[leeschu1]

Something is discharging the battery of my 2007 Ford Taurus. My meter shows a loss of 1.6 amps.
My instrument cluster display says "check transmission"; the transmission fluid is OK.
The tachometer needle was vibrating 500-600 rpm before the engine is running. (Once when
I came to the car to get something from the glove box, the tachometer needle was vibrating
500-600 rpm even though the key was not in the ignition.) Now the tachometer needle does not move
even when the engine is running.
I can't find any bare wires in the wiring harness.
Does anyone have any suggestions to help me with this problem ?

 

[rjacket]

For the transmission, you need to read codes.

For the discharge, you need to remove fuses one by one and see if your reading drops.

 

[helifino]

fuses are resistors, you can also read a mV across the terminals if there's an active load.

 

[chartmaker]

fuses are resistors, you can also read a mV across the terminals if there's an active load.

Ok but need good VOM thar can read x.000 or milivolts.
-chart-

 

[leeschu1]

For the transmission, you need to read codes.

For the discharge, you need to remove fuses one by one and see if your reading drops.

Thanks for your suggestions.

Before checking the fuses, I replaced my 2007 Taurus cluster with a 2006 one.
This reduced the 1.6 amp discharge to 0.70 amp; the "check transmission" message remained,
At startup there is a slight vibration on the speedometer gauge (0-1 mph) for a few seconds.

Removing 15A fuse 33 (Hazzard Flasher, Cluster power, {CP Power, EATC) brought the discharge to near zero.

Any further suggestions ?

 

[rjacket]

Thanks for your suggestions.

Before checking the fuses, I replaced my 2007 Taurus cluster with a 2006 one.
This reduced the 1.6 amp discharge to 0.70 amp; the "check transmission" message remained,
At startup there is a slight vibration on the speedometer gauge (0-1 mph) for a few seconds.

Removing 15A fuse 33 (Hazzard Flasher, Cluster power, {CP Power, EATC) brought the discharge to near zero.

Any further suggestions ?

Next step will be to disconnect each of those three things one at a time to see which one is drawing the 0.7 amp.

Simplest thing to try first would be switching the hazard flasher button on and off to see if that results in expected changes.

Do you have wiring diagrams that you can look at?

 

[helifino]

Ok but need good VOM thar can read x.000 or milivolts.

I don't think I've ever spent more than $20 for a vom and every single one (including the "pocket" models) has the mV range on it.

 

[chartmaker]

I don't think I've ever spent more than $20 for a vom and every single one (including the "pocket" models) has the mV range on it.

I have one that reads 0.0000 V. But that is never used. It is high end "True RMS" and has lots of thing it can do. I would not spring for this new, but fund at a yard sale on the cheap.
As to volts drop over a fuse to tell if there is current through it. I used my current source set at 1 A and ran that through a 30A fues and 3A fuse. Drop was 2 mv and 30 mv.
Pulling fuses under the ist. panel is a pain. Last time I did that I dropped one and it fell under the carpet. By by.
-chart-

 

[rjacket]

Here is the official wiring diagram for your fuse 33. You can see 4 things connected to fuse 33 including the multifunction switch. Each of these 4 things has its own connector.