Electrical short now no power to half the fuse panel

1987we4

New Member
Joined
Oct 6, 2016
Hello all. Been lurking here for the past 1 1/2 years and now it's my turn to join the electrical problem crowd. After 1 1/2 years and nearly 10,000 trouble free (mostly) miles of enjoyment, my current 87 GN has lost power to several fuses in fuse box. I am no expert in this department but do have the basic understanding of how it works. I've been around turbo Buicks for 30 plus years (bought a WE4 new) so I am very aware of all their quirks. Issue started two weeks ago after I noticed the volt gauge erratically bouncing between 12 and 16 volts while driving home. A few minutes later I pulled back into the driveway, shut it off and noticed the fans were still running ( they have never done that before). Turned the key back on for a few seconds and poof, lost power to several things. At this time I also noticed the dreaded faint smell of an electrical short . Popped the hood to look around and noticed that the exposed metal part of the connector to dual fans (intrepid fans I believe but not sure since I bought the car this way) ground out against the intercooler pipe. First thing I checked were the fuses, all looked good. I could find no smoked wires anywhere, under the hood or dash. Next I checked the fusible links by the starter and they looked in perfect shape as well. I then put a test light on the wires and confirmed power before and after each link. I do have power to the seats, wipers, headlights, taillights, radio, ac/heat blower fan, under hood light, interior dome light. I do not have power to the ignition, fuel pump, alky control, aftermarket gauges, blinkers, dash lights. I love driving my car, not sure where to start next and need help. Thanks in advance for any and all assistance!
 
There is link on this site called vortex buick- there you should find the electrical schematic of the GN electrical system. Start by verifying power from each fuseable link at the fuse box. Then check power at the fuse box for each inoperative system that wont power on.

The vortex troubleshooting tree should give you good direction to solving your issue as long as you know how to use a mutilmeter.
 
Thanks for the Vortex buck recommendation. Printing copies of electrical schematics now. Looks like Egyptian hieroglyphics to me but I will drill down and see if I can figure them out. 20 amp gauge fuse has been replaced for good measure with no improvements.
 
Yes. Sorry, forgot to mention the grounds to the back of the passenger cylinder head is clean, dry and the bolt is very tight. Wires look good as well. Replaced ECM & CCCI fuses as well, no luck.
 
Question. Is there a way to temporarily bypass each fusible link, short of cutting/splicing, in order to do a quick test to eliminate fusible links from the equation?
 
Ok it’s been a long time,But it looks like you have power to upper 1/2 of the fuse panel,right?
The plug in the engine compartment is in two separate sections with two power feeds.and the bottom side is usually where we hookup all our add on stuff. You can take your test light and test these for power. If no power Go to drivers side find the big plug,should be a 10 mm headed bolt ,unscrew it and pull the plug and inspect it’s condition.
Be patient electrical problems are never fun.A good test light is your friend,one that will show +and - volt is even better.
 
I spoke to soon there are a dozen power feeds to the back of that plug,but I’m still going to start there.
 
Yes. Sorry, forgot to mention the grounds to the back of the passenger cylinder head is clean, dry and the bolt is very tight. Wires look good as well. Replaced ECM & CCCI fuses as well, no luck.

Did you check the negative battery cable going from battery to block under the turbo?


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With the key on do you have power at the ECM and CCCI fuses? Verify with test light or volt meter. Probe the empty (or used?) battery slot on the fuse panel to see if power is there.


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The negative battery cable was checked and I found no issues. Checked ECM & CCCI fuses with a test light and confirmed they have no power to them in the fuse box. There is no set pattern to missing power at the fuse box. Meaning it's not isolated to just the upper half, lower half, left or right side. I'm pretty certain I probed the battery slot last night and it had no power. I will probe it again for power and report back. I did probe the extra ignition slot #1, located at the upper left, and it had power. Ignition slot # 2 does have power.
 
Sorry, I had a typo in that last post. IGN slot 1, upper left corner, does not have power. IGN 2 does have power. The orange ECM wire by the battery has power. I'll check the pink/black with key on and follow up. Thank you all for your assistance!
 
There are (3) IGN 1 slots and one IGN 3 slot further right of the (3) IGN 1's.

There is no IGN 2 slot.

Replace the ST BLT/ACC fuse which is 20A between the IGN 1 slots left side of the fuse panel.

You then need to test both sides of each fuse clip with the key in the ON/RUN position preferrably with the fuse out.

Report back any that have no power on either side.

Does the fan work on high speed, the fat red wire on the blower fan relay terminal D should have power on it at all times does it? It's mounted right near the blower fan passenger side under the hood near the firewall.

Most likely you cooked fusible link A which powers a lot of stuff and has (3) wires off it down at the starter area.

It shouldn't take more than an hour to test the whole fuse panel and write down the findings in detail which is needed to troubleshoot electrical problems. Pull the plastic panel off that covers it which will make for easier access.
 
Sounds like a blown fusable link down by the starter.

It was a shitty place for engineers to put the fuses. It’s a lot of work to drop the starter and replace the fuses. Then if the fuse blows again, you will be pulling your hair out.
 
Update. Checked and confirmed all speeds work on blower fan. Then checked fuse clips with key ON/RUN as suggested. Hope this helps. No power to GAUGES, ECM-IGN, all three IGN 1 slots, TURN B/U, ST BLT, ECM-SOL, FP/INJ, LPS, CCCI, CRUISE & INST LPS. Now, the CIG CLK, RADIO, PWR ACCY, STOP-HAZ, A/C, RLYS & WDO all have power to the left leg, no power to the right leg. This is with no fuse installed . With fuse installed, power shows up on both sides of fuse when probed with the test light. The PWR BRK, TAIL LP & WIPER have power to the right leg, no power to the left leg. Again, with fuse installed power shows up on both sides of fuse when probed with a test light. All BAT slots have power as well as IGN 3. Also replaced the ST BLT ACC fuse again, no love.
 
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