Resolved 99 GST Ignition issue...No power to nothing...

[roadtrip_69]

So was having transmission/clutch issues a few months ago. And while attempting to start the car, a odd thing happenend. All the dash lights went out, but the DOOR open light. And the RPM gauge would move. But aside from that no power to any ignition component. But due to the transmission issue I back burned that till i rebuilt the transmission.

Fast forward to now, transmission and everything else is in and ready to go. Battery has been out of the car for a couple months with a trickle charger. Hooked it back up, and tested the main power fuse, and alternator fuse and its getting battery voltage. The ignition fuse is also getting power. I went ahead and replaced the ignition switch just to eliminate it as a cause.

But still no power to the radio, the hvac fans, no fuel pump sounds, no dash lights. Checked every main fuse and the dashboard lights fuse in the car. But still no power.

Figured maybe there's a ignition relay some where but all I can find info about is the MFI and Starter Relay. But the issue is prior to both of those relays. Its whatever distributes power when you turn the key.. aka what I believe is just the ignition.

Any body know what I'm missing. Starter is brand new, battery is charged. Main fuses are good. New Ignition switch. I'm at a loss.

 

[roadtrip_69]

Update - Also I get the buzzing sound when you put the key in the ignition.

I have checked continuity of the new and old ignition switch. Both are good. I am getting power to the switch but then it seems to go no where. No HVAC fans, no cigar lighter, no dash lights but the open door one.

Is the starter relay involved in this. I mean not getting any cranking either, but considering there's no ACC to begin with I feel the problem starts before it gets to the "ON" or "Start" position. I have even jumped power from the primary ignition wire "position 1" on the switch to the terminals 2-6 and nothing powers on still. So definitely NOT a switch issue.

Door locks work, dome lights work, head lights work. But nothing that runs THROUGH or because of the ignition being turned on.

Losing my mind here.

 

[steve]

I don't have a 99 FSM set, these are from 98 and should be really close.

Start measuring from the battery and check each leg/branch to see when you stop seeing the voltage. You can also read the diagram and note which circuits have power and which don't and then look for the last common point between them.

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[roadtrip_69]

Thanks I have the full service manual. My issue is electrical diagrams are my kyptonite. Lol I can tear apart and put back together an engine or transmission in an afternoon. But electrical crap.. confuses me. All signs in logic point to a relay or a bad ground... but there's no "ignition" relay. Which is really throwing me off. Plan on spending some time in the coming days on just eliminating what I can as options.

Thanks for the diagrams.

 

[luv2rallye]

Do you have +12v at these engine fusebox terminals?

2G - 99 GST Fuse Box help

ok, I need a pic or someone tell me if I'm missing something...have a 99gst that im rebuilding for the wife, and notice that one of the fusible links AKA big A$$ fuse was busted/blown and the other missing. So i got them and noticed that on the 60amp that there is only 1 wire to the box facing...

www.dsmtuners.com

 

[roadtrip_69]

Thanks, that much I have confirmed. Though I also have custom wiring for the alternator itself with a huge 0 awg 2|0 awg. I forget which, with its own inline 120 AMP fuse to go with my upgraded alternator thats supposedly 150 amp I believe.

I have power though on the 100 amp and 60 amp fuses. There is also power getting to the ignition fuse. Swapped out fuses as well to confirm its not a blown fuse that looks good.

And can confirm that at the switch itself, ignition switch I have power to the 10 gauge w/b wire. And I have tried to bypass the switch, (even after completely replacing with a new one) and jumping power to the ACC terminal to see if I got anything to come on. But still nothing.

I was reading/studying the power distribution diagram and I wonder if fuseable link is a fuse outside of the fuse box? some where along the path AFTER it leaves from the ignition?

I'm going to attempt to find the mfi, and starter relays today, and see if they are getting power. I actually bought a replacement duo.. as they are part of the same mount together years ago for another issue, that turned out not to be related to the relays. Ill swap that out and maybe the relay is just stuck open or in a bad start not allowing the circuit to fully form?

I'm great with a multimeter, and determining voltage and ground.. But reading the path of things in those electrical diagrams with the spilt offs and what not become a nightmare .

 

[roadtrip_69]

So mystery solved. After literally tearing apart everything sans the main dash itself and testing every fuse and relay and inspecting every wire in sight. I determined that one of the main power cables..well multiple cables combined into one, going into a distribution block. Was corroded to the point that it tested voltage when I checked it initially but also had a short due to the corrosion so the process of testing disturbed the connection. I concluded that even NON ignition related components were not working, such as headlights and the horn. So i worked backwards and started back over thinking it had to be a major ground .. had the key on, and when i wiggled the power cable near the fuse box I could hear relays clicking. So removed the wires, stripped them, cleaned them, and then reconnected. Wala, power to everything. Sigh..

Occam's Razor