gremlins in my denali!!

[frank w]

my '99 denali is having electrical problems & i've had no luck with them. the oil pressure guage shows 40 plus when cold, but when it warms up, it will drop down to near zero at idle & 20 at hwy speed. i have replaced the sending unit twice, put in a new cluster (the fuel guage was acting up also), had a new oil pump & screen installed & it still does it. the engine is quiet at start-up & when the guage is reading low. no oil usage, smoking etc.

the other problem is that the radio display, wipers & power windows all quit working at the same time intermittently. usually they start working again quickly, but every now & then they won't work again until it has been shut off for awhile.

if anyone has any ideas, please let me know before i decide to get rid of it & i really don't want to do that!!

thanks
frank

 

[99FLtahoe]

my next place to look might be the bcm (body control module) it might be a gound or power short. Only real reason for thinking ^ is that you have replaced all the oil stuff. Now that is not to say you did not get a bad OP or OPSU but with the other glitches you said also leads me to the BCM or somthing related

 

[frank w]

my next place to look might be the bcm (body control module) it might be a gound or power short. Only real reason for thinking ^ is that you have replaced all the oil stuff. Now that is not to say you did not get a bad OP or OPSU but with the other glitches you said also leads me to the BCM or somthing related

hmmm, could be. i'll give it good checking over. i never considered that the new oil pump could be bad.
thanks for the input!!

 

[99FLtahoe]

oh NEVER take "new" parts for granted, i was working at a shop 2-3yrs ago and had a 2003 ISH hundyi elantra come in with a dead alt. well i changed it out, load tested it, did amp draw, and other minor test and it passed. well i get a call 24hrs later car had a dead battery. ok so i check it out agian and well ALT died, long story i used 4 diff alts from 2 diff suppliers till i finally got one that stuck and worked.

you would really need to find ,a way to test the OP that the pump is putting out, now i have no idea how to tell ya to do that as i never PERSONALLY done it. on the BCM you are goint to first want to try and see if there is any undue current draw on the BCM via a milliamp reading from ground lead at bcm and to a real ground and i think you can do the same on the power side of the bcm, make sure it is the MAIN (+) and (-) of the bcm not a source leaving the bcm. it deff sounds like a bcm prob to me as it is effecting multiple bcm accesories

i would try a few "junk yard" OPSU first before you try a op if you choose to also go that route. but i belive those things are prob good working order. It deff sounds eleect to me