dodgethis91cmns

Ok so I'll try to make it short sweet and to the point as best I can.

I recently put my truck back on the road after many years of it waiting its turn to be finished. It's a 97 ram 2500 2wd nv4500 single cab , with 201 xxx on the clock. I installed a big input southbend dual disk, turbo, wheels tires blah blah blah.

Well after 111.6 miles of breaking it back in, I noticed my speed and odometer just quit. No ABS light no air bag light like I've a lot of people have pop up under this condition.

First thing first I pulled the transmission speedo drive sensor, cleaned it re installed.....nothing

Next I pulled the rear diff wheel speed sensor, cleaned it...nothing.

Okay.....next I replaced both sensors with new ones, still nada

Next I re clocked the speedo drive the tail shaft drive gear, I also thoroughly inspected both gears, no effects that I. Could see in either of them.

NOTE, the only thing I noticed, is when you look in the hole of the tailshaft housing where the sensor housing goes in, the tailshaft drive gear was about an 1/8 inch off enter to the left (toward the front bumper)

After that I traced some wiring back and fond driver side between the IC and the fender well a bundle of wires had been pinched. I crack the loom open and find BLACK/ LT BLUE tracer chaffed to the copper. I know that's the sAme color as the middle wire on the speed sensor. Patch it up , nothing


Ok, grab the snap on test light with built in volt meter , I get 3.9v and 7.1v...from what I've read I should have gotten 5v and 8v

Last ditch diag. Effort...I slap the scan gauge in....hers what I notice

-I have no MPH input which I would think rules out my cluster being bad
-water temp is glued at -40 thermostat cycles fine on the dash gauge
-from the dash tachometer vs. the scan gauge, the scan gauge is low by about 200-300 rpm when I'm rowing gears from a light until up to highway speed or back to idle.
- with my air on full blast, wipers on high, radio on high beams on, the scan gauge reads 13.2-13.3v MAX. With the loads off it reads 13.5 MAX

MY QUESTION IS...could my alternator be my problem? And outside of the aforementioned procedures....anyone's insight IS GREATLY APPRECIATED
Because I just want a speedo so I can get my truck inspected

Busboy

Make sure that the ground wire to the body is in good condition and no corrosion. Then try the instrument cluster test.

Insert the key into the ignition and rotate it one click forward to the OFF position. Push and hold the odometer reset button and then turn the key one click forward to the ON position while continuing to hold the reset button in. This will start the test:

- The odometer will read CHEC (you can let go of the odometer reset button here). The Wait To Start, Air Bag, and ABS lights should also light during this step. The PCM controls the instrument cluster, but the ECM, airbag module, and ABS module will function like normal during this which is why their lights are lit at first.

- The odometer will then change and read all 8's. The CRUISE and TRIP indicators under the digits will also be lit. No other indications will be lit during this part of the test. This lasts for about 5 seconds.

- The odometer will then test each and every segment of its display in sequence

- After that, every indicator on the dash will light up, with the exception of the Wait to Start light, turn signals, and high beam indicator. The WTS light is under control of the ECM which is why it does not light during this part of the test.

- The indicators will go out and then all of the gauge needles will move together in three steps. ¼ scale, ½ scale, and then full scale. The exception here is the fuel gauge, it will read 1/8, then ¼, then full.

- The gauges will go back to zero and the test is over. The door chime will sound and the instrument panel will return to normal.