: V8-6-4 dissabling problem... Please, HELP

08-19-10, 02:33 AM
Hi there...

I have been reading a lot about v8-6-4 on this forum, and I finally decided to buy one...

I found a 1981 Fleetwood Brougham, black with dark red velvet interior... I just love it. 70000 km, (43000 miles), one owner, mint condition, but hasn't run for 12 years...

While working on it to put it back on the road, I noticed that instead of dissabling the variable displacement system as it should be done, they just took of the solenoids assembly without doing anything else...

So now, while I'm driving, the car tries to cut of cylinders, but of course it can, so it almost stall, until I force it to get back to 8 (push on the gas)... then of course it runs on all 8, but with a 25 trouble code (variable dispacement failure) and no cruise control, bad gas mileage, and black smoke...

I figured that disconnecting the trasmission orange wire would do the trick since it wouldn't try to go on 6 or 4...

but I can't find the damn wire... My mechanics told me that the black and white wire would do the same thing, so I cut it, and now I got a code 60 (transmission not in drive) and it still tries to go on 6 or 4... what can I do... please, help.

08-19-10, 05:07 AM

one wire at transmission is for kickdown solenoid and the other for 3rd gear switch :) cut the right one and you disabled V8-6-4 (dont know what one it is now)

why not trying to make v8-6-4 working?

08-19-10, 09:11 AM
ok, I didn't know that... so I'll reconnect the one I disconnected, and try to find the other one.

I actually plan on making the v8-6-4 work, but I need to buy all the parts for it since they took everything off.
I just miss two bolts now, then I'll reinstall the whole thing, but I still want to be able to choose when I actually want it
to work or not. (I live in the mountain, and it would just go from 8 to 4 and back to 8 every 10 seconds...)

08-19-10, 09:14 AM
but do both wire go to the ECM? if so, what would it be named?

08-19-10, 09:57 AM
If and when you find the wire that controls the V8-6-4, you can wire in a toggle switch, which will enable you to manually switch from 8-4 and avoid 6.

08-19-10, 02:37 PM
Orange wire, from the trans, driver's side. I'll shoot you a pic next time I am under my car. That might be today ;)

08-20-10, 01:50 AM
so it actually is under the car... but where does it go?

08-20-10, 02:55 AM
it comes out of the ecm, goes to the firewall (the connector at the middle of your car behind your engine) and from there it goes to drivers side to the transmission - there is only one 2-wire connector at the transmission.. one of these wires is the 3rd gear switch (orange wire).

cut it and v8-6-4 is disabled (you can cut the right cable near ecm too.. i can have a look which wire it is so you can put a switch between for enable-disable

i did it this way, because my 3rd gear is bad and so i directly go to ground with the switch

3rd gear switch (the wire you search) gives ground when trans is in 3rd gear - this indicates that v8-6-4 could be activatet --> no ground no activation :)

08-20-10, 04:05 AM
damn, I can't seem to find this wire on the diagram... I have one that goes from the ADL switch (is it on the tranny?) with a black and white and a orange... but the orange doesn't go the the ECM... or I'm blind.

anyways, if you can tell me which one it is at the ECM, I'll trust you...

08-20-10, 12:01 PM
Just get under the car. The orange wire is very easy to see at the trans.

08-21-10, 10:21 AM
at the ecm lower connector (right side the lower one) the wire face to the firewall on top of the connector (black-green wire) is the 3rd-gear-switch cable.. put it to ground and v8-6-4 is running... cut it and put a switch between and you can handle it yourself...

i have ground all time and v8-6-4 is running v8-4 (no 6) above 50 kmph and v8-6-4 above 75 kmph (all)

08-25-10, 04:38 AM
so, yesterday I went on with my V8-6-4 temporary disconnecting, and found the right wire, the black and green, #24 on the third plug... guess what... it works.Thanks a lot. So now I just need to solve the other problems I have and maybe one day the car will be perfect... Next step, discover why I still get a code 33 when I go in high altitude, reinstall the V8-6-4 hardware that was taken off by somebody a long time ago (I still miss a few parts), find out why I don't have a twilight sentinel knob even though I do have the TS signage on the switch and I can here the TS box work when I turn the lights on, find out why when it rains my lights stays stuck on high beams, oh, and hopefully make it pass the emission...pffiou, all that in less than a month...

08-25-10, 05:55 AM
wow great :) in future you can control a relais with your cruise control switch (thats what i'll do next time)
when cruise control is on (a small lamp lights) a relais will get +12V and connects the black/green wire at ECM with ground (and when i get a new 3rd-gear-switch in transmission it will connect to this switch) and thats the way i can use V8-6-4 in 3rd gear (like factory) or can disable it with switch off cruise control switch :)

have fun with solving your problems, ask in this forum if you need help..

09-01-10, 11:24 AM
I don't know about that cruise control switch, I might use one of the switches that was added under my dash...

well, I finally got a look inside that dash... not good... They added so many switches and lights, that it's a total mess... and all the wires are black!!

I was wondering why they took the twilight sentinel lever off... I found out that the TS box was defectif, and it caused a short in the healight harness between the box and the manual switch... so instead of fixing, they juste took the lever off, and blocked the thing on "off".

That's for one thing, I do have parts, so I'm gonna try to fix...

I'll post another thread with my cruise control troubles...

Thanks anyways for your help!