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Installed 4.88 pumpkin and need to bypass o/d high altitude switch


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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?

20180707_155249.jpg

Edited by stevelark
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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. 

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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 by stevelark
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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.

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