AZmocoLoco said:

I was going about 65mph on a highway in the night time and all of a sudden all of my electrical stopped working. I lost fuel pump power, fan power, headlights & tail lights, basically all electrical, except my interior lights when I open the door.

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Wow, that must have been exciting!

However this should be pretty easy to find. Pop the cover off the fuse/relay block at the right of the engine compartment. There are both regular push-in fuses and 'fusible links' which are higher current, like 60, 80, 100 amps that have screw connections. With a voltmeter check power at both ends of each of those links -- there should be +12V at both ends of each. If I had the electrical manual handy I could prob'ly tell you which one, but just check what you see and I'm pretty sure you'll find it.

Hope for a loose connection because if it's a blown link you have to figure out why. First thing I'd check is are they all the right size -- the cover shows sizes. If someone replaced a 100 with a 60 then you'd get exactly what you got -- driving at speed with a lot of accessories on (heater blower I'll bet, plus the headlights, maybe a powerful sound system ...) you blow the too-small link.

Good luck with it!

I’d start with the alt fuse as mentioned. Do you have a log from the drive? Did you check battery voltage afterwards? I would rule out the ecu for now since your accessories aren’t controlled by it.

I spent about a half-hour this evening staring at the Electrical Manual -- I too have a GS-T and I'm new to the breed so that's useful even without a specific problem to think about.

I'm not very happy with what I learned. The things you list as being dead -- headlights, fuel pump, and fan -- aren't all on any one fuse, particularly when you say the courtesy lights still worked. The circuit that covers the biggest chunk of that would be the theft alarm and the circuit that disables the car if it is broken into. However that's probably a place to look only after all the easy stuff is checked.

The battery and alternator aren't the trouble: Either of those that fails but doesn't cause smoke will give you a problem that gets worse gradually -- at least over an hour or so.

I would first be sure that the problems are still there. Then check all the fuses in the engine compartment 'relay block.' If any oddities are found you have a place to start and since it all happened at the same time, any thread you yank is likely to unravel the whole sweater.

The ECU is a possibility. If all the fuses (but one or two small ones -- I think a couple are turned off unless the ignition is on) have power on both ends then turn on the ignition and watch for the CE light to come on and then go off in five seconds.

Most of my experience has been on Expo LRVs -- simpler cars in just about every way. For that I'm a lot gladder now than was a few months back when the GS-T joined the driveway.

A bad ignition switch possibly also.

oh man where do i start...
the previous owner of course...
long story short: locking, then unlocking the doors would cause the alarm to go off. it turned out to be the driver side door acutator, that i found with broken wires. im not sure if they were cut, or broken. like i said, previous owner.
I completely disconected that actuator (inside the door panel itself all the way to the back). im starting to wonder if they shorted it out and something happened there... ah man the plot thickens.

so i dont even get door chime or start chime. i have no power to my gauges, none to my dash cluster. a bad ignition switch can possibly be the culprit. but now that i think about it, i did the door thing before it happened. the car drove about 50 miles before it shut down.

thanks for the reply guys! ill update as soon as i can.

Thanks guys, I replaced the fuses and still have the same issue.

Nobody has mentioned the MPI relay. Couldn't that be causing this?

We're on Boost said:

Nobody has mentioned the MPI relay. Couldn't that be causing this?

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I was thinking that also! Ain’t that the one on the firewall?

AZmocoLoco said:

long story short: locking, then unlocking the doors would cause the alarm to go off. it turned out to be the driver side door acutator, that i found with broken wires. im not sure if they were cut, or broken. like i said, previous owner.
I completely disconected that actuator (inside the door panel itself all the way to the back). im starting to wonder if they shorted it out and something happened there... ah man the plot thickens.

so i dont even get door chime or start chime. i have no power to my gauges, none to my dash cluster. a bad ignition switch can possibly be the culprit. but now that i think about it, i did the door thing before it happened. the car drove about 50 miles before it shut down.

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The car is really dead, right? The fusible links are okay but when you turn the key in the ignition, not a sound. Is this a second thread that possibly involves the anti-theft circuit disabling starting?

First, I would not disable, cut, or unplug anything inside any door without a through study of that circuit which I'd guess is going to take you some time. Once the start of the engine is disabled because the theft alarm system thinks the car is being broken into, I think turning a key in one of the locks is the only way you can turn off the disable function. If the wrong wire is cut then even that might not work.

