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Joined: May 2010
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From: Morgans Point Resort Texas
on 87
on my 87 and i believe the 88 it is on the firewall drivers side above lt exhaust manifold. there should be 2 relays held to a bracket with 10 mm nuts. one faces forward, the other should face to passenger side. The front one (facing front of car) should be the OD relay. The other should be the fuel pump relay. Check wires going into relay, due to heat they tend to loose insulation and could touch causing problems. Also OD will not work until the ECM see's 140 degrees.
Le Mans Master
Joined: Aug 2000
Posts: 8,838
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From: Australia
Does the O/d light on dash show up to show the computer is " trying " to operate the O/d ?
Have you checked fluid level in O/d ; low fluid will cause O/d not to operate
Or 176F in a '84
Have you checked fluid level in O/d ; low fluid will cause O/d not to operate
Or 176F in a '84
Last edited by rodj; Jun 20, 2010 at 08:25 PM.
Racer
Joined: Oct 2006
Posts: 355
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From: Concord, California
on my 87 and i believe the 88 it is on the firewall drivers side above lt exhaust manifold. there should be 2 relays held to a bracket with 10 mm nuts. one faces forward, the other should face to passenger side. The front one (facing front of car) should be the OD relay. The other should be the fuel pump relay. Check wires going into relay, due to heat they tend to loose insulation and could touch causing problems. Also OD will not work until the ECM see's 140 degrees.
Le Mans Master
Joined: Aug 2000
Posts: 8,838
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From: Australia
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Joined: May 2010
Posts: 89
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From: Morgans Point Resort Texas
I always read people saying the OD won't work until you reach a certain temp. I just had my "switch" replaced last year when the car wouldn't engage into OD once I pushed the botton. Now when I drive her, the car could have a temp of LOW on the digital cluster and the OD comes on as soon as I press the button on my shifter. I wonder how if it has to be 140 or 170 degrees as I've read before?
Thread Starter
4th Gear
Joined: Apr 2005
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Still having issues..
I have checked the fluid (it's full). The temp limit on mine is 122F. When I get to that temp I get the dash light which leads me to believe that the ECM is OK. The Shift button will turn the light on and off. I put a jumper from the O/D to 12v and it engaged... (good news). I looked for the relay on the firewall, but I don't know if I got the right one. I don't have two as one of the replies I got said I should. Any Ideas or suggestions would be great.. Thanks
