So I have an '88 GTUs that hasn't been started in a while from the previous owner. I got some stuff hooked up and now have a wiring gremlin I can't get rid of. Basically, the IGN is always hot.

What I have determined is that the driver's fuse panel always has Battery going through the ROOM fuse, and IGN going through the METER fuse it seems. These fuses actually blew the first time I went to crank it. I have since put higher amp fuses in while testing and they don't blow.

My question is this, has anybody ever had this problem? It is causing my IGN to stay hot so the main relay is always active. Hook up the battery and the car comes to life, stays running with the key out of it, etc. I went through the wiring diagram and tried all kinds of stuff last night. I got it re-wired where I disconnected the black/white wire from the main relay, and ran that directly to the IGN from the ignition switch. Not at least my main relay only comes on with the key.

The problem is my voltmeter on the dash constantly shows 12V until I disconnect the battery. If I pull the METER fuse, it still shows 12V. Pull the ROOM fuse, and it drops to 0. It seems to me like that METER fuse is getting 12V passing through it somehow.

I know this might not be the best description, and I will try to clarify for any questions asked.

SUMMARY:

IGN is always hot. Seems related to the driver's side fuse panel getting 12 when it shouldn't...

THanks,
Scott

 

I should mention the car currently has no dash installed except for the guages plugged in. Can anti-theft cause any of this craziness?

 

off the top i think the ignition swtich turns on the main relay, so yes an alarm could cause that (although it would have to be on the wrong wire?, alarms usually only cut the starter wire, and everyone knows this, which is why alarms don't work)

 

The Engine fuse is what provides power to the Main Relay w/key to on. It is a B/W wire at the two wire plug in the relay in which the Engine fuse powers up. If this wire has constant voltage then you might have the alternator wiring switched. The B/W wire is on top of the W/B wire and not reversed. Just unplug the two wire connector to the alternator and see if your problem disappears.

 

And the Room fuse is part of the battery buss fuses so it should always have constant voltage. And you should be using the correct amperage fuses and not using higher rated fuses.

There is a Black/Red wire in its own plug that connects to the Ignition Harness. This wire only should have voltage w/key to start. If you unplug this single wire from the Ignition harness the wire should not have voltage w/the battery connected. If it does not then the Ignition Switch is likely faulty.On a side note, does your car have Cruise Control?

 

That B/W wire is always hot with the battery connected and the key off. I don't currently have an alternator wired up, but perhaps the wires by the alternator are crossed somewhere somehow.

I would like to run the correct 7.5amp fuses, but for troubleshooting I put bigger fuses in to test things out. If not, they just keep blowing.

 

Unplug the two wire plug connecting the Ignition Switch to the plug w/the B/W wire and the solid Black wire. Then measure the B/W wire powered by the Engine fuse to see if it still has constant voltage. If it doesn't then you know the Ignition Switch is at fault. If it still has voltage then you know the Engine fuse is being backfed by a buss fuse.

An improperly wired starter will also cause the starter to turn over but the car needs the Main Relay to close for the car to start though.

 

The B/W wire at the ignition switch is being fed power. It is constantly getting 12V. The only way I can make it work is to unplug the B B/W connector from the IGN switch, and jump power to the White/Red wire, then run a dedicated wire from the IGN B/Y to the B/W at the main relay. This allows the main relay to work as intended. When doing that, the fuse panel in driver's side is always HOT still and the voltmeter on the guage is reading 12V.

So I agree somewhere the Engine fuse is being backfed. How do I figure out where it is coming from?

As for the starter, I bypassed the starter cut relay and just ran a wire from the START wire (B/R) on the IGN switch and ran it to the starter signal wire. This allows the Starter to only work in CRANK.

 

If the Engine fuse is always hot then there would be no reason to jumper a wire from one of the IGN fuses to power the Main Relay or does this Engine fuse lose power w/the two wire plug disconnected from the Ignition Switch. Follow?

 

I might have been unclear. If I plug in the Ignition switch wires as intended, and turn on the battery (have a battery cutoff switch), the main relay instantly goes hot because the B/W wire at the main relay goes hot.

