Dash goes dead when rpms increased and No Reverse

[houptee]

2005 Explorer XLT 4x4 6cyl Automatic.

Problem started a while ago, Check charging system message comes up, and all gauges drop to 0, i.e. speedometer, tach, a clicking noise behind dash can be heard, then if you let off the gas pedal they come back on again.

Put new battery in few months ago and seemed ok but now doing it again. Disconnected batt cables and charged battery for a few hours. No change same issue.

This is a secondary problem to the transmission problems.
Trans had a whining sound like a power steering pump.
It would not go into Drive or Reverse, it only goes into low 1 and 2. I got it up on ramps and dropped pan, fluid was black and magnet was covered in 1" thick sludge. Changed filter, and cleaned magnet and pan, put 5 qts Mercon V. Whining sound is now gone but it still has no Reverse, but now has Drive.

While letting it warm up after trans service, the dash problem started acting up again really bad. If I put it in R and try to increase rpms to see if it will engage the dash goes dead, and engine starts to choke out. In any other gear, engine does not choke out, but dash goes dead and check charging system flashes as you increase rpms.

No idea what the coincidence is with this electrical issue coming back to life after doing a trans filter service.

Anyway it seems like the transmission is shot but would like to determine the electrical issue or if it could be causing the no reverse.

Thanks for any advice!

 

[Number4]

These cars run more than one signal down a wire. So the wires to the gauges may share info for the trans etc. So a bad component elsewhere may be the issue. Seeing as how the trans is symptomatic, I'd start there. Trans control solenoid (not the solenoid pack,) transmission range sensor, accelerator pedal position sensor, etc.

In my experience, AAMCO's will check the trans no charge, if no problems found.

 

[houptee]

Thanks I will see if the Neutral Safety Switch i.e. range sensor has any effect if i somehow can test it but it has 11 terminals so hard to jumper various wires to test it without full pinout schematic.

Do you know where that trans control solenoid is located? Under hood or under car?

Thanks!

 

[Number4]

I do not, but the part number at NAPA is ECH TCS636. Go online and you can see a pic of it at least.

 

[houptee]

I charged battery for few hours and started it again today, same thing, dash powers up, few seconds later the red battery light comes on, then the check charging system message, then dash clicks and powers off. The only dash light that stays lit is the airbag light. When dash powers off the windows and radio also power off.
I put digital voltmeter on battery and found the alternator voltage regulator must be bad since the voltage when running is almost 18 volts!

The high voltage might be the problem with the transmission not going into Reverse since there are variable pressure solenoids inside the 5r55s transmission that use the PCM to vary the valve and pressure to make it shift.
It could also be the Range Switch is bad.
Here is a great article about these transmissions
http://www.valvebodypros.com/pdf/Ford5R55WS_Understanding_the_Initial_Engagements.pdf

I will replace the alternator first. It was changed a few years ago and Advance Auto Parts has a lifetime warranty so they should give me another one for free. I will see if that helps before trying any transmission electrical parts.

 

[houptee]

Replaced Alternator and now dash power off problem is fixed. Electrical seems fine now.
The transmission still will not shift into Reverse.
I am going to try replacing the neutral safety / range control switch next as the pressure control solenoid is inside the transmission as far as I can tell by looking at it.