daveg

Driving down the road the tach will cut out for a few seconds up to several minutes, also seems a little sluggish when it does. I've poked around checking for loose connections, etc., nothing apparent.
Is there someplace in particular I should pay extra attention to ?
Thanks !

Hemi Cat

Check the gap on the mag pick up. I set them to .010". Clean the pick up and balancer ring. If problem continues, check the wires, connections, and grounds.

amartinson

What year truck? Same thing happened on mine and the culprit was the cam position sensor. I believe that older trucks used a crank position sensor but mine was the cam sensor.

CoastalDav

Tach doing the windshield wiper and gauges going up and down, Crankshaft Position Sensor
in my truck.

Dave

jrs_dodge_diesel

When your tach quits, check the battery voltage (guage) and see if your A/C will come on. The computer controls the operation of the A/C compressor and the alternator. If the computer sees no signal from the CPS it will think that the engine is not running. It will therefore cut off the A/c compressor and alternator output completely.

mini14

CKP

mini14

CKP on 99 and below, CMP on 2000 and above

mulva

Hello everyone... I am new to the forum, and want to thank everyone for your help and advise in advance. Regarding the tach post, is this on a diesel or gas engine, I have the same problem on my diesel. Would it be the same thing, and if so, where would i find the cam or crank sensor?

Thanks again

amartinson

Yes, we are talking about diesels. I'm not sure on the 12 valves, but if they are like the early 24 valves, yours would be controlled by the crankshaft position sensor.

amartinson

Here is the location of the crankshaft position sensor on early 24 valves.

mulva

Thanks for the info. It will be a big help.

cumminsdriver635

Mulva: On your truck it will be on the front of the motor by the pulley on the crank with the balancer or whatever on it. Its kind of on the left side. Its no problem to change really. Cost me about $93 for mine. It will also cause the O/D and TC lockup in automatics to not work right, along with the alternator not charging. It also caused my speedometer to not work too.Good luck.

Eric

mulva

Ok, so i replaced the crank sensor, or as dodge refers to it, the engine speed sensor. anyway, still no change, I may not have the gap set correctly. Is there a set gap setting for this?
Thanks everyone.

cumminsdriver635

Yes there is a gap setting; but i just slid a piece of cardboard under the crank sensor and slid the sensor down not to tightly on top of it, then tightened up the bolts, pulled out the cardboard, and tried it. Worked good for me.

Eric

MnTom

Try using a match book cover (one layer).