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the button disables 4th/OD when the light is lit, this leaves you in 3rd gear, which may be more suitable for going up/down mountain roads, towing, etc.
Okay so to state this correctly then what's not working on my car right now, after doing the work on it, is the ability to click the gear shifter OD button and disable 4th gear. The disabling of 4th gear and the dash light indicator are no longer working.
The little kick I was describing, when the OD button previously worked, was now quite obviously the car dropping to 3rd gear.
Originally Posted by pierce
4th gear *IS* overdrive.
the button disables 4th/OD when the light is lit, this leaves you in 3rd gear, which may be more suitable for going up/down mountain roads, towing, etc.
Last edited by volvodriver99; Feb 13, 2020 at 05:40 PM.
ok, pull that 3-pin connector in your picture above, the one with the 2 grey and one white wire. connect an ohm meter between the two grey wires, push the button on the shifter, it should be 0 ohms, release the button it should be open circuit. that verifies the button circuit is working.
hey, its also possible the dashboard light is misconnected or disconnected.
another test, pull the relay, find that paperclip, and connect pin 15 (power) to 87a, with the ignition on, the OD light should stay out. now connect pin 31 (ground) to 87a, the OD light should come on.
All below tests were done with the car running and in drive.
The multimeter test on the 3-pin connector with the 2 grey wires and one white wire is indeed showing 0 ohms when the shifter button is pushed and open circuit when the button is released. So this means the O/D button on the gear shifter is working.
As far as pulling the relay to do the light bulb test with the paperclip as a jumper the results are slightly different than you stated.
15 with 87a does nothing.
31 with 87a does nothing.
86 with 87a turns the dashboard O/D light on.
87 with 87a turns the dashboard O/D light on.
Originally Posted by pierce
ok, pull that 3-pin connector in your picture above, the one with the 2 grey and one white wire. connect an ohm meter between the two grey wires, push the button on the shifter, it should be 0 ohms, release the button it should be open circuit. that verifies the button circuit is working.
hey, its also possible the dashboard light is misconnected or disconnected.
another test, pull the relay, find that paperclip, and connect pin 15 (power) to 87a, with the ignition on, the OD light should stay out. now connect pin 31 (ground) to 87a, the OD light should come on.
huh, cuz 87 and 87a are wired directly together in the relay.
oooh, 87 goes to the solenoid, which goes to ground, so yeah, that would light the light (the solenoid is only a few ohms, so the light might be dimmer than normal, but still light)....
this suggests that maybe 31 isn't grounded ? can you check continuity from the OD relay's socket pin 31 to chassis ground ?
Testing 31 of the socket with one wire from my multimeter and the other wire on my multimeter going to the car ground yields nothing on the multimeter.
I checked 15, 86, 87 and 87a the same way as well and only 86 and 87 give me a tone on my multimeter. And they only do it when I touch the multimeter to the gold screw, NOT when I do it to the black frame that you see in the picture. Incidentally ground 13 wire is not touching the gold screw directly either since it's in the batch first, it's the one with the red sleeve around it.
Originally Posted by pierce
huh, cuz 87 and 87a are wired directly together in the relay.
oooh, 87 goes to the solenoid, which goes to ground, so yeah, that would light the light (the solenoid is only a few ohms, so the light might be dimmer than normal, but still light)....
this suggests that maybe 31 isn't grounded ? can you check continuity from the OD relay's socket pin 31 to chassis ground ?
the black wire from the relay socket should go straight to the ground screw on the right side of the center console.
the 3 pin connector according to the schematics, BOTH sides should have 2 grays and a white wire. in your picture, it looked like 3 white wires on one side, huh.
I was wrong about the pushbutton, at the relay, one side of the pushbutton is wired to pin 15 (power) and the other side to relay pin 86. relay pin 15 also gets a blue wire from the fuse panel, this goes via a 4 pin connector 'H' that is buried up behind the dash somewhere, and has a blue wire with fuse 11 power, and a yellow-red wire to the dashboard light at pin 34 (a separate spade lug which is right next to the OD light on the dash))
Is there a definite test we can do on the relay when it's pulled to make sure it's not bad as well? I was doing what was in that video I sent yesterday but you had said this relay is more complicated than that.
then your black wire on pin 31 is NOT grounded properly.
the definitive relay test would be to take the relay out of circuit, connect pin 31 to a 12V battery -, connect pin 15 to the battery +, and momentarily jumper 86 to 15, the relay should click each time you do this. for an even more thorough test, connect a test light from 15 (+) to 87a, and another test light from 31 (-) to 87. each time you tap 86 to 15, those lights should toggle (only one would be lit at a time).
Even with 31 now turning the dash light on when jumpered to 87a you still think I'm not grounded properly? To me that would say it is grounded properly.
I'll do the full relay test tomorrow.
Originally Posted by pierce
then your black wire on pin 31 is NOT grounded properly.
the definitive relay test would be to take the relay out of circuit, connect pin 31 to a 12V battery -, connect pin 15 to the battery +, and momentarily jumper 86 to 15, the relay should click each time you do this. for an even more thorough test, connect a test light from 15 (+) to 87a, and another test light from 31 (-) to 87. each time you tap 86 to 15, those lights should toggle (only one would be lit at a time).
So with taking some speaker wires and attaching one end of one of them to 31 and it's other end to the negative terminal of a car battery, and with taking the other speaker wire and attaching one side of it to 15 and it's other side to the positive terminal of a car battery, and then simultaneously temporarily jumpering 86 to 15 I heard no clicks.
I don't have multiple test lights to do the more thorough test.
I'm thinking this relay might be bad... especially since it was involved in the previous situation from a week ago where I had the power locks plug plugged into the O/D plug which was causing my power locks not to work. Maybe when I was trying to use the power locks it blew out this relay.
Originally Posted by pierce
then your black wire on pin 31 is NOT grounded properly.
the definitive relay test would be to take the relay out of circuit, connect pin 31 to a 12V battery -, connect pin 15 to the battery +, and momentarily jumper 86 to 15, the relay should click each time you do this. for an even more thorough test, connect a test light from 15 (+) to 87a, and another test light from 31 (-) to 87. each time you tap 86 to 15, those lights should toggle (only one would be lit at a time).
Yes indeed... I figured out I was reading the relay diagram backwards, in regards to the plug, when I just looked at the wires coming out of the plug and saw black (ground) was on the opposite side of where I thought it should be.
sorry volvodriver99 i misunderstood your initial post - thought it was that the trans would not shift into o/d (ie 4th gear), which is what
most folks ask about here when they say "o/d not working". anyway, looks like you are on the right track to getting the o/d lockout function working again.
might be the relay is ok after all!
