96 Blazer no power to interior, starter, nothing!!!

[dmorlow]

Problem started because my wife's car was having some alternator issues. Her car wouldn't start and her battery was bone dead. I took the alternator and battery out and brought it to Autozone to have them test both. They diagnosed the alternator as bad and the battery was good. I bought a new alternator and had them charge my battery again. Now, I know I made a huge mistake when reinstalling the parts. I installed the battery first (which I know now is wrong.) When I hooked up the alternator, I was tightening the positive lead when the wrench touched some metal and sparked. It was a quick spark. I got everything in and went to start the car when I noticed the car has no power at all with a newly charged battery.

I brought my car over to my dad's house where he has a hoist. Took off the passenger front wheel, took out all of the wheel well. Took the battery out, the coolant bottle and freed up that area of the car so I can see everything. Called the dealer and asked them for advice. They said I need to check the inline fuse for the starter. They said it looks like a piece of hose over the wire but it's really an inline fuse on the purple wire. They said it's about 6 inches from the starter and about one inch long. He said this wire is the wire that feeds power to all interior electronics. I told him I couldn't find it and he confirmed it's there. We first tried splicing into the wire in a few spots to figure out when the key is on or turned over, if there's any power going to the purple wire. There was no voltage anywhere in the wire. One guy I had come over to see if he had any ideas, he took a test light and hooked it up to the positive wire and then touched it to the purple wire and then found the test light luminated. He said that wasn't right because that means that the wire is grounding out.

The next thing we did was take all the wiring where the purple wire rides out of the harnesses from the starter to the firewall. We traced the wire by hand and followed it from the starter to the firewall and found no splices, shorts, melting, or anything along the whole wire. We also confirmed there is no inline fuse on the wire anywhere. We followed it up to the Bosch relays on the firewall. He was assuming one of the Bosch relays were bad. We removed the one that the purple wire went to and checked it for power. We hooked one side of the test light to ground and checked every single lead in the Boshe relay's socket for power and nothing has power there.

It made sense to me if there was no power earlier in the wire, there would be no power at the firewall because the power is traveling in that direction, but I had a tech that's been working on cars for 20+ years helping me (I never met the guy before but had a close friend of the family that said he's a genius on cars.)

But then he went back to where I was suspecting. Some reason, when you short the two leads at the starter silenoid, the car does turn over. But the key doesn't turn it over (nor any electrical in the car works), which means either the silenoid is bad, or whatever triggers the silenoid to short the two leads is bad. He says to replace the silenoid and also take the starter in and have it tested.

My dad says that's not the problem and he's convinced there's a bad fuse in the car somewhere. Unless the fuse is behind the dash in the ignition, I don't know where to find it. Also, we've been wordering if the ECM is fried, or needs to be reset, but I'm very hesitant to mess with that. I didn't unplug it the whole time. I know there's special resetting procedures or reprogramming, but I'm not sure if that would fix anything. I've never worked on electrical in a car before yesterday and I've learned more about starters than I ever wanted to learn yesterday, but obviously I'm still missing something. Any suggestions on what to look for why no electrical stuff works in the car?

[DelCoch]

Originally Posted by dmorlow

. . . When I hooked up the alternator, I was tightening the positive lead when the wrench touched some metal and sparked. . . . he took a test light and hooked it up to the positive wire and then touched it to the purple wire and then found the test light luminated. He said that wasn't right because that means that the wire is grounding out. . . .

If I understand you right, your purple wire runs from the starter to the firewall and powers the accessories. Right? If this is the case, when you put your test light on the purple wire, which has no power to it, the test light is supplying current to the accessories. Not enough to power up the accessories, but enough to light the test light. So, forget this purple wire for now.

Check the positive battery cable where it hooks to the battery. There should be a couple wires coming off the pos battery cable that have an inline fuse like you described. I think this is where your problem is, (between the battery and the starter) not on the purple wire from the starter to the firewall.

No doubt, a fuse blew somewhere. Have you checked the fuses in the main fuse panel? Even if the ECM was fried, the interior lights should still work.

[dmorlow]

Originally Posted by DelCoch

Check the positive battery cable where it hooks to the battery. There should be a couple wires coming off the pos battery cable that have an inline fuse like you described. I think this is where your problem is, (between the battery and the starter) not on the purple wire from the starter to the firewall. .

We checked fuses here. But the fact is that if you cross the two terminals on the starter solenoid, the car does turn over, which means there's power getting to the starter, so that's not it.

