Looking at a 93 putz that engaged into pump mode fine operated well but wouldn't go into drive mode at all. Truckhas been sitting about 2 years with only gitting startes occasionaly.

 Went back yesterdau and they had switched air lines so I could drive it, now doest go into pump mode. There is a switching block (sounds like a good name to me.)that is activated by the electrical switch in cab to engage the pump mode has several airlines coming of of it, they are replacing it monday. The new one has bypass valves on it to switch manualy in the event of a failure- or so im told, does this sound correct.?

it sounds like the same system that are on are putz's....

You will find the post about Putzmeister PTO air valves, the older valves did have a manual way to shift them but it wasnt all to obvious, as you will see in the post, the new style is a lot easier.

If it shifts fine manually then I would suspect the issue to be in the Mack cabin. There is a power supply fuse sending power to the PTO switch Pin 2 this goes through an air switch on the back of the Maxi Brake valve, you will need to check them both, I did a post a while back on this I will dig it back up look for it soon. If you don’t have power on Pin 2 of the Pump/Drive switch this is most likely your problem.

It would help to have the serial number of the unit to get much deeper with you, you could E-Mail me or call me if you need help with this deeper, or call PM Customer Support @ 800 890 0269

Alan AKA Travelteck      woodsa@putzam.com      360 600 5695

This is why I might need the serial Number for your unit. In the Mid to late 90's to 2000's this is the location of the PTO Fuse

I dont want to send you on a goose chase if you have a unit that is wired diferently, but if you have this style of fuse pannel this might be your fuse, I am pointing at the 15 Amp breaker you might have to look real close there might be a small Push in automotive fuse in there, this is ok, they were prefering the fuse over the breaker anyway so just replace it if it is blown, NO BIGGER than 15 AMP.

This is just a closer shot of the same Fuse/ Breaker

For the rest of you reading this it is good to locate this fuse and MARK IT!!!!!!!!

Finding this fuse in a panic in the dark while concrete is arriving is not a good time.

It is normal to find the Breaker has been replaced with a 15 Amp Mini Fuse, this is ok and actualy preferable to the breaker.

To be sure you have the correct fuse you can AT THS SHOP, shift the unit in and out of PTO, Remove the fuse and you should loose PTO replace the fuse and now you are sure you have it correct.

Never pull the fuse under load, Take the unit out of PTO then pull the fuse. If you are not sure turn off the Mack.

Simple things like this can save a lot of aggravation on site, be safe and carry spare fuses.