polito Racing

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i have a 87 T II for some reason it wont turn off i replaced the ignition switch, checked the alternator cables and there is no contact beetween them,Im thinking there is a relay stuck somewhere but i cant find a relay box. does anyone else have any sugestions?

J-Rat

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Only time I was involved in this, it turned out to be a faulty alternator.

lax-rotor

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Is it staying on? I've heard of wires being reversed on the alternator causing it to run longer than normal.

shadow7

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let it run out of gas... ....jk.. do you have a turbo timer????

my friend had a problem similar to this. it was something to do with the ignition wires under the dash and the turbo timer,,,im nut sure but check

polito Racing

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I dont have a turbo timer. I've kept on messing with it i did find that one of the little cables of the back of the alternator made continuity when puttig the fest lead to ground. are they both positives? or a positive and a negative?

thanks for your support!!

mike_merryguy

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polito Racing

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J-RAT how did you determne the problem was the alternator?

Icemark

did you replace the alt? If so it is probably wired wrong.

Red_Rabbit86

what about your ignition it self where you put your key in???

HAILERS

Written for Mr J-Rat....................start the engine. Idle the engine. Turn the key to OFF. IF the engine is still running, then go to the alternator and pull the small two wire plug off the back of it. Did the engine die? IF so, the alternator is kaput OR the two wires on the plug are crossed up.

Pulled the plug off and the key is in OFF? and the engine is still running? Then it's *another thing*.

Then you need to remember just what wiring you have been messing with lately. Like the radio wiring.

I'd estimate it takes about five to ten minutes to do the *test* I wrote above. Not a big deal.

Why would the two wires being swapped on the small plug effect things? IF a series four, then you'd have the alternator putting approx 13-14vdc on the BLACK/WHITE wire instead of the WHITE/BLACK wire. The Black/White goes to a fuse that feeds the ignition circuit, if memory serves. That's why.

EDIT: well if it's a turbo, it's a little more difficult to access the alt plug.

There is no RELAY in the system except the Alt relay in the CPU. That relay recieves a GND signal from the alt when the alt is not turning over. That gnd pulls the alt relay in and puts another gnd on the Warning LIght cluster to turn ALL of the warning lights on. That relay is NOT a player in your situation.

Next time this happens, while the key is OFF and engine running, pull the ENGINE fuse in the interior and see if the engine stops....or not.

I'd still do what I wrote above. I do believe that alt small plug CAN be disconnected with the engine runing. Just a little more difficult, but possible.

Don't leave the small plug off the alt while the engine is running, for any length of time. Just pull it off. Engine should die. Not dead? Put plug back on or kill the engine by dumping the clutch with transmission in gear. Then put plug back on.

Another question. Say the engine keeps running and the key is OFF. So now dump the clutch with it in gear to kill the engine. Question: Do you have any lights on in the cabin NOW?

polito Racing

iTrader: (1)

Im going to try the pulling the cables out thing and ill let you know. when i take the key out everything keeps on working normal no warning lights come on exept for the E brake light and the seatbelt and when i turn it off with the clutch all the lights turn off as normal. after the engine stops no lights come on. what i mentioned earlier with the alternator one of the little cables makes continuity with ground but not beetween each other. is this the way it is supposed to be or could this have something to do with the problem. something else is that sometimes it does turn off with the key wich kinda threw me off.

HAILERS

If the key is ON, then you will see voltage on both black/white and white/black. I'm talking about the plug being off the alternator when you do this.

You see voltage on the white/black because your backreading thru the coil of the alt relay in the CPU. Pulling the CPU's plug will make THIS voltage go away.

You see voltage on the Black/White because it's connected to the ENGINE fuse in the interior. Pulling the ENGINE fuse in the interior should cause THIS voltage to go away.

Forget about ohming the two wires out. Just look for the voltage described above but FIRST do what I suggested in my other post and disconnect the small at plug AFTER the key has been put to OFF (and the engine is still running with key to OFF).

Interior fuse box should be shown here: https://www.rx7club.com/forum/showthread.php?t=494667

The ENGINE fuse powers the black/white and the alt relay is powered by the Meter fuse. This relay is NOT your problem imho.

HAILERS

What happens when you turn the key to ON, is you activate the fuses and their circuits on the fuse box in the interior. You activate the part of the fuse box called IG 1. See page 50-12 of the online 88 FSM wiring diagrams.

When you turn the key to OFF, you deenergize this *bus*. What is happening to your car, is that *something else* is energizing that IG 1 bus with the key to OFF. The most logical thing that can cause this is the alternator or it's wiring feeding that bus when it should not be doing so. A bad diode in the alt MIGHT cause this problem.

I KNOW (as in KNOW FOR SURE) that if the two small wires on the alt are swapped around, that you will have YOUR problem. Been there and done did **** up that arragement all by myself ONCE upon a time. Fixed same.

This is not to say something else is backfeeding the IG 1 bus. Like some fooling around with radio wiring etc, new boost controller/whatever and getting wires going where no wire should go blah, blah, blah.

BW wire goes in the top hole near the keyway for the plug.

HAILERS

White/Black takes a gnd FROM the alternator and puts it on the negative terminal of the alt relays coil in the CPU.

Once the key is put to ON, that wire should read approx 3vdc The gnd from the alt is removed, IF MEMORY SERVES. The 3vdc is excitation voltage for the field in the alternator if memory serves. The 3vdc comes from the regulator in the altenator. Engine started it will read 12-14vdc.

Black/white comes from the engine fuse and is the voltage going to the voltage regulator in the alternator.

Checking for gnd on these two wires might very easily result in a reading of an ohm or less with the key to Off. Not worth doing.

Like I said, key to ON, engine OFF, plug off the alt, both will read approx 12vdc for the reasons suggested in a post I made above. PUll the meter fuse and volgage should disappear from the whtie/black and pull the ENGINE fuse and it should disappear from the black/white.

J-Rat

iTrader: (2)

Actually, my friend here Digi7ech discovered this little phenomena... Very interesting!

HAILERS

I agree, if NONE of the wiring has been disturbed, then the alt is a very likely suspect.

If any other wiring has been disturbed just prior to this *PROBLEM*, then you might suspect another thing than the alternator itself.

Like I said, thru gross incomptence I once had those two wires on the alt crossed up. Oppps. Fixed in a hurry though.

P.S...........They have a CAGE ready and waiting for you at the military prison at Fort Leavenworth. humor for the Rat.

polito Racing

iTrader: (1)

ok guys this is what happened. i checked the cables and they were both in the right place. when i took out the engine fuse the A/C cooling fan went off and as soon as i put the fuse back on it stopped. one of the cables had 12 V as expected the white one had .223 V. Now the lights in the doors dont work either. i checked the fuses and none of them work, the lighter works, the radio cables have power, the two flood lights work the room light only works on the on position same thing when the door opens it wont turn on and neither will the door open warning light. no other cables were removed only the two little cables behind the alternator. I also noticed the fuel pump just keeps on running when the ignition switch is set to on it doesnt stop at all i taught it was supposed to after a little. I'm starting to think there is a very bad short somewhere in my car. anyone else have any sugestions. should I go ahead and take it to the shop or should i keep on trying?

polito Racing

iTrader: (1)

also forgot to mention the horn doesnt work either!!!