stevelark Posted July 7, 2018 Share Posted July 7, 2018 (edited) Hello all! I've owned my 86 new horizon for 7 years and I've relied on this sight for soooo many things, so thanks to you all! I finally pulled the trigger and had a true 1 ton floating axle and had the pumpkin regeared to 4.88. Just climbed from Reno NV (4500 ft) to Mono county (7500 ft) and couldn't believe how the RV climbed the hills with the new gears. The problem, as I'm sure you've guessed, is my top speed. I am cruising at 55mph at 4000 rpms. Due to the elevation my overdrive doesn't work. I've searched other threads but have not seen a pic of the altitude lockout. Here is a picture of mine, which two wires do I connect? Do I remove the connector and jumper or leave it connected and jumper? Edited July 7, 2018 by stevelark Quote Link to comment Share on other sites More sharing options...
Maineah Posted July 7, 2018 Share Posted July 7, 2018 I believe it's part of the map sensor circuit (manifold absolute pressure sensor) meaning it is connected to the engine management and the ECU controls both the engine and the OD lock out from the same sensor input basically it's reading barometric pressure higher altitude lower pressure. Quote Link to comment Share on other sites More sharing options...
WME Posted July 8, 2018 Share Posted July 8, 2018 Here ya go http://toyotamotorhome.org/forums/index.php?/topic/4012-auto-trans-altitude-od-switch/ Quote Link to comment Share on other sites More sharing options...
stevelark Posted July 8, 2018 Author Share Posted July 8, 2018 (edited) Thank you for the link WME but this thread doesn't specify which two terminals to jumper, other than the top two. I've taken my best interpretation of that and have jumpered the blue and black with yellow stripe. Crossing my fingers that this is correct. I'll report my findings to the group. Edited July 8, 2018 by stevelark Quote Link to comment Share on other sites More sharing options...
Maineah Posted July 8, 2018 Share Posted July 8, 2018 If you remove the OD solenoid at the back right side of the transmission and take the lower small "O"ring off OD will all ways work. Hate to tell you this but with 4:88 gears you are not going to gain much. Quote Link to comment Share on other sites More sharing options...
stevelark Posted July 10, 2018 Author Share Posted July 10, 2018 On 7/7/2018 at 9:52 PM, WME said: Here ya go http://toyotamotorhome.org/forums/index.php?/topic/4012-auto-trans-altitude-od-switch/ I was able to bypass the lockout and my overdrive kicked in! Works amazingly well with the 4.88 gears. I can now climb hills and also cruise down them at 60mph at 2500 rpm. This combo is a game changer. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.