Multiple electrical issues (big surprise) assistance – blazer forum – chevy blazer forums gas constant for helium


• The second issue I knew of beforehand, the gauge cluster had issues. It had the stepper motor issue (which has since been corrected by someone who had a service). 9gag It also had issues with the odometer/trip display which I initially thought was perhaps a soldering issue. I have not gotten into the dash to verify just yet (wasn’t a big concern, but now it may be) but now I am thinking it may be a bit more. It used to either be on and display fine or it would be just off. Now I am seeing anything from it having just a random number anywhere in the display pop up with nothing else or all options lit up at once or display correctly, or just the KM will be showing.

• I have now also found that the fog lights are not working. I only had a quick minute to troubleshoot this but I was able to verify the under hood fuse is good, and tried another just in case. I swapped the horn relay for the fog light to test and still it does not work. The bulbs looked good, but did not directly test these with a battery. I did do a voltage test at the fuse and was only getting .24v.

• I cleaned the MAF and throttle body ( TB was left on the motor and yes I hand;t read before that I shouldn’t have moved the butterfly manual. I drove the truck home (25 miles) with no engine light but did notice it would lurch coming to a stop and down shifting and would be almost like it had cruise control on at lower speeds. Started it this morning and instantly got the engine light, pulled the code to be P0507. I have been driving around all day seeing if it will relearn and clear on its own with no luck. electricity distribution network I just did the detach battery and 3 brake pedal presses oddly enough has worked to clear but I haven’t yet tested the idle or driven yet.

• Perhaps the biggest issue I am having is I cannot get the secondary air smog system to complete its test in the scan tool so i can get it smogged. I have had many cold starts, GM drive cycles, driven 2 tanks of gas and it still remains. Not sure if this is on its own per perhaps part of all these issues I am starting to think is a BCM issue.

• The best I can tell, from the intermittent trip counter working. I am getting about 12-13mpg in this thing. I knew it would be lower, even figured getting that lower end EPA estimate of 16mpg even on the freeway, but this is a bit crazy, might as well have gotten a suburban. gas kush New air filter in.. and I have new wires and plugs to put in, and and oil change to do but hopes are low. side note could anyone point me to a thread on tips on plug changes? I saw one before regard may be needing to remove a tire to get to a tough plug but can’t find it now.

I’ve been investigating how to create an override circuit for the daytime-running-lights/auto-headlights and in the process found that very many of these things (definitely all of the lighting) are run through the body-control module (BCM). So I think your suspicions could be correct. Have you tried disconnecting the electrical connectors for the BCM and underhood fuse block? There is also the Body Relay Block (BRB) that has a bunch of relays on it.

I’ve attached scans of some of the schematics I’ve created from my hard-copy service manual I purchased off of eBay. Perhaps these will help with #1, #3, or #6.Awesome, thank you very much for the schematics! I haven’t made my way to the BCM as I was slowly uncovering these other issues as I drive it and or troubleshoot others. I will have to find it and the other items and play with those as well to see what I can get.

I bought new Throttle position sensor, new IAC and a new TB gasket. electricity electricity goodness I took off the TB and ran it few a few cleaning cycles in my sonic cleaner and put all the new parts back on and am still getting the high idle code popping back up after clearing the codes and driving. To make it worse, after all these parts and getting the same code I then got a code, for an O2 sensor out of spec. I forgot to take a screen shot of the code number before clearing and trying the drive cycle again but I have the detailed test results below. Not sure how changing these new parts would then trigger O2 issues, but sounds like I fix something the next weakest thing goes haha. I may have to start a smog specific thread I suppose but if anyone is familiar with $06 codes let me know what you think.

Just to throw it out there: On the 92 Blazer I used to have I kept getting an O2 sensor error so I dutifully replaced it only to have the error eventually come back. What turned out to be the problem was that my fuel injection spider was leaking, dumping raw fuel into the engine causing an over-rich condition that fouled the O2 sensor. I mention this as a reminder, if you have not done so already, to keep in mind that sometimes the symptoms are indicative of a larger fault rather the thing reporting the fault. Funny you should mention exactly that. I ran across a post regarding the SCPI to MPFI upgrade on a silverado and made me want see if I could do it to the jimmy. But whether I can or cannot it made me wonder if it was the fuel efficiency issue on this truck even with it’s lower miles. I was waiting to get back to my computer to post these pictures I took while the TB was off and noticed the distinctively clean side.

If that is the case, I still wonder why it would clear all tests (except the secondary air) until cleaned the TB..then throw the high idle code, then the O2 code after I get the TPS and IAC replaced. I suppose the IAC could have been stuck more open and compensating a bit for the over injection of fuel witht he extra air then drop the airflow with the working IAC…. but I digress: I assume at least to 2 clean ones I can see are cleaned by the gas or stuck or leaking.. electricity year invented Is it possible to do a MPFI swap on this 2000 jimmy?