What I did was disconnect the IGN wire at the Ignition switch, and ran a wire from that to the main relay B/W. This allows the main relay to only come on when the key is in IGN or CRANK. Since the Battery wire is on the same 2 wire connector in the ignition switch, I had to jumper power from the chassis side of this connector to the W/R battery wire on the ignition switch.

Does that make sense?

With all these combinations, the guages constantly show 12V until I pull the top 7.5amp fuse in the driver's fuse panel, or shut the battery off.

 

What's a bit confusing is the W/R wire you speak of at the Ignition Switch. The starter wire from the switch should be Black/Red. And this wire should be located in its own plug.

 

The W/R is the battery wire into the switch. I had to jumper 12V to that since I undid the connector that both that W/R Batt wire, and the B/Y IGN wire are on.

I know the starter wire is B/R

 

Still not clear on this W/R battery wire. Are you talking about a wire which is powered by the battery at the Engine fusebox which is W/R? This would be the BTN? And you can unplug a fuse at the interior fusebox and see if the Engine fuse is no longer powered up or did you make mention of this already? You can pull the BTN fuse and if this cuts power to the Engine fuse then you can narrow down the backfeeding to the Buss fuses located within the interior fusebox.

There is also a forth plug at the Ignition Switch that has but two wires. One is to power the lttle bulb for key illumination and the other is a signal wire to the CPU to tell the driver that the key was left in the ignition. Perhaps one of these is W/R and this is the wire you mentioned. If you're using one of these wires then you shouldn't as they are very dainty and not powered by a high enough amperaged fuse.

Also, the Engine fuse powers the B/W wire at the Main Relay, alternator, Circuit Opening Relay and an automatic transmission component. You might want to unplug the Main Relay and see if the B/W wire at this relay still has constant voltage or not. If this does not work then you could try doing the same thing w/the other relay.

 

The White/Red battery wire is the Battery wire on the ignition switch. It is a big gage wire and is on the same connector as the Black/Yellow Ignition wire for the ignition switch. Those are the wires that I have messed with, plus the afore mentioned starter wire (Black/Red).



The White/Red wire can be seen in this photo.

 

Your pic is not working but there are only four plugs connected to the Ignition Switch and none have a B/Y or W/R as they are B, B/W, Blue, Two B/R wires plus the wires from the forth plug and that is all. Now the Main Relay has two wires supplying constant voltage to the Main Relay as one is B/G and the other is White /Blue. W/the relay closed the voltage from these two wires powers a B/Y and B/W wires. I think you're being a bit liberal by using the term Ignition Switch or you have completely different colored wires then the wiring diagrams indicate.

 

Did you try to click on the box where the image should be?

 

Yes, the loading image just goes round and round.

I think I understand what's going on now. The Front harness connects to the pigtail of the Ignition Switch and I am talking about the wires which are part of the Front harness such as solid Black and a B/W wire in one plug thus I am not talking about the pigtail colors and I'm guessing you are.

Pic of Ignition Switch pigtail: http://www.mazdatrix.com/86-92Electrical-Chassis.htm

 

Yes, I am referring to the colors on the switch side of the harness, not the chassis side.

 

Well that explains that and on a side note the FSM does not even delinate these wire colors at all. So, with that being said you need to check to see if you have the two plugs w/two wires each switched by accident although I'm not sure if this is possible.

 

No, they at least made those one male and one female for the chassis side/switch side so you can't do that.

 

Then you need to go back to the Engine fusebox and pull the BTN fuse and then check the B/W wire powered by the Engine fuse to see if it has lost its constant hot voltage.

 

BTN is the 2nd fuse from the driver's side with the white/red wire coming from it? I ask because my fuse cover doesn't exist anymore.

I think we did that last night and it killed power, but I'll confirm when I get home from work today.

 

Yes, it is W/R. And if it does then focus on the following buss fuses. ABS, Illumination, Stop, Room, Antenna, Hazard, Heater and Defroster fuses found in the interior fusebox.

 

I will have to go pull all those and see what happens to the B/W wire, but I know if I pull the ROOM fuse, it loses its 12V.

 

I am out of town this weekend rally-x racing my other car so this will have to wait until Sunday night unfortunately.