92 Q45 Electrical Problem...

[jayhotdaynot]

Excuse me this my first post

I got my 92 q 8 months ago.. Named her Suzy Q...i love it, but if its not one thing its the other ( Just like a woman).. i resently had to swap the motor. shes been running good ( other then a little rough idle, but no complaints(( about the engine that is))

Untill it started to idle low.. about 450 (right under the 500 mark) the lights would dim and wen i stepped on the gas they would brighten up and every once in a while it would stall.. i immediatly thought alternator.. soo i took it to AutoZone, and had them do a test( ofcourse She was showing off and wanted to idle normaly and smoothly when they were checking it..) but they said it was normal.. the next time it happened i took off the positive while the car was on and the car stayed on and idled the same at about 450 475... soo i was baffled..

i went on Q45.org and looked it up.. i then cleaned my throtle body, replaced my fuel filter and cleaned my maf sensor,, the problem subsided.. it now idled at about 550 500.. still lower then regular.. but it was still time to time..

the other night the rpms got low.. real low, like before, 450 475.. the lights dimmed, but when i steped on the gas the brightened,,,,, ALOT.. VERY VERY BRIGHT and cut off. soo i drove home( driveing with 2 feet and putting her into neutral to keep the rpms up when i stoped soo it wouldnt shut off) i did the remove the positive thing again.. but this time it went wild! Low, High, Low, High High high, soo high that it blew my headlights and my marker lights... but blew no fuses soo im stuck i wanna get a new alternator, but everyone is saying they dont kno if its the alternator i should check the regulator... Help me NICO

[Q45tech]

The regulator is inside the alternator................never remove a battery or one of its connections while engine is running!

[qsiguy]

The regulator is in the alternator. I'm 99% certain that's your problem. They can go in and out for a while before they completely die. Last time the regulator failed in my alternator my voltage went way up and cooked my battery before I could get home. The electrical system was running at around 18-22 volts. I had my multimeter wired to the cig. lighter when I realized there was an issue.

Your diodes may have failed. If that happens you can get crazy voltages and even alternating current through your electrical system. Wires can fry and bulbs can blow (sound familiar?)

Regardless, there are no other components in your electrical system that can change voltages like that. Not sure about your low RPM other than the possibility of the alternator putting a huge load on the motor and pulling it down when she was throwing a fit.

I wouldn't be surprised if you have multiple electrical devices to replace. Lights, fuses, radio, ECU, TCU, Fuel pump, fuel pump control unit, possibly some wires, the list could be huge. Get a new alternator, preferably OEM, before you try to run it again.

Also, NEVER pull the battery cable while the motor is running. That can fry equipment even with a good alternator. There are better ways to test electronics.

By the way, welcome to NICO. hehe sorry for the circumstances but you came to the right place for help. As you dive in we should be able to help.

[jayhotdaynot]

thanks a mill.. ill get ryte on it..., i think my fuel pump is still good ( i hear it hum wen i cut the key on, i kno thats gonna be another problem as ive been readin), and my radio is still alryte( thank the lord) dont have traction control(even tho i wish i did, Snow is no fun) all my interior lights are good, and my dash is in tact.. Soo im hopein that the headlights and indicator lights are all that went out,,,

i Forgot to add that the display when the car would cut off would say Low Battery Charge... (that shocked the hell outa me cause all it would ever tell me is lies about my Breaks and stop lamp)

And ill be sure to never do that again... and i thought i was mr big mechanic..

Ps. Is there a way to fix my climate control display, with a little bit of banging the display cuts on,, and sometimes it suprises me

[qsiguy]

Some people say that the dash display will say the tail lights are out when they aren't if you use non OEM bulbs. I use non OEM bulbs and haven't had that issue but that's something to look into. It's possible that you only blew your headlight fuses, check those first as well as other fuses. There are some posts about fixing the display on the climate control, try the search feature, I don't have the direct link. It's not too difficult tho, could be just a loose connector or bulb if you can "mallatize it" to make it come back on.

[jayhotdaynot]

Thanks alot guys!!

i got the alternator replaced... i got a rebuilt Nissan alternator, payed $280 for it ( i feel that that is 2 much, but ohh well..) and about 110 for labor.. Soo after taxes everything came up to about 420...

I did it at Sears soo, i have a 6 Month labor warrente, and a 2 year parts.. Not bad.

Thought for a second that i would do it myself.. But then i saw the **** that the mecanic waz going thru, and i said thank god i didnt.

[heywier427]

glad all worked out for you.

have you done the chain guides???

[qsiguy]

So did that cure the issues? Did you have to replace fuses or bulbs? Fill is in so we know the outcome.

[jayhotdaynot]

The Idle has Been regular.. not low or high.. i had to replace the low beam bulb as well as the indicator.. no fuses blew.. i find that odd, but hey... everything works fine...( is this the calm before the storm?)

I havnt done chain gides yet.. but im not sure ir they were already done.. i resently swapped the motor (blew my old one, i had a oil leak because i hit my oil pan, i pached it up but it was still leaking slowly, always kept it filled with oil but i was reading and it said that maybe the punp was damaged and the oil wasnt circulating... Took her up to 145mph one nite, it was fine untill i got off the highway.. then she started knocking crazy) But any way how would i check if my gides were done?

[qsiguy]

Well there's another thread circulating right now where he drilled a hole to look through but that's pretty drastic way to look. It's a pretty big job I guess, never tried it or needed to as I've got the '94 model.

[qsiguy]

Here's the link

zerothread/239309

[Ozzie]

I'm going to go with this theory, as it happened to me that way.....After going high speed, my engine started making god awful noises...Yeah, my timing chain guides bit the dust. But luckily, I replaced them before the chain jumped a cam tooth or two and got my piston crown to kiss the valves.

zerothread?id=162571

I say it quite often, but here it is again....

PLEASE get straight onto the job of replacing your guides. Your engine could mince itself at any time from now.Call Joe at everythinginfiniti (site sponsors). He will get you the parts cheap, and fast.