1999 Suburban Electrical & Start Problems

[bretcopsey]

I have a 1999 2500 4x4 that has had some problems lately. I'll start from the beginning to hopefully help narrow this down. Many months ago I heard a "clicking" under the dash that coincided with the interior light coming on and off. I culdn't immediately figure it out and simply pulled the light fuse. The lights quit coming on but occassionally it would sound like a midget was tapping out morse code under the dash!

A few weeks goes by then I start having starting issues. I ended up replacing the starter solenoid and at the same time I removed a remote start system that had been installed by a PO. I didn't have any of the necessary remotes, documentation etc to use it anyway and figured it could be contributing to the problem. I had hoped that this was the source of the "clicking."



The truck started fine again, and I also had interior lights functioning as they should. But soon after the keyless entry remote no longer worked, and the interior lights didn't function properly-this time not coming on with the door being opened??

Then, I noticed what sounded like an A/C compressor bearing going bad upon initial startup, but not every time. I finally realized that the noise was coming from the starter not disengaging.

Today I replaced the starter. I had a somewhat drained battery so I had it charged-it's only a few months old.

I went to hook everything back up, and decided to try a trick that was mentioned in another post on this board. I connected the positve cable, and connected a test light to the negative cable and negative battery post. The light came on and based upon the other post this is indicative of an open circuit.

I pulled every fuse in the dash, one at a time, and the test light remained on. I then did the same on the under hood fuse panel. Pulling the horn fuse made the test light dim, but it never went completely out. Then all of a sudden I heard that "clicking" again under the dash. I didn't find a midget so I started poking around I found what I am guessing to be the body control computer making the noise. I placed a couple fingers on the side of the "box" and could feel that it was the culprit.

Is this "box" controlled by a relay somewhere, or could the "box" itself be bad???

[Beegs]

I have a 99 Yukon, it makes that clicking sound only when the battery is low.

[HILROD]

My old boss had that problem which I had to fix. It's been a while, it seems like there were no door switches, but the door latches activate the dome light. There is either a short in the swithes or wiring for the dome lights. I wish I could remember better, but I'm sure the latch was changed. FRANK

[HILROD]

Sorry double post.

[bretcopsey]

My old boss had that problem which I had to fix. It's been a while, it seems like there were no door switches, but the door latches activate the dome light. There is either a short in the swithes or wiring for the dome lights. I wish I could remember better, but I'm sure the latch was changed. FRANK

Above you said "no door switches..." could you elaborate a little? The Suburban does have a typical "plunger" type switch in the dash that is triggerd by the door opening. This switch controls the dome. Do you think I should look there first?

[HILROD]

If the truck has normal door switches, chech those and there wiring. Also sometimes the switches get adjusted in too far, mostly from loose hinges, and need replaced. The tahoe,(might have been a caddy?), I think the door handle activated the dome lights also. FRANK

[6'9"Witha69]

There were various GM models which turned on the dome light when the handle was lifted/pulled regardless of whether you opened the door.

[bretcopsey]

Appreciate the feedback guys! Hopefully I can isolate this d*mn drain and get the thing back on the road!! Hopefully I'll be posting back later tonight with some good news!

[ZZ430]

I worked on a 96 'burb and I've heard the BCM clicking before. It happened at idle with a lot of accessories on and underdrive pulleys in this case. Headlights on, heater etc.

If the system is under 12 volts while running it will do that.

[tumper93]

When you checked for a parasitic load with a test light or meter you have to wait for up to 10 minutes for all the modules to go to sleep! If you have onstar then the light will get bright every 7-minutes I believe it is and then go back out. Trying to determine if you have a draw with a test light on a newer vehicle is a bad way to do it because you don't know what the resistance value of the bulb and wiring to it is. You need to put an ammeter and check to see if it is below 32ma after everything goes to sleep. Test lights can be all different amounts of resistance from one to another and cannot be trusted and can mislead you to a problem because of that low resistance in one as to another. We have had a lot of problems with BCM's around that time period, more in W bodies than trucks but I have had more than a few in trucks also. The clicking is most likely a faulty internal relay of the bcm, the draw may be within limits but could also be caused by the bcm. If you have to replace the bcm you must have it programmed after it is installed, most of the time based on the build your vehicle may not start after it is replaced because of the passkey theft deterent system. I would suggest taking it to the dealership and let a tech diagnose it. Are you near High Point, NC? If you are I can give you the address to the dealership I am at and we can see what is going on.

