I have a 97 blazer 4X4 that has started giving me fits. Anything from a stuck key to limp mode transmission. IT has a "tick" in the fuel gauge when the turn signal is on or when I hit the brakes. Sometimes the passenger window control wont work as-well-as the rear hatch button. suddenly has multiple sensor codes, oxy, MAP, and Mass air. have had the tranny rebuilt. works sometimes other times it is in limp mode. have replaced the catalytic converter. I have even chased vacuum lines to every where it seems like and replaced the cruddy and cracked ones. performance at times is horrible like it wont pull itself, other times runs like there is no tomorrow. Got an ignition switch gonna see if that might be the answer. seems as though all issuses could stem from there. Other than that I might be looking for a Dynamite Man. If you have any other ideas let me know please. have a great day.

 

Have you tried disconnecting the battery for a half hour or so then reconnect it & see what happens.

 

Yes I have. even disconnected the computer for a while. Doing this made no noticeable change with the exception for the first couple stop-n-go's. I figured it was the computer adjusting. However she ended up back where she was.

 

Update, ignition switch is in and, crossing my fingers, first two test drives she is ready to run! Test drives were just around town for about three miles, but there are several stops.

 

After listening to your laundry list of troubles, my first thought is that you have some kind of electrical problem. Especially the dash/gauge issues. Either a harness got pinched/melted somewhere or maybe some water has infiltrated the wiring (connector). The tough part is tracking this down. It is possible that you have multiple issues that confuse the situation.

A couple of years ago I had issues with my turn signals working intermittantly, and it ended up being the multi-function turn-signal, cruise, wiper, highbeam switch assembly in the steering column (!! $130 !!). I would check locations common to the majority of the symptoms. Places like the main fuse blocks (under hood and by A column).

Concerning the stuck key, I would say go ahead and replace the ignition switch. At the least, it's going to fix at least one problem. There could even be a worn/defective switch inside that's not providing adequate power to circuits downstream. I'll bet is isn't cheap though and means having separate ignition/door keys. Are any special tools needed to get that out of the column?

The window issue sounds like a power distribution problem. It could just be related to the switch on the door. Does the problem happend with both door switches, or just the driver's side? If both, start at window motor and see if your voltages are good. You should have at least 12.5VDC. Anything less should lead you to a bad relay/switch/wiring. If it stays with one switch only, then look into replacing that switch. Several years ago I wanted to replace the burned out bulbs in my driver's door switch assembly. The local dealer says the bulbs are NOT avaliable and wants to sell me a $400 switch assembly. I suggested what they could do with with their switch assembly.

As far as the sensor codes go, I don't know enough to say for sure that your issues involve a defective ECM or BC. What it sounds like is that at least one of the modules is getting erroneous or defective information/signals, and this would lead me back to what I said in my first paragraph about damaged wiring. Maybe someone with more intimate knowledge of what connections there are between the various onboard computers could shed some light on this.

Good Luck, and keep us posted.

 

still going strong. Shift from 1st to 2nd is a little high on rpms but at least she is shifting on her own again.

 

The ignition switch can cause a host of weird problems. It sounds like it was the cause of yours. Glad it was something rather easy & inexpensive relative to what else it could have been!

 

Well to tell you the truth (swartlkk), it is too lat to not be expensive. See, I got the tranny rebuilt, with all new solenoids of course. Put on a neutral safety switch, just because the old one was REALLY difficult to disconnect. The ignition switch itself was a little over a hundred. The biggest expense by far though was the poor fuel economy. Found out today the wife, bless her heart was making my funeral arrangements, she said I was totally consumed. I suppose I was, however the ol Blazer is hers, figured there was extra reason to do the very best I could, you know with wives the better you do the more that goes on the rewards card.
It certainly has been an adventure, and I am sure glad I found this Forum. Thank you for all the help.

 

Shoot.. Missed that part of your original post. Hopefully that was necessary and not just another mis-diagnosis of a failing ignition switch.

 

It is still "so far so good", approx. 1000 miles later. YEA!