Hello all. New to the forum, first post right here.

So..... I have a 1997 s-10 blazer. 2wd. 4l60e.

Just got it about a month ago. had some wiring issues at the vcm. I am an electrician by trade so fixing the wires was easy. Now i am having tranny problems. Hopefully someone can help me.

Heres my problem, While the key is "on" the shift indicator light on the dash works in all gears and fuse #24 is fine.

When its running, in park, and i shift to "R", the fuse blows.

If i start in "N" i can shift into "OD" "D" and "2" But if i go into first, fuse #24 blows.

Also if i start in "N" and go into reverse, the fuse also blows.

Ive read alot of posts on here and another site, but have not come accross this specific problem.

I have all the codes of the tcc/pmw or whaever being bad, but i assume those would also come up if the tranny lost power via the fuse blowing.

Also, if i unplugged the harness on the passenger side of the tranny, i can start it and shift thru every gear without blowing the fuse. By that alone i figure its internal, BUT, which soleniod controls 1st and reverse?

Any help is greatly appriciated. i would love to get this thing on the road. Thanks in advance.

 

Taken from swartlkk:
The shift solenoids (A & B) control fluid flow in the transmission to make the necessary shifts. In 1st, both A & B are energized. For 2nd, B is energized. For 3rd, neither are energized, and for 4th, A is energized. Also, the 3-2 solenoid is energized in all but 1st gear.

There is no solenoid for reverse however. You most likely have a problem with the shift selector switch on the driver side of the transmission or else a short to ground on those two wires. The hard part is figuring out which wires they are. I would start by checking up near the top of the bellhousing and see if the harness is pinched.

However when you pull the round harness on the pass. side, the transmission will default to max line pressure since it is electronic controlled. Solenoids are not operational at that point.

 

Ok. Ive already replaced the neutral safety switch. ive checked the wires as best i could. They are a pain in the *** to get to. I didnt see any issues there.

But there is a possibility that one of the 10 wires that go to that switch could be shorted to ground?

If its one of those, why does it only blow the fuse when the solenoids are plugged in?

Im just confused with this whole thing. lol. I had a 91 ex. cab that I knew evrything about. Now i got this thing and its nothing like my other one. So now im kinga starting new.

Ill go check those wires and see if anything comes up grounded. Should any of them be grounded? Or do they all provide power to something?

Pin "F" and "C" have connectivity to ground. One wire is pink and the other is green. Only by the other problems I've come across, Isn't pink usually a power wire? Or is that only with the injectors?

 

Have you done a full inspection of the wiring harness anywhere close to the shift linkages under the dash as well as on the transmission?

 

The reason I thought to narrow it down to the selection switch is because the solenoids operate if you have it in OD. If it works fine in OD but not if you manually select 1st, that would lead me to believe there is a problem with the switch. Unless something changed from '95 to '97 as far as solenoid operation or the switch, I don't know what else to say.

In the last harness I did PINK was switched +12V and Orange was battery +12V. That was on an '02 Camaro though. Green is most likely an I/O signal to/from the ECM.

 

i have inspected the wiring under the dash. everything under there looks good. everything seems to work fine. the white wire from the ignition switch looks to have gotten hot at the ends, but it has continuity and even voltage for the length of it. im at a loss here. i dont want to replace the valve body if thats not the issue. but im prepared to if that comes to be the problem.

i have already done the fuel pump and filter, the spider injector, the MAP sensor, the nuetral safety switch and the VCM.

 

Did you check the internal wiring harness for the transmission? Long shot, but maybe the valvebody harness got pinched. It may be easier to drop the pan to check that. But if you have just about every wire on the controller figured out it may be easy to check it from there instead.

 

I have checked most of it. Everything i could get to. I have some friends coming over tomorrow to give me a hand. We found all the plugs and wires on ALLDATA. So we are going to go thru each wire and make sure the power ones have power, grounds have grounds, the vcm ohms out correctly, and all that mumbo jumbo. And if nothing comes from that, Then we are going to pull the pan and see if we can figure out something on the inside.