What I would do first is try turning your key in the other passenger door lock and the trunk lock. Try both ways in each lock -- this should disarm the system including cancelling the theft disabiling system. However I can't guarantee that the stuff that's cut in the driver's door won't kill disable everywhere -- it's a complicated circuit.

If turning a key in the other locks doesn't work then I would get a 2g shop manual (there's a downloadable version available through this site), in Vol. 2 (Electrical) locate the 'Starting System' diagram for your car (with/without turbo, MT/AT) and trace the power to Starter Relay.

Basically the starter solenoid is controlled by a relay -- the Starter Relay. In cars with theft alarm, the starter relay power goes through a theft alarm relay that's controlled by the Electronic Theft Alarm Control System (ETACS) ECU. So if that ECU doesn't turn on the Theft Alarm Starter Relay to turn on the Starter Relay it's not going to crank or do anything else.

One input to the ETACS ECU is from the switches in the doors, quite possibly via some cut wire.

The two Starter relays are a pretty simple circuit and I think both relays will be in the block in the engine compartment. You'll need a voltmeter and the right diagram; Starter Relay is B-57, Theft Alarm Starter Relay is either B-43 or B-44, depending on which car you have. The relay numbers are on the cover of the block I think.

Possible problems are either relay is bad, no 'ON' signal from the ETACS ECU, or the starter solenoid. When you know the answer to that, the next step will be obvious, though perhaps not simple.

In the end you probably have to fix all the stuff in the door unless you want to just bypass the theft alarm disable function. But -- one step at a time.

AZmocoLoco said:

I was thinking that also! Ain’t that the one on the firewall?

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I think it would be in the cabin somewhere but on the 2g I don't know where!
Here is the full writeup on the 2g MPI relay though:

https://www.dsmtuners.com/threads/2g-basic-ecu-mpi-circuit-function.497188/

As for the alarm system the PO put on your car, I don't know, maybe it could be disabling your car if it has lost its mind or something. I had one of those PO alarm systems on my car. When it started giving me trouble, I tried the easiest most reversible way of disabling the system. I unplugged the inline fuse in the wiring that goes to it. There might have actually been 2 fuses to it, I don't remember. Anyway it disabled the alarm system and didn't hurt anything else. Eventually I unplugged all the small connectors from the alarm unit and took it out of the car and still it didn't hurt anything. So if you wanted to check to see if the alarm is at fault, you might be able to try that.

Another possible PO problem - does your car have one of those little keypad things that disables the car when it's parked, and then you punch a code into it to enable the ignition? If it does, maybe that has lost its mind.

I swapped MPI relays and got no change. I plugged in a black box ecu to see if that would make any difference, but still no door chime, no power to head lights, basically the same situation.

AZmocoLoco said:

I swapped MPI relays and got no change. I plugged in a black box ecu to see if that would make any difference, but still no door chime, no power to head lights, basically the same situation.

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It will not be mpi relay or ecu as those don't control what you mentioned. This was mentioned earlier.

AZmocoLoco said:

Thanks guys, I replaced the fuses and still have the same issue.

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Which fuses?

pauleyman said:

Which fuses?

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i replaced the 60 and 100amp fuse. i had an external relay that i was positive was the problem. changed it also, no fix. im ready to change the ground cable to the battery!

i replaced my driver side door regulator at the beginning of all of this. i sprayed everything with silicone spray. im starting to wonder if something got shorted out! i dont even know. what i do know is that i have a spare 2gb with all door mechanisms and wiring intact in the door. i will probably cut & splice the old wiring that PO hacked if i cant find any smoking guns via reading the wires. i have a feeling the dash will be pulled out during this process.

the summer is almost here in AZ, so i wouldnt be driving the car normally anyways. ill start reading wires this weekend. ill go over all the fuses and relays again too. probably friday night.

thanks guys! we will get this!

One thing you could do is pull the theft alarm starter relay (B-43 or B-44) and check for voltage on the coil when you try to start. If it's an ETACS problem there'll be none. Then jumper the contacts and see if that starts it or allows starting -- without going back to study the circuit again I can't say which might happen.

Replacing all the wiring in the door with original seems like a very good approach if you have to get in there.

I replaced both door harnesses, and door actuators. Still no power. I have door lights and the door open light will turn on in my cluster. Still no power to anything else.

I replaced the two relays stuffed under the dash. I believe the alarm and the door lock unlock relay?

