1997 Suburban Electical Cut Off

I have a 97 Burb with a strange problem. With no regularity, all the electrical will shut off for a split second. The motor of course jumps because of a temp. loss of power and all the dash lights come on and the radio flickers, etc. It is exactly like if you would turn the key off then on real fast. All the normal system checks perform again as if you were just starting the truck. Occasionally, it will cut out long enough to stall and will have trouble starting. I had the fuel pump/relay replaced 6 months ago and I know that these symptoms sound similar to that, but the total electrical cut off part does not fit. It must be something else. I have eliminated a bad ground problem by installing new grounds from battery to frame and battery to engine. That didn't do a thing. I have noticed though that it will occur more often when going over potholes or speedbumps and when turning. Maybe something is loose, but what? I have considered a faulty ignition switch which could fit these symptoms, but I hate to keep burning $$ in trial and error. Can anyone help???

You might try checking the connections on the alternator, one of the connections usually powers the ignition and a lot of other stuff. Also, check the hot wire from the battery to the alternator. Most of the time they are connected at the same point on the alternator.
Best,
tomic

pull your both battary cables and clean them good

My wifes car is doing something similar and I am sure that it is the ignition switch (which I haven't replaced yet). A mechanic buddy of mine helped diagnose it by simply asking me "does she have a bunch of crap on her key ring?" Of course she "did", and that wear and tear messed it up. A quick jiggle of the key clears it up, but replacement is next on the list.

I recently had the transmission dip stick tube break and had it replaced. Just after that my Burb would die when it felt like it. On the road I discovered that there is a ground wire that goes under the tube mounting bracket that was never tightened. Once tightened properly I have never had the problem again. Good Luck