Originally Posted by DelCoch

No doubt, a fuse blew somewhere. Have you checked the fuses in the main fuse panel? Even if the ECM was fried, the interior lights should still work.

We checked all the fuses in the driver's door jam. All are good. Everyone says there's fuses in the engine in a fuse compartment, but we've looked everywhere and cannot find one. Right now, the engine compartment looks like a skeleton, so I don't know where it could be hiding.

[MT-2500]

If you shorted alt you usually will burn out a fuseable link.
On the 96 there is a fuse link between battery and alternator.
Look at battery positive termanal and back of alternator for that fuse link.
Check for 12 volts on the big wire to back of alternator.
If no p12 volts there it is between it and batery positive.
If power there the big terminal on back of alternator feeds power to underhood junction block.
There is 5-6 fuse links there check for lose of power and burnt fuse links at junction block.
MT

[dmorlow]

Originally Posted by MT-2500

If you shorted alt you usually will burn out a fuseable link.
On the 96 there is a fuse link between battery and alternator.
Look at battery positive termanal and back of alternator for that fuse link.
Check for 12 volts on the big wire to back of alternator.
If no p12 volts there it is between it and batery positive.

I checked voltage at the positive terminal on the back of the alternator and there's power there.

Originally Posted by MT-2500

If power there the big terminal on back of alternator feeds power to underhood junction block.
There is 5-6 fuse links there check for lose of power and burnt fuse links at junction block.
MT

I'll have to check that. I didn't see it, but I'll look closer for that.

[MT-2500]

There is one fuse link between alt and junction block.
If no power to junction block look for that fuse link.

If power to junction block there is 5 other fuse links from junction block to all power feeds.

Does head lights or anything else come on or work?

[dmorlow]

Originally Posted by MT-2500

There is one fuse link between alt and junction block.
If no power to junction block look for that fuse link.

If power to junction block there is 5 other fuse links from junction block to all power feeds.

Does head lights or anything else come on or work?

Nothing works at all.

[MT-2500]

Trace 12 volt power feed from alternator to fuse junction block.
It will have a fuse link someplace.
Test both ends of it for 12 volts.
You may have to turn junction block upside down to find it.
IF fuse link is blowed.
A good parts place should have some fuse link wiring.
Solder it in and you will be set to go.
Good luck

[dmorlow]

Well, here's an update. My dad figured it out. When I hooked up the alternator, I hooked it up wrong. There was one red wire and one black wire. I just assumed when hooking it back up that the black wire was ground so I hooked it up to ground. It wasn't. The black wire was positive. I don't know if the manufacturer color coded it wrong or if someone after changed the wiring color. My dad followed the black wire and found all the inline fuses everyone was talking about. He then decided to hook that up to positive and everything started working. So I guess lesson learned is even if it looks obvious how to hook it back up when taking it apart, to label every wire anyways as to where it went when hooking back up.

Thank you everyone!!!

[MT-2500]

Thanks for posting back how it went.
Glad you got it figured out and fixed.
The wiring color code is a bite.
Some wiring use white for ground and black for positive to.

Yes the old school of hard knocks is a good teacher.
Back when I was young that is the way we learned a lot of stuff .
We did not have many schools and books.
But now days we have books and a pc and AF and.
A digital camera also helps.
Snap a shot of it before you take it apart.

Good Luck
MT

[JimmyRiggin']

Question(s), the fuseable link on my 1996 Jimmy would be located on the positive battery cable, right behind the battery, leading to the alternator. Correct?

How many wires should the fuseable link have>> IM only seeing one red one, and a slot that looks like one used to be there. If this fuseable link was bad would it in turn cause me a mess of problems when my jimmy is heated up?

I have unplugged the thing while it was running and nothing seemed to happen? It should be replaced immediatly im assuming?

I can't seem to find any info in my trusty H book on the fuseable link. Any info would be appreciated.

[MT-2500]

Originally Posted by JimmyRiggin'

Question(s), the fuseable link on my 1996 Jimmy would be located on the positive battery cable, right behind the battery, leading to the alternator. Correct?

How many wires should the fuseable link have>> IM only seeing one red one, and a slot that looks like one used to be there. If this fuseable link was bad would it in turn cause me a mess of problems when my jimmy is heated up?

I have unplugged the thing while it was running and nothing seemed to happen? It should be replaced immediatly im assuming?

I can't seem to find any info in my trusty H book on the fuseable link. Any info would be appreciated.

This post is old and started by someone else.
To save from hyjacking.
Best to start your own thread/post.
MT