Lost 1st and 4th

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1993 ld2500 4l60e, I lost 1st and 4th. I replaced the A and B Solenoids only to test the old ones afterwards and find out they were still good the trans is only a few years old and was rebuilt with extra clutch packs, the fluid looked good but I changed out that and the filter, what are my next steps? Idle Air Control Valve? What tests can I run without an OBD1? any help would be greatly appreciated
 

alpinecrick

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1993 ld2500 4l60e, I lost 1st and 4th. I replaced the A and B Solenoids only to test the old ones afterwards and find out they were still good the trans is only a few years old and was rebuilt with extra clutch packs, the fluid looked good but I changed out that and the filter, what are my next steps? Idle Air Control Valve? What tests can I run without an OBD1? any help would be greatly appreciated

Sounds like you are in Limp Mode. Most often limp mode is caused by the ECU not getting a signal. A pinched wire that had escaped the plastic wire loom after installing a filter put mine into limp mode.
 
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So this happened directly after my alternator went bad just last week so I'm wondering if something to do with that made the ECU shot off power to the trans and just never let it get power back. I'm gonna disconnect my battery for 30 minutes and see if it changes anything
 

jjester6000

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Solenoid A on your transmission is bad (or there might be a wiring issue).
1st Gearsol A = ONsol B = ON
2nd Gearsol A = OFFsol B = ON
3rd Gearsol A = OFFsol B = OFF
4th Gearsol A = ONsol B = OFF
Here's the 4l60e's shift Logic.
 

jjester6000

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Solenoid A on your transmission is bad (or there might be a wiring issue).
1st Gearsol A = ONsol B = ON
2nd Gearsol A = OFFsol B = ON
3rd Gearsol A = OFFsol B = OFF
4th Gearsol A = ONsol B = OFF
Here's the 4l60e's shift Logic.
A while back, as an experiment, wired up the 4l60e in my '95 Burb to work without a computer by adding manual switches for Solenoid A, B, and the lockup for the torque converter.
You must be registered for see images attach

You either got a bad solenoid, or a wiring issue.
 
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I think it has an electrical problem because both solenoids are brand new and tested good before they were put in the truck, and after the battery is disconnected for 30 minutes it works properly only until it shifts out of first the first time, after that I only have 2nd and 3rd
 

618 Syndicate

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I think it has an electrical problem because both solenoids are brand new and tested good before they were put in the truck, and after the battery is disconnected for 30 minutes it works properly only until it shifts out of first the first time, after that I only have 2nd and 3rd
So once solenoid A shuts off, it isn't coming back on. Reset it and it will come on, but once it's off for 2nd gear it's done.
 
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So I didn't know this but if you bridge the obd1 scanner prongs (the two on the top row and furthest on the right) and the check engine light flashes a certain amount of times to give you your code I got 6 flashes and another 6 flashes, that's code 66 which indicates an open or short circuit in the 3-2 solenoid, now that it's narrowed down what should my next step be?
 
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