Is there any reason why one couldn't use a toggle switch on the 7pin? Anyone done this?
This way you could have hard and soft tranny shifts in L.
This way you could have hard and soft tranny shifts in L.
Toggle Switch 7Pin Mod
- Thread starter landtoy80
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you would actually need to put a toggle on pin 9/19 (depending on year) to change shift points
this was discussed in an earlier thread but I have not heard of any one actually doing it
this was discussed in an earlier thread but I have not heard of any one actually doing it
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Yes, I have a switch. One way the center diff locks automatically when in low, with the higher shift points. Switched the other way, the center diff locks in low only when the CDL switch is depressed, and I get the lower shift points. If it's switched the first way, it doesn't matter what the CDL switch does, the center diff is locked no matter what.
The only config I don't get is the higher shift points with the center diff unlocked, that would require also switching the 9/19 like Raven suggested. I've had many a long chat with my favorite parts guy about doing that, he's your man if you want the official low down. But installing the switch is easy, you don't even need to pull the wire from the connector, just cut it and "tap in" with a switch.
The only config I don't get is the higher shift points with the center diff unlocked, that would require also switching the 9/19 like Raven suggested. I've had many a long chat with my favorite parts guy about doing that, he's your man if you want the official low down. But installing the switch is easy, you don't even need to pull the wire from the connector, just cut it and "tap in" with a switch.
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exactly, so switching pin7 gets you one step closer to that, where you get it all except for unlocked in low with high shift points. Switching 9/19 is the final hurdle. Then all you need to do is remember what switched what gives you what... I wheeled on Saturday and forgot all about the pin7 switch, just used the one on the dash and the lower shift points all day.
Nak, I don't quite follow what you are saying. I believe that the disconnecting or switching "off" pin 7 only prevents the center diff from automatically locking when the transfer is shifted into low range. Or are you switching wires other than pin 7?
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No, I'm just switching pin7, but what happens is the shift points change. It's not that drastic, kind of like switching to "power" mode in low range... it's been a while since I've done the comparison, but I remember that's how it was right after I did the switch. I guess I could find a dirt road somewhere, try it both ways and post some numbers.. but not tonight, I'll do it tomorrow if I don't ride my motorcycle..
If you are switching the black/blue wire between splice point I 11 and pin 7 of the connector to the center diff lock control relay then all that should do is interrupt power to the relay which would otherwise automatically lock the center diff. Your switch should not have any effect on the transmission shifting.
If you are getting a difference in shifting depending on whether or not your switch is open or closed, then you must be switching the black/blue wire somewhere between the transfer position switch and splice point I 11, which would then (when your switch is open) also block the "transfer case is in low range" signal from going to the engine control module on pin 9 of the engine control module connnector.
The motivation for removing the pin 7 black/blue wire from the connector on the transmission control relay is to avoid the behavior that you are observing.
If any of this is not clear, a review of the factory wiring diagram should help. I am presuming that the wiring for the '96 is the same as for the '97.
If you are getting a difference in shifting depending on whether or not your switch is open or closed, then you must be switching the black/blue wire somewhere between the transfer position switch and splice point I 11, which would then (when your switch is open) also block the "transfer case is in low range" signal from going to the engine control module on pin 9 of the engine control module connnector.
The motivation for removing the pin 7 black/blue wire from the connector on the transmission control relay is to avoid the behavior that you are observing.
If any of this is not clear, a review of the factory wiring diagram should help. I am presuming that the wiring for the '96 is the same as for the '97.
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test results, pin7 switch:
Ok, pin7 geeks, so as promised I took the truck out to a dirt road today during my lunch break and performed a series of shift point tests. Flat, dirt road, light washboards, tested several times going both directions. I started from a dead stop each time, I'd depress the gas pedal then pull the hand throttle out all the way and lock it, that was the best way I could think of to be consistent there, short of just flooring it each time. Stock gearing, 295 75's, and I haven't done any speedo gear or truespeed calibration, still all stock there.
Pin7 switch "off," stock configuration:
-Shift between 1 and 2 almost always occurred between 2000 and 2200 rpm's. Shifts between 2 and 3, and 3 and OD then occurred around 1800-2000 rpm's.
Pin7 switch "on," or in the disconnected "pin7 mod" configuration:
-Shift between 1 and 2 occurred around 2000 rpm's, sometimes as low as 1800 rpm's, but other times as high as 2200. So a little more variation, but the average was lower. Shifts into the other gears all occured at 1800 rpm's or below, with few exceptions.
So Rich you're probably right, it's likely that all I'm doing is using a different switch to activate the CDL, so to speak. I still think it shifts at a slightly lower point when the pin7 mod has been activated, but it was less apparent today than it was last fall when I put the switch in. If anyone else wants to try, again it's almost easier to just clip the wire and install a switch than it is to dig the pin out of the connector, so try it yourself and post your results. And if you're ever on a run with me, hop in and you can try it both ways first hand
Ok, pin7 geeks, so as promised I took the truck out to a dirt road today during my lunch break and performed a series of shift point tests. Flat, dirt road, light washboards, tested several times going both directions. I started from a dead stop each time, I'd depress the gas pedal then pull the hand throttle out all the way and lock it, that was the best way I could think of to be consistent there, short of just flooring it each time. Stock gearing, 295 75's, and I haven't done any speedo gear or truespeed calibration, still all stock there.
Pin7 switch "off," stock configuration:
-Shift between 1 and 2 almost always occurred between 2000 and 2200 rpm's. Shifts between 2 and 3, and 3 and OD then occurred around 1800-2000 rpm's.
Pin7 switch "on," or in the disconnected "pin7 mod" configuration:
-Shift between 1 and 2 occurred around 2000 rpm's, sometimes as low as 1800 rpm's, but other times as high as 2200. So a little more variation, but the average was lower. Shifts into the other gears all occured at 1800 rpm's or below, with few exceptions.
So Rich you're probably right, it's likely that all I'm doing is using a different switch to activate the CDL, so to speak. I still think it shifts at a slightly lower point when the pin7 mod has been activated, but it was less apparent today than it was last fall when I put the switch in. If anyone else wants to try, again it's almost easier to just clip the wire and install a switch than it is to dig the pin out of the connector, so try it yourself and post your results. And if you're ever on a run with me, hop in and you can try it both ways first hand