The weirdest thing is happening now. My passenger side won’t lock or unlock with the buttons, and when I hit lock twice on my driver side door, the security light becomes enabled. The passenger side will lock the driver side, the drive side will only unlock… I can’t figure it out!

Probably you should tell us what is the make and model of the alarm system that the PO put in the car. Maybe somebody familiar with the brand will have some ideas about it. Or the manual for it might have some clues. I hated mine. But I think the worst part of mine was installer caused, more than the system itself. Never did totally figure it out. Mine was a Viper 550 ESP.

We're on Boost said:

Probably you should tell us what is the make and model of the alarm system that the PO put in the car. Maybe somebody familiar with the brand will have some ideas about it. Or the manual for it might have some clues. I hated mine. But I think the worst part of mine was installer caused, more than the system itself. Never did totally figure it out. Mine was a Viper 550 ESP.

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I don’t know what they system is. It’s not in there. It’s just a mess of wires

AZmocoLoco said:

I don’t know what they system is. It’s not in there. It’s just a mess of wires

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If there's a bunch of wires with small connectors on the end that are not connected to anything - just kind of hanging around under the dashboard somewhere, then maybe the PO took the actual control unit out of the car before selling the car. But chances are there might still be a couple relays or a "bump" sensor hanging around in there somewhere too. The "bump" sensor would set the alarm off and maybe even disable large amounts of the car when it feels the car get bumped while it is locked, or armed.
There's another thing you mentioned early in the thread, about the door wiring. In the system I had, there was a procedure for getting the system acquainted with a new remote, which you would have to do every time you bought a new remote. Part of that procedure was that you had to do it with a door open. Yup. As I remember, the system was supposed to be wired up with the interior lights circuit, which is turned on and off by the car's door switches. Also there was a "Valet" switch which was a simple little button. The procedure for "learning" a new remote was:
1.) Open a door.
2.) Turn ignition key to "On".
3.) Then you press the valet switch some number of times. The number of times selects what it is that you want to do with it, for exampe, learn a new remote, or, disarm the system, or, arm the system.

Anyway all this stuff kind of rings a bell to me, if it is remnants of the previously installed alarm system that is causing your problem. Maybe it's not, maybe it's some perfectly sensible thing with the car itself.

If I can post a pdf here I'll post a copy of the whole user manual for the Viper 550 ESP that was in my car. It might give you some ideas about what is going on with your car.

Here's just a snippet from it, about a relay in the system that apparently can connect or disconnect power to various parts of the car. I thought this was interesting enough that I took this screen shot way back in 2013:



Viper 550 ESP manual:

Found a power cable burned out. I spliced it (years ago) and it must have touched somewhere at the exposed part. I’m going to repair it tomorrow and see what happens. This is the problem I am sure of it!

Good! Is that the wire that goes from the alternator output to the fuse box?

We're on Boost said:

Good! Is that the wire that goes from the alternator output to the fuse box?

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From the battery to the 100am fuse in the fuse box. I have my fuse box relocated, that’s why it’s extended. I pulled the oem off of my junk car, figured out the eyelets and proper gauge and wire type. My 15 year old son (who is studying for his learners permit) built the new wires for us. I will be installing them this evening. No rush. It’s still hot in AZ so I’m hoping to have it all back together by September. Another weird blessing in disguise…

Glad it was something sensible that you can actually see once you find it, and not some weird thing!
That wire from the alternator to the 100 amp fuse, as far as I know, is not protected by any fuse in the car for current going from the alternator into the rest of the system. So when it shorts to a ground, you got an arc welder there. For about a few milliseconds. Right? I'm not really sure how that works and what happens to the alternator when that happens. Seems like it could be really bad for the alternator, or maybe the alternator has a way of protecting itself and it's just the wire that goes poof?

We're on Boost said:

Glad it was something sensible that you can actually see once you find it, and not some weird thing!
That wire from the alternator to the 100 amp fuse, as far as I know, is not protected by any fuse in the car for current going from the alternator into the rest of the system. So when it shorts to a ground, you got an arc welder there. For about a few milliseconds. Right? I'm not really sure how that works and what happens to the alternator when that happens. Seems like it could be really bad for the alternator, or maybe the alternator has a way of protecting itself and it's just the wire that goes poof?

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I couldn’t tell you. The wire between fuse box and alternator were fine. It was from the battery to the fuse box that was toast. All back together and running fine now. This was a long 6 months, but I did save a ton of miles by it being down for that long.

Thanks for the help everyone.