.

NV Z 28

iTrader: (14)

Awesome. Thank you for the great info.

streetlegalls1

iTrader: (15)

I used a 4 cyl tack and a raptor shift light,once I leave I've always shifted on a light anyway.Use a bell type oil sender,it's a more true pressure sender,the smaller one is just a switch

NV Z 28

iTrader: (14)

Where could I get one of those senders? Will it work with the factory Mustang cluster and wiring?

lsxRanger94

88 5.0 lx that I had had one.

lsxRanger94

Just remember ford had an issue with the factory guage showing low oil pressure. Their fix was to add a resistor to the back of the cluster. It would then keep the needle in the middle of the normal range if the pressure was above 0 psi. You can remove that resistor and the guage will function like a normal pressure guage. There are write ups on the web about it. So check your cluster to be sure you don't have FORD's fix.

NV Z 28

iTrader: (14)

Thanks man. Will do. I will have to check it out.

lsxRanger94

Some dealer installed fixes had the resistor at the pressure sender wire( a couple of inches up from the sender and are covered in heat shrink.) should be eay to spot. Another way to tell is if the engine you pulled had the bell style sensor or not. If it did not, you will have to look for the resistor. An actual pressure sensor(bell type) without the resistor removed and by passed will show NO oil pressure on the gauge. Just trouble shooting for you before you have to post again after you are done with the swap. I hope this helps. My 88 lx had the damn thing and I put a new sensor in it and had no reading, then I took dash apart and removed Ford's mod. Then I had oil pressure again on the gauge. After letting the car sit for two weeks until I figured that one out.

NV Z 28

iTrader: (14)

Ok cool. Thanks for the info dude!

streetlegalls1

iTrader: (15)

Correct info I failed to mention

NV Z 28

iTrader: (14)

Sorry to bring this back from the dead but I am having trouble getting my stock tach to work. Its a 89 5.0 car. Can someone please elaborate on how to correctly wire the factory fox body tach??

zipster

iTrader: (5)

On the ford harness, there is a tan/yellow stripe wire. this goes to the tach output from the chevy ECM. be sure to tell the tuner to change the tach output from 6 to 3 as said above.