85 GTV6 Speedo Issues

[bayalfagtv6]

steveh29,
Well, I installed new Milano sender, Milano amp and wired as per instructions, speedo still zero. I know I am getting 12 vdc at the power output at the amp box. The other output at amp shows about the same.... I don't think it should show soo much voltage, what's the next step. Don't know how to check the signal, Run the car on jackstands and see if the signal wire power changes, do you think the sig will fix my problem, need some help here.

Thanks
William

[steveh29]

My first step if I had no speedo activity at all was to make sure the wires from the speedo to the sensor were OK - nothing broken. You could just use a common volt meter to check that. Beyond that, I think you'd have to get a scope to read the signal coming off the speedo sensor as the transmission turned. That's beyond my electronics skillset.

[alfaparticle]

You will not see a pulse from a Milano sender for the reasons that I stated in an earlier post. The sensor has 3 wires. Two of them are connected together in the sensor. You should be able to measure a fairly small resistance between either of those wires and the third one. With everything hooked up and the wheels spinning under power, I think that you should see a pulse train to the speedometer. I also think that you shouild see a voltage on the DC scale of your meter that increases with speed.

[bayalfagtv6]

I am in the midst of checking the wiring from sensor to connector at speedo. The only problem is I only have a wiring diagram for the 83 GTV6 and the one I'm working on is a late 85, 86 model. No wiring diagram in the owners manual like I have for the 83. What wires at the connector (speedo side) are linked to the sender, any clue? One should be power and 1 should be pulse and then a ground...

[steveh29]

I don't have a GTV6 wiring diagram for the instrument panel. I do have one for the Milano although that doesn't help.

[Mark_toro]

I got the stock GTV6 speedometer to work in my car with the Milano transmission. It required the Milano sensor and amp box and the Dakota Digital box.

My GTV6 originally had the gear drive sensor (early 85) The Milano trans has an inductive sensor (87 up). I am not sure, but I think that the late 85 and 86 GTV6 may have had a different type of inductive sensor.

It is a good idea to have the correct sensor for the transmissions that you are using - obviously the gear drive won't work in an inductive trans. Any Milano sensor will work in any Milano trans - don't need to worry about the gear ratio (or tire size) with the Dakota box.

I know that the Milano system would not work w/o the Dakota box to condition the signal. Also, unless you have an ocilliscope, you won't be able to read the signal from the Milano speed sensor.

I will pull my notes on the wiring of these components and try and post them here tomorrow.

Finally, the toothed "wheel" that the speed sensor reads is part of the pinion shaft, so changing a Milano transmission over to use the geared sensor would require swapping in the pinion and crown gear and then setting backlash and pinion depth. Possible, but probably not worth it. I ended up doing this because I wanted the 4:11 final drive and the Verde limited slip.

[bayalfagtv6]

So Mark,
i have a late 85 GTV6 with inductive type sensor and original GTV6 gearbox, inductive type. I have the Milano sensor and am not getting any signal to speedo. Do you think the Milano LSD setup was different enough that the late GTV6 setup won't work at all??
Do I need to change transaxle to LSD to get things to work??

[Mark_toro]

I think that this write up will help you in you situation. I think I picked it up from ALFAGTV6.com. Notice that there are two different inductive senders one for the late GTV6 w/o amp and one for the Milano w/ amp.

So if you are putting the Milano sensor into the late GTV6 box with the late GTV6 speedometer it apears to work if you also include the amp. Because I was converting from an early GTV6 with gear drive sensor, I also had to include the Dakota Digita box to make it work. The speedometer internals are different between the early GTV6 and the Milano - sounds like the late GTV6 speedometer is similar to the Milano.

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Making the 1986 GTV6 Speedometer work
I bought my 1986 GTV6 in 1999 with non-working Speedometer. Now finally in 2003, I have gotten the original 86 GTV6 Veglia speedometer to work in this car. First off I had Palo Alto Speedometer, Inc. at Palo Alto Speedometer: Repair, Restoration, and Sales of Automobile Gauges test speedometer and repair circuit board.

This 86 speedometer p/n 60701830 (original p/n 113.1064.014.03) is different from the earlier GTV6 in that it has 4 wires instead of three coming out of head This fourth wire is green and mounts to a separate terminal added to exterior of housing and is not part of red 6-pin connector. It also uses a 3-wire Jaeger hall-effect sender instead of a 2-wire Veglia rotary sender.

This added on 1-pin connecter (green wire) for 86 GTV6 is for signal from 3-wire Jaeger Hall-Effect type sender via pink-black wire.
Note: This sealed sender unit senses gear tooth movement in transmission instead of being a rotary actuator sender like earlier GTV6 and the 164.

The 6-pin red connector that connects to speedo housing has the following 3 wires for speedometer circuit:
6 – Pink 12v wire is input power wire to speedo red wire and housing back lighting/indicators
5 – White-red is output signal wire from speedo yellow wire to sender in transmission
2 – Black is ground to sender

My car’s problem was original 3-wire Jaeger sender would not send a signal to speedo. It didn’t have an amplifier like the Milano. So I removed the 86 GTV6 sending unit and replaced it with Milano sender and amplifier. Now speedo works and is accurate.

86 GTV6 sender wire colors are as follows:
Black – ground to black ground chassis wire
Grey – power input to sender from white-red wire in chassis harness
Pink-black – signal from sender via pink-black chassis wire back to green wire on speedo

Part number info:
Milano speedo amp 60529121, 3-wire Jaeger w/Bosch connector
Milano sender 60529120, 3-wire Jaeger w/Bosch connecter
86 GTV6 sender 60526262, 3-wire Jaeger non-amplified

I also used Milano 3- wire chassis harness and connector to hook amp wiring to GTV6 harness.
Here is color-coding of wiring and how I connected them together under rear seat:
GTV6> Milano> AmpI/O Amp> Sender Function

Red-white, gray, white, white; brown power in
Pink-blk, pink-blk, red, red; yellow signal out
Black, black, copper, copper; copper ground

[Mark_toro]

For those with an early GTV6 who have swapped in a Milano transaxle, sender and amp. Here is what I had in my notes regarding the connection to the Dakota SGI-5 (revision C) box.

the 12 V accessory power terminal was connected to the Red lead that comes from the chassis harness. This lead is 12V+ when the ignition switch is turned to "on". The pink wire that goes to the amp was also connected to this 12V+ source.

The ground terminal was connected to the chassis with a sheetemtal screw.

The bare ground from the amp was connected to the sensor ground terminal.

The Green wire from the amp was connected to the speed signal terminal.

The Red/White wire form the amp was connected to the calibrated AC output signal terminal.

It took me a while to get the right dip switch settings. I don't have the car with me today or I would pull the rear seat cushion and double check. The picture I have is not very clear, but looks to be:
#1 - off
#2 - off
#3 - off
#4 - on

Try this for a start - you can't hurt anything with the switch settings.

Once I got the spedometer to register something consistantly, I adjusted the setting by driving past one of those radar "your speed is" signs. The spedo has been working fine for three years now.