2000 Olds Bravada problem

My 2000 Olds Bravada wouldn't crank. There was 12V present on one of the coil terminals with the key on. There is a small module next to the coil with a 4 terminal plug. It
looks like it's on a heat sink with silicone grease. I don't know if this is an ignition module but it also had 12V on one of the terminals as well with the key on. I checked all the fuses relating to "ignition" and swapped the starter relay in the fuse box in the engine compartment with another of the same type but it made no difference. When you turned the key to start there was a soft "click" sound like a relay, which seemed to come from under the dash on the passenger side. Don't know what this is. The starter is oriented so that the solenoid switch is inaccessible and therefore it's impossible to get a meter onto the coil terminal. I removed the two bolts holding the starter, (this is the smallest starter I've ever seen on a car, so at least it's light), and I was able to turn it a small amount but the wires are so short and up on top I still couldn't get a meter on it. And of cours e I didn't want to try to crank it while it was hanging. That could have been a real disaster if it just decided to crank. So I thought that I'd have to remove it to test the solenoid coil wire and then bench test the starter as well, but I wasn't sure if I could have gotten these wires off. I was really stumped until I called my son.
Mike came over to take a different look at this thing and he realized that you get to the starter terminals by lifting the rubber flap in the wheel well. I remounted the starter and we monitored the coil terminal on the solenoid while holding the key on, and it was dead. So while I was going to get a small alarm battery to put 12V on the coil to see if it would energize. Mike double checked the fuses. I heard him say: "Dad, I thought you said that you checked the fuses"? Well I did check everything that mentioned "ignition," overlooking the 10 amp fuse that said "crank". That fuse had opened up and it appears for no reason. I haven't measured the current through that new "crank" fuse but since replacing it the car has been started at least 20 times without a problem. So I get the dummy of the month award for sure. But it does beg the question what opened that fuse?
Now I know from dealing with high inrush current circuits in some TV sets that we'll sometimes find an open fuse for apparently no reason. The theory is that repeated heavy instantaneous loads will sometimes weaken a fuse element and then it may fail as in this case for no apparent reason.
Well I thought that this was what might have happened until my wife called me from a supermarket parking lot the other day where she was stranded with apparently the same symptoms. I picked up a box of 10 amp fuses along the way and upon arriving found a blown crank fuse again. With a new fuse the car started right up and has been OK for two days now.
I have asked her to describe the symptoms and the events leading up to them exactly as she remembers them each time this has happened. She tells me that in each instance there was no sound from the starter. Apparently not even a momentary attempt to crank when the key was turned. That suggests to me that what took these fuses out was a dead short between the ignition switch (output) and the solenoid wire in each case that the key was turned. The problem is that it seems to be an intermittent dead short. I have no wiring diagram for the car but I’m thinking that 12V must go from the 12V bus, through this 10 amp crank fuse, through the ignition switch, then possibly through a relay, and then to the solenoid terminal on the starter. So if that is correct then p erhaps the problem is a chafed wire that could be anywhere beyond the ignit ion switch (output).
For the time being I’ve showed her how to change the fuse in a pinch, but naturally I have to fix this. I’m almost ready to wire a starter button with a separate ten amp fuse from the battery right to the solenoid. I know about neutral safety switch concerns and so naturally I’ d rather not have to but I’m not sure how to find this otherwise.
Can someone please take a look at the schematic if they have it available a nd please tell me if I’m correct in my guess as to how the starting circu it is actually configured? And if you have any other ideas I’d appreciate your input. Thanks for any assistance, Lenny
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snipped-for-privacy@gmail.com wrote:

SNIP

Thanks for any assistance, Lenny
The click you hear when you turn the key is the fuel pump relay.
As for the power path.-
Power from Ign C fuse(20A) goes to ignition switch. Start term of ignition feeds out to the underhood 10A crank fuse. Crank fuse then goes into the Park/Neutral switch via a PURPLE wire. out of P/N switch via a PURPLE w/White stripe to the starter relay (underhood fuse block) Through the starter relay to ground.
I would pull the under hood block loose and look under it to see if any wires are chewed/chaffed.
--
Steve W.

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Steve W. wrote:

Agreed, and to add: assuming its 4wd, the CRANK fuse doesn't just go to the PNP switch it also goes to the Transfer Case Shift Control Module, which is behind the right kick panel. (PPL wire also)
Good luck! GW
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Geoff Welsh wrote:

Bravadas are AWD. No selector for the T-Case.
--
Steve W.

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Steve W. wrote:

ahh. so the "ESTC 4wd only" on the diag. applies to the Bravada. 10-4
GW
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Geoff Welsh wrote:

It still has it BUT it's not connected the same in the 2000s. It basically uses 2 speed sensors to decide if the front/rear power is equal. If not it activates a clutch pack to the front.
--
Steve W.

