Tow Haul No Longer Works After Neutral Safety Switch Replacement

[adam_murphy]

A while back i replaced the neutral safety switch in my truck. After that, i noticed that tow haul stopped working, as well as the OD lockout. Also something odd that if i happen to put it in 4 low, it will automatically go into tow haul mode, and wont come out of it until the truck is shut off. Would like to get all this little crap working before spring time where i use the truck the most.

 

On a related note, i see that the allison neutral safety switch has a vaccum port on it? I capped that off, would that have anything to do with it?

[gmtech4]

A while back i replaced the neutral safety switch in my truck. After that, i noticed that tow haul stopped working, as well as the OD lockout. Also something odd that if i happen to put it in 4 low, it will automatically go into tow haul mode, and wont come out of it until the truck is shut off. Would like to get all this little crap working before spring time where i use the truck the most.

 

On a related note, i see that the allison neutral safety switch has a vaccum port on it? I capped that off, would that have anything to do with it?

 

its not a vacumn port ,its a breather for the switch,all the other stuff makes no sense to me ,make sure you have the switch adjusted properly,you may have a DTC ,enjoy

[adam_murphy]

A while back i replaced the neutral safety switch in my truck. After that, i noticed that tow haul stopped working, as well as the OD lockout. Also something odd that if i happen to put it in 4 low, it will automatically go into tow haul mode, and wont come out of it until the truck is shut off. Would like to get all this little crap working before spring time where i use the truck the most.

 

On a related note, i see that the allison neutral safety switch has a vaccum port on it? I capped that off, would that have anything to do with it?

 

its not a vacumn port ,its a breather for the switch,all the other stuff makes no sense to me ,make sure you have the switch adjusted properly,you may have a DTC ,enjoy

 

 

got no email to the reply:( what is confusing about this? I'll try to explain better, it doesnt work when i hit the button, it'll randomly come on if i put the truck in 4 low. In the event that it does come on, it wont shut off with the button, and will only shut off when the truck is shut off. I dont know how it could not be adjusted correctly, i left the truck in neutral when the old switch came off and when i put the new switch on.

[adam_murphy]

also, does that breather for the switch need to be left open? i have it capped off right now

[gmtech4]

that tow /haul harness often do break ,pop of your knee bolster(under steering column),follow the harness out of the shifter,it doesn't go far,if there is a break ,you will see it,if ok,have it scanned,if its broke,the shifter arm needs to be replaced ,easy with cluster trim off & steering column trim off.and knee bolster off.