Trip Computer Upgrade, 1995 850 GLT

[mercharch]

I think I've seen this topic covered on other forums, but it never really answered my questions satisfactorily. I was fortunate enough recently to procure a trip computer display and info switch--complete with the display-to-switch wiring harness--with the hope of upgrading my current clock/outside temperature display to the "full bells and whistles" model. Looked to be a pretty straightforward procedure. . .just plug and play. That was until I pulled my instrument cluster this afternoon only to discover the wiring harness on the back of it appears to be incompatible. See pictures below:

As you can see, my cluster does not have the green connector that matches up with the back of the new trip computer, seen below:

Now to my question: Has anyone out there performed a successful upgrade from clock/temp to full trip computer on a 1995 model year 850 GLT [NORMALLY ASPIRATED] with same gray wiring harness shown on the back of my cluster? Is this possible? Is there perhaps a different unit type I should be looking for that matches the wiring harness on my cluster? I am dying to upgrade.

I did come across this image from a thread over at Volvospeed showing the correct green wiring harness on a N/A model; is it as simple as swapping out this little "jumper" harness on my cluster? It looks like it just unplugs from the back of my cluster. Anyone familiar with this item?

This is the type of wiring harness I was HOPING to find on the back of MY instrument cluster. Image borrowed from a poster on the Volvospeed Forums.

IMG_0005.jpg (122.46 KiB) Viewed 5161 times

Any help on this matter would be greatly appreciated--it has been a disappointing couple of days, first learning that my failing ABS control module is a different unit type than those installed in '96 and newer models, and whose DIY repair has been so well documented by Ozark Lee and others. Now this major disappointment. Why do you mock me, 1995!?

::Aaron::

[FCPEURO]

I have never seen this kind of swap done successfully. I have heard people try it many times but they never seem to say if it worked or not. Lee would be your best bet on this one.

[mercharch]

As an addendum to my initial post, I have also considered the possibility of seeking out a new instrument cluster [from a '96 or '97 N/A model, for example] that comes with the desired green harness and just swapping out the whole shebang. That is, provided I am able to find a cluster at reasonable cost. However, I am unsure whether a newer cluster would pair properly with my '95 if they utilized different software or if there is a difference in the way the vehicle computer modules are programmed.

Am I correct in assuming that the green wiring harness was an update for the '96 and '97 model years?

Any thoughts?

::Aaron::

[Ozark Lee]

The '96 and on instrument clusters are different animals. The speed sensor signal is completely different since it was a sine wave signal that comes off of the transaxle on the early models, the later versions had a digital speed signal that comes off of the ABS module.

If I ever get a chance I may try to just insert a diode into the positive side of the sine wave signal and see if the speedometer will work from the old style sensor to the newer cluster. Pulsating DC may be close enough for the speedometer to deal with but the snow is deep and all car related things have been postponed until I have a semi warm and at least dry driveway.

There is also a difference in the ECU, pre-96 N/A versions used the LH-3.2 whereas the '96 and on used the Motronic 4.3 or 4.4. I have both versions of the cars but I have never tried to mix and match the parts. From the schematics I don't think they play well together. The trip computer derives its information from the ECU to give you all of the nifty information on average MPG and real time MPG, etc.

...Lee

[mercharch]

Thank you for the detailed explanation, Lee. . .it is a huge help! At the very least I now know not to waste money on a new cluster. Check.

So with that option off the table, the next logical approach by succession is to determine if there is a way to mate the trip computer with my existing '95 model cluster.

Option A: Find out of it is possible to change out that little gray jumper harness on the back of the cluster and replace it with the aforementioned green harness. . .which might present the same compatibility issues with the ECU if the trip computer I purchased came from a '96 or newer.

Option B: If there is absolutely no way to make it work with my car, I suppose the next best option is to sell said trip computer to someone who can actually enjoy its benefits and set about the [seemingly] arduous task of tracking down a trip computer that is compatible with my N/A '95. . .provided such a thing exists. Does anyone know if the trip computer was available for the N/A '95 850 GLT, and if so, whether the instrument cluster for equipped models utilizes the same instrument cluster as mine, with the smaller gray wiring harness [see photo @ top of thread]?

In case you haven't noticed, I really want to make this happen if at all possible

::Aaron::

[valvster]

When I enquired about fitting trip computer at my local Volvo shop I was told if I supplied the display plus switch I would still need the code to get it working from Volvo which would still cost me about 400 Aussie dollars....lost interest.
Was told the code is individual to each car.

Valvster

[coustyj]

I have a 2007 V50 and EVERY time I put anything eg; fog lights, homeLink, self dimming mirror AND trip computer I MUST spend $150.00 each at the dealer to "activate" said items via the Volvo computer. I can purchase a trip computer made for my car - OEM - made by Volvo for $92.00 it requires a new stalk with new buttons on it. Looks easy enough but still need the &^%$ dealer and HIS computer. The Volvo part number for mine is 31266686 $92.00 from VolvoWholesaleParts.com and $76.81 from MyVolvoParts.com 8685826. The second number is the "old" number (still available!) The 31266686 replaces it. They might have one for your car?????? I miss the trip computer and plan on getting it -. Already installed the fog lights (took 20 minutes ONLY) just waiting for $$$ to go to dealer so they will work. Good Luck
Jim

[ADent]

Did you ever get this fixed?

I picked up a used computer - and it turned out to be for an older car with the grey harness and I need a 9442219 computer that you have shown.

I have the 6849308 and that is good up to chassis 195028 (4DR) with the VDO cluster.

Art - 96 854GLT

[C@lvin]

You'd still need the dealer to enable the trip computer function in the ECU. My 98 did not come with the trip computer function but the clock/temp display in the cluster is trip computer capable and the switch harness is pre-wired in the dash. I can pick up a switch cheap at a pick and pull, but the dealer still wants $250 to enable the function in the ECU. Like everyone else, I'd love to find a way to do this. I have considered finding an ECU at the pick and pull off of another 98 S70 NA car that has the switch in the dash and swapping out the ECU with mine since, presumably, it will have the trip computer function enabled. Anyone ever try that? Any reason not to try that?

[ADent]

You don't need to program the ECU on the older (97-?) cars. There is a guy who had to swap his 95 Yazaki to 95 VDO instrument cluster to get it done - and it works. I guess the cluster could be programmed, but I don't think so.

The earlier cars have 3 separate physically different units - clock only, clock & temp, trip computer (in older (95-) and newer (96-97) styles, and possibly yazaki and VDO versions). So you have to swap out the clock for the clock & temp version for example - the LCD in the clock version is smaller and physically can't show the temp.

Later cars it is just programming.

On your 98 if you swap the ECU and cluster out is there anything else that needs to be reprogrammed to match the ECU?

Art - 96 854GLT