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Steve W. wrote:

I pulled-up a 2000 diagram, but without the guy's RPO sticker at hand, I had to guess (incorrectly) that the Bravada, would indeed have ESTC, not the NOT-selectable (automatic) TC you described.
On a completely unrelated note....had a Ranger that wouldn't crank recently....after various other problems were rectified (dead battery etc) I also realized that the owners "friend" had tried randomly swapping relays around and had PUSHED the WIRES right out the back of the relay box (on the stater relay slots.),
Its 2013....stop asking your "friends" to help, and call the tow truck first. GW
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Geoff Welsh wrote:

That's one of the "fun" items with the Bravada. That same system is what they installed on the Trailblazers with the "Auto" 4X4 BS. The ones that eat the clutches out real quick because folks leave the auto mode on.
Yep, most of the new stuff requires a bit more than shade tree knowledge to repair, and as the keep adding more crap it will just get worse...
--
Steve W.

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On Saturday, October 26, 2013 3:35:29 PM UTC-4, snipped-for-privacy@gmail.com wrot e:

rse I

a real

. I was really stumped until I called my son.

nd then to the solenoid terminal on the starter. So if that is correct then perhaps the problem is a chafed wire that could be anywhere beyond the ign ition

’d rather not have to but I’m not sure how to find this otherwise.

and please tell me if I’m correct in my guess as to how the starting cir cuit is actually configured? And if you have any other ideas I’d apprecia te your input. Thanks for any assistance,

So worst case if I can't find this problem what if I pull the crank fuse an d run a new wire from the battery through a 10 amp fuse and then through a suitable momentary NO switch right to the solenoid. I don't care about neut ral safety. I would think that would run the starter, and with the key on t he car should start, right? Will that hurt anything? Lenny
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snipped-for-privacy@gmail.com wrote:

You can bypass the P/N switch right in the fuse block. If you got the wiring diagram I sent to you you can see that the start relay and the crank fuse are in the same under hood block. Just run a jumper from the fuse output to the start relays activating terminal.
I would really check the wiring under the block first though. More than once I have found problems from mouse damage or even sharp hardware causing trouble.
--
Steve W.

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On Sunday, October 27, 2013 9:25:44 PM UTC-5, Steve W. wrote:

Squirrels can eat up the wiring and also vacuum hoses. A guy used to have his 35 feet long motorhome parked in his back yard. Squirrels chewed on some of the vacuum hoses.
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On Saturday, October 26, 2013 3:35:29 PM UTC-4, snipped-for-privacy@gmail.com wrot e:

rse I

a real

. I was really stumped until I called my son.

nd then to the solenoid terminal on the starter. So if that is correct then perhaps the problem is a chafed wire that could be anywhere beyond the ign ition

’d rather not have to but I’m not sure how to find this otherwise.

and please tell me if I’m correct in my guess as to how the starting cir cuit is actually configured? And if you have any other ideas I’d apprecia te your input. Thanks for any assistance,

I will pull that fuse block as soon as my wife gets home, that is if I don' t have to go out and rescue her again that is. Thanks, Lenny
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On Saturday, October 26, 2013 3:35:29 PM UTC-4, snipped-for-privacy@gmail.com wrot e:

rse I

a real

. I was really stumped until I called my son.

nd then to the solenoid terminal on the starter. So if that is correct then perhaps the problem is a chafed wire that could be anywhere beyond the ign ition

’d rather not have to but I’m not sure how to find this otherwise.

and please tell me if I’m correct in my guess as to how the starting cir cuit is actually configured? And if you have any other ideas I’d apprecia te your input. Thanks for any assistance,

Steve I can't seem to contact you through email anymore so I hope you see this.
I just got your email with the diagram Steve. Thanks so much for sending that. Now I can see the whole picture of what's going on. I almost wish this was a constant dead short. It was fine all day yesterday and my wife just called me a little while ago to let me know that she had to replace another fuse. Damn problem is so sporadic. It doesn't seem like it would be a piece of hardware. Rather as you suggested it seems more like a wire, somewhere. This diagram will help a lot. Lenny
I haven't gotten a chance to troubleshoot this today, however I've been lo oking at the schematic and it seems like with the key on to ignition positi on, if I were to short, (through a 10 amp fuse) terminals 30 to 85 on the s tart relay, that should run the starter and start the car, right?
Lenny
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replying to captainvideo462009, Juma wrote: did you ever figure out what was the cause for you battery to be drained on your Bravada and you ever get it fixed? please let me knowbecause I'm haveing the same problems. thank you
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Mine is doing the same thing. Hopefully this helps. thoguh when mine wouldnt start, for awhile tapping on the fuse box and starter relay would coax it to start.
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