Issues with 4wd, cruise control, radio 1998 chevrolet Blazer 4wd

stevekruzichstevekruzich Member Posts: 33
edited August 2017 in Chevrolet
Its a 1998 Chevrolet blazer 4wd.

Ok i had another thread where i had a NO SPARK but cranks condition. That has been solved but now i am trying to fix the other things the students at the local college broke.

My brain is mush lately and I am running in circles trying to fix them.

First of all i cannot find a schematic for the wiring on the transfercase, 4wd buttonns and tccm. It eludes me.
Secondly the cruise control stopped working after they did this, and cannot find a schematic for the cruise control circuit to trace where it might be broken.

third the radio is a mystery. IT won't work if its cold. It does work when the inside of the car gets hot sometimes. The clock on the radio went out too but periodically it will flash when i turn the ignition.
I cannot find a reason for this. The other thing is that only one speaker works on the radio and i checked the wiring to the other speakers.

First things first. I neeeeeed to find out why my 4wd buttons do not light up. The car is stuck in 4-high and i need to get it out so i don't burn up my money on gas.

The cruise is kinda important to me as i live a hour away from any town and my legs hurt all the time from diabetes. Takes the strain off them

I need a schematic for all this if its available and some direction on where to start and end on the tracing of the problem. I dont' want to have to spend money on parts to see if that fixes it. I'm broke. This engine swap has already cost me over 500 dollars in parts and some labor and I'm running out of money.


  • thecardoc3thecardoc3 Member Posts: 5,600
    Hi Steve. Let's take this a couple steps at a time. First if you don't need the 4WD an easy trick will be to pull the motor off of the transfer case and shift it by hand. That will save you some money until such a time when you can address the problem correctly. You are going to need more than just a schematic for the systems that are down. Much of the diagnostics are done with a scan tool and I wouldn't even bother trying with anything less than the GM Tech II.

    Did you try looking for schematics here? .....

  • stevekruzichstevekruzich Member Posts: 33
    Hi Cardoc. Yeah I don't have scantool. This irritates me because it was all working prior to me taking it to the school to get the engine swapped. :(

    I was trying to avoid going under and manually shifting it. I'm more afraid of shifting it too far, as i don't remember if I can even turn the cog too far.

    I guess i will get under there today or tomorrow and do that. Get it over with.

    I will look at the site you gave.
    I'll post what i do find.
  • thecardoc3thecardoc3 Member Posts: 5,600

    Hi Cardoc. Yeah I don't have scantool. This irritates me because it was all working prior to me taking it to the school to get the engine swapped. :(

    Maybe these issues are related to the engine replacement and maybe they are not. Either way the most efficient way to solve each of the problems starts with forgetting what has been done in the past and just troubleshoot what is going on right now. Pick one of the issues to solve and work through it completely. Once that one is handled, then choose the next one to address. Any other approach makes the work harder instead of easier.
  • stevekruzichstevekruzich Member Posts: 33
    I got the service manuals for this year and car, and have been tracing the circuits. I think my first stop is G105 which should be the ground connection at the back of the left head on the engine. It seems that all the circuits i mentioned ground at this point and through a splice pack. I know its connected but i am going to have to get me a mirror or something so i can take a peek behind the motor to see if a wire is dangling. We'll see.
  • thecardoc3thecardoc3 Member Posts: 5,600
    edited August 2017
    "Checking the ground" doesn't mean looking at it or touching it. Checking the ground means when you attempt to turn the circuit on, measure the voltage drop from the component ground connection to the battery negative post. No, or a very low voltage drop (under .2v) is a good ground. You don't have to try to inspect or do anything else with that circuit if this check passes. If the wire is broken and hanging you will measure a large voltage drop (anything over 1v more than likely you would see 11v or higher).
  • stevekruzichstevekruzich Member Posts: 33
    Well i get to check the wiring real good behind the motor. Damn trasmission went out. was rolling towards eureka and all gears just quit. I am guessing oil pump went out on it. Got it home and as soon as i am over this somach bug i'll be pulling it and the transfer case. I'll check each wire going there and all the ground wires to make sure all are hooked up and have the right ohm values.
    I think i will just buy me a soldering iron and fix the cut wires that were done when they swapped the engines and do the wire repairs right.

    Just am hoping that this wont be too costly. Its about closer to winter and i can't work on vehicles in the cold. My body just won't do that anymore
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