Overdrive not working... '87 Ram50

[Maynard70]

Gentlemen...

Been trying to figure out why my O/D never seems to want to kick in. I can play with the button on the end of the shift lever as well as feather the throttle all day long, but nothing. The little orange idiot light on the PRNDL pod comes on occasionally, but the trans doesn't want to go into 4th.

Now I've read where there's a connection on the upper radiator hose housing on the block you can ground out or something that might fix this, but there's two connections I can see. Which one is it, A or B... What do I need to do? Picture provided!

Thanks in advance for any info...

M.

[pennyman1]

That is not where the sensor is - there is one in front of the carb on the top of the manifold that has 1 black wire on it. To see if the sensor is the problem, take that black wire and ground it to the manifold on the connectors on the side of the intake under the carb. This will give you O/D when the O/D button is depressed in on the column shifter, regardless of the temp of the motor. The sensor is there to delay O/D until the motor is at operating temp for emissions.

[Maynard70]

Thanks for info!

I think I found the right wire you're talking about, but grounding it did nothing; still no O/D.

Is there any other component I need to look at, or perhaps add or change out trans fluid, etc?


M.

[pennyman1]

does the O/D indicator come on in the tranny indicator hood on the column when you cycle the button on the shifter?

[Maynard70]

The "OD OFF" light (usually) doesn't work, regardless if the shifter button is in or out, but I have seen it flicker on occasionally. In fact, the PRNDL pod gear indicator light doesn't work, either; scattered electrical issues left over from PO that I haven't been able to trace down, but that's another story for another day. :shrug:

[pennyman1]

check the fuse holders and fuses - the contacts to the fuses lose tension and the fuse is no longer in the circuit. Check the fuses too - if the fuse holders are loose, they can vibrate the fuse and ultrasonically melt the solder in the end of the fuse, making it open. It will look good, but be bad.

[Maynard70]

Don't think its the fuses... Checked all of 'em (at the lower dash access) and they're good.

Oh well, it's not really a HUGE deal. One of these weekends I'll get bored and grab my meter and start tracing down circuits and try to figure out what the PO did or un-did... there's a maze and rats-nest of DIY wires and splices and patches and add-ons and switches under the dash and in the engine bay that he did that I have no idea what they're for. My speedo and gauge lights don't work, a switch was rigged up for the lights, and a push button for the starter, so maybe I'll start there.

But as for now, the thing starts, runs and gets me to work, so, ya know... Thanx for the help.

M.