Hello! In 1995, some radios had the option of Speed compensated Volume, and therefore there is a speed sensor signal going to the radio. There may be a connection for this wire at the radio, even though the radio doesn't use it and I suspect that the Sony head unit is either applying voltage to this circuit, or grounding it, which can wipe out anything that shares that circuit (speedo, transmission, cruise control, etc...)
You need to find the Dark Green w/ White tracer wire and make sure its NOT connected to the radio.
Shop Foreman
GM
OK, can I get a list of the colors of the speaker wires so I can match them up to the schematic? this will help me determine every wire hooked up is where it belongs, and also which wire from the radio is each factory wire connected to.
Factoy harness speaker wires.....LF =gray/tan RF=dk green/ lt green LR= yellow/brn RR= blue/ lt blue
adapter radio harness. LF=wht/ wht-blk RF=gry/ gry-blk LR=grn/ grn-blk RR=prpl/ prpl-blk
Power Wires factory harness. BATT/orange IGN/yellow GRND/blk
power wires adapter harness BATT/yellow IGN/red GRND/blk
purple, green, green/w white tracer, not used on factory harness. does the orange (illumination) wire on the adapter harness need to be connected to corresponding (grey) wire on the factory harness? if so where do i connect it to the radio? thank you for your help.
OK, it seems as though its hooked up correctly. You don't need to hook the illumination circuit up. Not all radios support that, its up to you. Its just for radio dimming purposes at night.
Lets try and isolate the circuit, one by one. Start with the IGN signal (yellow on the factory harness) and disconnect it, leaving all others connected and see if the trans operates normally again. Then go to the battery (orange wire) and see if that changes.
You don't need to do that with the ground wire, but it wouldn't hurt if you gave the radio its own ground.
Do that to each wire, one at a time and see if any wire disconnected restores operation.
performed request and nothing changed, only when i install factory radio, the truck runs correctly. does somthing need to be done to green/white wire to make it think its hooked up, does the icp not recognize the radio, or the green wire disconected. thank you
You are correct, this should be a very easy install. Under normal conditions, the truck does NOT need the radio, so we have to try and figure out whats different about your truck.
Do you have a test light?
I beleive these grounds may be part of the problem. It sounds as though other components that share the ground, may have been grounding out through the factory radio. With no radio or aftermarket radio, the ground is lost. I have seen that before, but not on a radio!
The grounds near the thermostat housing are G103 and G104 I'll post the schematics for those grounds, and items like the speed sensor buffer and other related items DO ground right there.
I would fix these grounds, and maybe even add a redundant ground at the radio connection and you should be set!