[bretcopsey]

When you checked for a parasitic load with a test light or meter you have to wait for up to 10 minutes for all the modules to go to sleep! If you have onstar then the light will get bright every 7-minutes I believe it is and then go back out. Trying to determine if you have a draw with a test light on a newer vehicle is a bad way to do it because you don't know what the resistance value of the bulb and wiring to it is. You need to put an ammeter and check to see if it is below 32ma after everything goes to sleep. Test lights can be all different amounts of resistance from one to another and cannot be trusted and can mislead you to a problem because of that low resistance in one as to another. We have had a lot of problems with BCM's around that time period, more in W bodies than trucks but I have had more than a few in trucks also. The clicking is most likely a faulty internal relay of the bcm, the draw may be within limits but could also be caused by the bcm. If you have to replace the bcm you must have it programmed after it is installed, most of the time based on the build your vehicle may not start after it is replaced because of the passkey theft deterent system. I would suggest taking it to the dealership and let a tech diagnose it. Are you near High Point, NC? If you are I can give you the address to the dealership I am at and we can see what is going on.

Good to know! The test light is about all I have at my disposal besides the volt guage on the dash. If I could get the darn thing to start I'd be happy. I just hate the thought of adding a tow to the cost of taking it to a shop! I'd also take you up on your offer, but I'm in SW Ohio.

I did just remeber that the heater switch was acting up recently as well...HMMMM

[bretcopsey]

I've not had much time to look at this lately, but just spent some time tonight and I'm starting to feel like I'm up the creek here!!

The battery was re-tested tonight just to be sure-it's only a few months old. The new starter didn't make any difference. I hit the key and the volt guage on the dash reads about 10.5 volts, you can hear the starter solenoid click and that's it. Same place I was when this all began. What really has me puzzled is that this all started with a radiator repair. I rer-installed the radiator and filed with coolant. Started the engine and bled out the air. There was a brief spark at the positive terminal, but I didn't think anything of it at the time. I shut it off and went to start it again two days later, nothing-where I still am today.

I'm thinking about replacing the battery cables, but would hate to go through the effort with no results. I'm also wondering about the current setup, which I will post some pictures of shortly.

[bretcopsey]

Here are some pictures of the current battery cable situation. It looks to be aftermarket, possibly part of the remote start system I removed?

There are two cables at the positive terminal. Onegoes to the starter, one to the terminal mounted on the fan shroud. Then thee is a cable that runs from that same terminal on the fan shrous to the alt. The other terminal's cable runs over to the rear of the underhood fuse box that's near the brake booster.

[CamaroAJ]

i can see the problem in the first picture. ohm the battery cable and see what it says, if it were me i would be replacing the cables.

[MrQuick]

also turn your headlights on and wiggle that positive terminal. see if anything changes. but i agree with AJ, replace that cable...there are 3 places for failure in that picture alone.

[bretcopsey]

i can see the problem in the first picture. ohm the battery cable and see what it says, if it were me i would be replacing the cables.

That's what my gut is telling me. The only question about that job is whether I should route everythng as it is now? I have no idea what purpose the"junction block" in the second pic serves. It has a "fuse" rated at 175 amps.

If that is not factory, I'd like to eliminate it as a possible source of the problem. Trouble is, I'm not sure how everything needs to be routed if it does come out.

Thanks for the help guys!!

[bretcopsey]

Found something that resembles the fuse on my fan shroud.

http://www.littelfuse.com/cgi-bin/r....ION=gZriRg8Ucy

[CamaroAJ]

its factory leave it there. but the one side does look like its missing a nut to hold the cable on so check that out.

[bretcopsey]

All this for bad battery cables!!

Why is it that the simple things can get you so bad sometimes?

Oh well, it's fixed now. Thanks guys!!

[MrQuick]

the basics will kick your ass daily. Some guy sold a perfectly good 2000 camaro cause of a bad positive battery side mount terminal. good for me I suppose?