I posted this before but I've made some significant updates that I didn't have time to do before. Most who know me, know that I have a knack for picking DIY projects that somehow become much more difficult than I expect... This was when I had my 99 TL and a warm up project to my Nav retrofit... (which was much easier in fact, just more time consuming...)


Original idea:
Purchase Type S instrument cluster.
Basically plug and play with 2 known issues

1. D4 would skip over to D5 (according to the service manual)
2. VSA would light up continuously and TCS was covered up (bulb positions were different)

Unfortunate and unexpected issues after initial test install...
- Mileage not corrected (showing 16k instead of 72k)
- Heat gauge goes above H after 30 seconds
(thought it was a faulty heat gauge, turns out the Type S guage is not compatible with the TL-P signal)

Great idea... turned out not so great...
Since I wanted to retain the mileage and have the white gauges and eat my cake too... I thought I would keep the original 99 TL-P circuit board (which housed the mileage chip) and just swap out the guages and figure out how to align the gear display (D4 / D5). I figured swapping the Type S brighter LCD would be pretty easy...


Here is the Type S cluster disassembled. The white pieces sandwich the circuit board


Swapped the gauges around in hopes that they would just plug and play...

The gear display alignment was the easy part... after swaping the gauges, neither the fuel worked (no movement at all) nor the Heat gauge (shot up to past H immediately). I then discover that the TL-S Fuel and Heat gauges have different pinouts / orientation on the circuit board... not to mention that the LCD screen pins were soldered directly on the circuit board which made the LCD swap a challenge.

Solutions

LCD
The LCD screen was the "no turning back" mod. I took a small pair of pliers and clipped all 30 pins on my original TL-P cluster board. Then I proceeded to clip all 30 of the TL-S pins. The Type S LCD pins were cut longer and the the TL-P circuit board pins cut longer so that the two would overlap and be easier to solder.



The Philips screws were solder filled and required desoldering. I put the Type S screen in the TL-P board and re-soldered all 30 pins and just prayed that it would light up properly which, thank god it did...



Gear Display
This was an easy trick... The little bulbs on the circuit board are housed with rubber on the bottom. I used the TL-S housing which had 1-D5 spaces and I simply spread the N and the D4 bulbs apart and placed the housing over top, forcing the bulbs in the right slots and leaving the D5 cavity without a bulb. Only issue is that the one of the clips in the rear will not close 100% upon re-assembly (I can live with that)


Fuel and Heat gauges
These were by far the most difficult to correct. The gauge pins go through the circuit board, flower out in the rear (rivet style) over a round circuit connection point and is soldered on.


I had already corrected the Fuel pins but you'll notice that the Temp pins are still different.

To correct the pinouts, I had to desolder and remove all 6 pins (3 each), use a knife and dig up the round contact in the rear and remove them all.



Then I reinstalled all the pins which now do not connect to anything. They are now a bit wobbly but work just fine.

To figure out which pins were what, I had to trace the circuit board until I knew basically if it was ground or some sort of signal. I then took both bare boards and hooked them up to the car, used a volt meter to confirm 100% what the pins were. I found 1 x ground, 1 x 12volt (ignition), and one negative signal (bingo!). I wrote the -ve numbers down and tried the other board... (bingo!) correct signals located.

The fuel gauge from the TL-P and TL-S are actually different and the TL-P gauge did not have a proper ground but since I knew the correct signal wire, I just ignored the odd connector and patched a ground in to bring it back to life.

I mapped everything out and soldered trace wires in the rear to correct the pin layout.



After all the wires were done, I put the assembly (bare bones) back together to test

Bare bones testing. Notice the nice bright LCD display.

and to only realize that the signal on the temp sensor was much higher than normal, i.e. when the car was cold, it showed about 1/8 temp and when the car was warmed up, it was almost past the H. I realized that the only solution was to adjust the signal (which was resistance) of the TL-P to match the Type S temp guage.

I tested the resistance of both the Type S and TL-P temp signal and found an approx. 180ohms difference. I went out to Fry's and purchased a 250ohm trimmer which is a mini potentiometer (POT) that will adjust from 0 - 250 ohms of resistance. This allowed me to literally calibrate the temp needle by simply turning the trimmer with a small screw driver.


Had to bypass and reroute the temp signal to the trimmer


Trimmer connected. It's the little blue square attached to the black wires.


Another shot of the trimmer. Wires attached to the bottom.


Had to be careful reinstalling the housing.


Assembled with trimmer exposed for fine tuning. (small blue square)


TCS / VSA
Finally to correct the TCS / VSA location issue, I severed the VSA connection on the circuit board with an Xacto knife and simply soldered a trace wire from the TCS over to the VSA bulb connector. So now the VSA acts as my TCS light.



Cluster assembled and reinstalled.


Fully installed. This is the temp right before the fan kicks in and brings the temp back down.

Awesome!
hah looks like a tough project, nice outcome though
good persistence

You definelty did your homework before attempting that one.

Good Work

holy shit :hail:

lithiumus did my custom short shifter... show them that one, Garrick... lol

Originally Posted by Ian Carlo

lithiumus did my custom short shifter... show them that one, Garrick... lol

Alright... here it is... I've still got picks and write ups for 4 more projects... some are still incomplete and some have been shelved forever after I got my new car....

http://forums.vitalmotion.net/viewto...=245712#245712