[Big_pete_cummins]

So I replaced the overdrive solenoid on my truck because it worked when I bought it a couple weeks ago but then it stopped after a couple days use. I replaced it just now and it still doesn't want to shift into overdrive. On another note my speedo is starting to jump all over the place which started before I installed the new solenoid today. It will stay then jump and when it jumps it moves the battery Amp meter and it dims and brightens the lights and it also flickers my left turn signal. I have no idea what could be wrong with it. My guess is the vss but what could cause those to go bad? Like would drifting on gravel roads cause it to get rounded off? but I don't know why it affects the lights and stuff.

 

[Blackduck59]

Don't know diddly about the OD but if the amp meter moves and the lights dim I would say you have a power issue.
Bad terinmals, bad connections, bad wiring, bad alernator or a short in the wiring. This also includes the ground connections.

 

[Big_pete_cummins]

Where should I check for those things because I tested the resistance of the wires coming off the battery and they both seemed fine and I measured the voltage and they both seemed to be transferring it fine too, but I realized it only moves/jumps and shows everything after the trans is up to temp and I put the pedal to the metal. Any thoughts?

 

[sdeeter19555]

I'd be looking at every ground you have...there is one or two under the dash that ground the cluster and radio. Once you have that voltage fluctuation fixed, then chase your cruise issue.

 

[jbdavi211]

Hello, so the speedo drive gear is on an eccentric and you line it up with the mark for your speedo gear, If I remember right it goes by color of the gear if it is lined up wrong it will jump teeth. That is what I found that made my speedometer jump around. if your lights dim in a pattern/pulsate I would say you have a bad phase in the alternator. it will still charge but will flicker the lights a bad phase would induce a hum into the radio that speeds up as you put more throttle to it.. And of course the grounds. it could also be an issue with your ECM on the inner fender well. IMHO

 

[Ruderunner]

The flickering turn signal is a big clue that you have a ground problem. Most likely the core support one.

Iirc the ecm grounds to the support. If that's flaky the ecm basically shuts off and turns back on. When it does that, no speedometer, no charging, od etc.

Try driving at night with the dash lights off, watch if the check engine light flickers too.

 

[Big_pete_cummins]

I fixed it it was a ground issue just one of the grounds came loose. Thanks. But I still don't have overdrive. I have no idea why.

 

[Big_pete_cummins]

I even tried just jumping the solenoid wires to the ground to make sure it was getting a ground and it still wouldn't shift.

 

[9297oldram]

Did you try bypassing the OD switch on the side of the block on the drivers side? It prevents the OD from going in until the engine gets to around 100 degrees.

 

[Big_pete_cummins]

Do you have a picture of it?

 

[9297oldram]

It screws into the side of the block just under the cyl head in front of the fuel filter. I can try and find a picture later if you still can't find it.

 

[9297oldram]

There is a picture somewhere on the internet showing the sensor but I can't find it again. It's hard to see but it screws into the water jacket of the block and has 2 wires on it that control the OD from coming on when the trans is cold. Most will just bypass the sensor and connect the 2 wires.

Page 898 in this FSM it's called the coolant temp sensor, and it's behind the fuel filter in the side of the engine. It shows a picture of the location. Go to the 1993 FSM

First Gen - Google Drive

drive.google.com

 

[Sheep Herder]

Temperature and Overdrive????? - Dodge Diesel - Diesel Truck Resource Forums

1st Gen. Ram - All Topics - Temperature and Overdrive????? - I have searched the DTR forums, and also Googled, for an answer, but I am simply not finding an answer that matches the situation. My truck, 1992 D250 (2WD) A-518 trans... when cold, it will not stay in overdrive. It sort of acts like...

www.dieseltruckresource.com

 

[sdeeter19555]

I even tried just jumping the solenoid wires to the ground to make sure it was getting a ground and it still wouldn't shift.

The OD solenoid is switched by ground, it has positive (+) power all the time.