Question 1: "How can you refill 1995 Ford Windstar 3.8 Transmission Fluid?" -->Answer: Get a cheap funnel, and a flexible tube that fits inside the dipstick tube, but is large enough that your funnel can be inserted into the other end of the tube (Walmart sells both btw.) You refill the transmission through the dipstick tube. If it is EMPTY, look up the capacity specifications, and put in just that amount. If it is not empty, go slowly, check often. Transmission fluid level generally should be checked while hot (no, I do not know why.) DO NOT OVER FILL. Question 2: "Why, when I start my car, put it in Drive and press the gas pedal, can I hear the engine running but there is no forward engagement, and the overdrive (OD) light is flashing? --Answer 2: The OD light flashes whenever there is a problem code sent from the transmission system. Otherwise, I do not know the answer to #2; I am looking for same answer, and that is how I FOUND this question! Hopefully by fleshing it out a bit, I can help both the original asker and myself.
The OD light flashing is an indicator of an electrical failure in the transmission. Get it fixed now or replace the tranny later.
Four speeds on your transmission and the overdrive is when the engine speed and the transmission speed are engaged is a interchangeable load. running "free" sort of
It means that the truck in question has an overdrive transmission, as opposed to a direct drive transmission. All other things being equal, a truck with a direct drive and 2.64 rear ends is pretty much equivalent to running a .74 OD transmission and 3.58 rear ends.
Are you running 22.5s, 255s, 24.5s...? What's the final drive ratio of your transmission? Are you running direct drive (1:1), .87 overdrive, .74 overdrive...? What's your engine and displacement? You probably don't want to run the same gear ratios with a 12.8 Mercedes-Benz MBE as you would with a C15 Cat, you know? What kind of terrain are you running in? Are you doing east coast regional, 48 states, sitework...? Seriously, you're an owner/op or going to be one, and... this? 3.55s to 3.58s tends to be a bit of a 'default'. With a .74 overdrive transmission and 22.5s, you'd be running between 68 and 70 at 1500 RPMs. If you're running a direct drive with a 1:1 ratio and 22.5s, you'd be running 2.79s or 2.64s. Direct drive is disadvantaged in that you end up with lower starting torque, but also has an advantage in hills in that running a 1:1 transmission ratio doesn't create a parasitic drain on the engine (whereas running in overdrive does).
If your transmission is picking up a fault it will go into protection mode, No OverDrive, This may just be a solonoid or perhaps something more serios like a pressure problem. Long term running in this condition will most likely cause damage, A transmission service is a small price to pay when compared with a recon or new trans.
There are a few reasons why your daytime running lights are flashing. Your wiring could be messed up or your lights might be burning out.
if OD button is disabled, the transmission will not shift into overdrive. your car will be running with one less gear, and using more fuel
I just got home from the shop with the same problem, I was told that it has to be changed and its a dealer part only. Running an average of $475 just for the part. My check engine light came on and then the o/d light started flashing. To change it they have to drop the Transmission pan.
why don't any of my running lights work
It is possibly the overdrive solenoid located within the transmission. It prevents the transmission from downshifting and causes stalling at low speeds. It's a cheap part but a real hassle to change.
I doubt it is the tps. Could it be the transmission shifting in and out of overdrive?
If the check engine light is flashing when the engine is running , that indicates that an ignition misfire has been detected