Archived tach and a/c not working

[Hookemupman]

I just went out to drive truck and the a/c and tach are not working and it also seems that the charging system is not putting out any voltage more than the battery voltage. Thanks for any advice. Thanks Jason

 

[Phil Stuart]

Try checking the fuses in the.........

Power Distribution Center under the hood first.

Maybe others will chime in for ideas.



Phil

 

[Hookemupman]

I already check for blown fuses,and checked connection on crankshaft position sensor,when the sensor goes bad will it affect a/c charging and the tach all this happened at once?Is there a way to check the crankshaft sensor with a volmeter. Thanks Jason

 

[Phil Stuart]

Jason,



I wouldn't think the crank sensor would affect the A/C in any way But as far as the tach doing strange things...

probably so. You also said that the voltmeter was reading a low/no charging rate. Try checking the ground connections also. I have heard that a bad ground connection will cause some strange things to go on. Sorry, not sure how to check resistance of the CPS.



Phil

 

[dodgenstein]

I don't know about the 98's,but on my 93,the crankshaft sensor became unplugged and the A/C and charging system died. A/C has a cutout relay for high throttle inputs.

 

[danandamy]

If I recall right, there have been several instances of shorts occuring in the wiring inside the steering column. In fact, I believe that's what the high blow fan relay recall was to address partially too, the wires inside the column would heat up if the fan was on high for a long time and short out.



dan

 

[amsoilman]

Check the connections on the Engine RPM sensor near the front of the engine. Sometimes the wiring will rub on the engine and cause a short to ground and cause what you are describing. All the things you mentioned, as well as the cruise control will be effected if the engine sensor is not working correctly.

The plug on mine became loose and it caused the same things to happen.



Wayne

amsoilman

 

[Bill Lins]

Originally posted by danandme

If I recall right, there have been several instances of shorts occuring in the wiring inside the steering column. In fact, I believe that's what the high blow fan relay recall was to address partially too, the wires inside the column would heat up if the fan was on high for a long time and short out.



dan

dan, what year models does this recall apply to?

 

[danandamy]

Honestly Bill I don't recall exactly. I know it was on 12valve trucks just don't recall if it was all 12 valve year models. I had the recall done on my wife's 95, the dealership managed to break part of the overhead console I got the recall notice on my 95 and never took it in, just couldn't bear to let them touch it so I don't run the fan on hi too long LOL



dan

 

[Reb.B]

its the PCM. the voltage regulator in the truck is in the PCM. pcm controls, a/c clutch, overdrive and shifting in autos, tach. I,m positive. get a buddies PCM is a 98 truck (must be 98 because 98 is the only year with digital dash and 12 v) and see if everything works.

 

[rhoads]

no tasch./chasrging

asorry key boasrd ascrewing up~!~!

Fuase pasnel; l;eft end of dasash as i recasl;l; 5 or `15 amp bl;owen fuase wil;l; casuase the asasme thing. /. /

Moast owner find thias asfter repl;ascing al;t. /

 

[Phil Stuart]

Re: no tasch./chasrging

Originally posted by tdramrmbr

asorry key boasrd ascrewing up~!~!

Fuase pasnel; l;eft end of dasash as i recasl;l; 5 or `15 amp bl;owen fuase wil;l; casuase the asasme thing. /. /

Moast owner find thias asfter repl;ascing al;t. /

Whoaaaa!! Man!



Phil

 

[Hookemupman]

Thanks for all the suggestions it ended up being the speed sensor was bad, everythings back to normal now.