Electrical Problem

[seyath]

I have an electrical problem with my S13.A few weeks ago, the radio would randomly shut off whenever I stepped on the brakes. The alternator turned out to be bad so I replaced it. The problem stopped. I then also replaced the negative top battery cable, the one from the battery to the engine block. I also got my battery recharged for the problem started happening again. Now nothing works when the car is not running. I can switch it on but the windows won't go down, the seatbelts don't move, the radio and even the clock won't come on. When I start the engine everything works fine. However only when I am pressing the accelerator or cruising. Whenever I let go of the accelerator and press the clutch, or just depress the brakes, the radio shuts off and all the lights become dim. I need help! Still trying to figure this out!

[Dattebayo]

Sounds like a TCU problem...

Search for "time control unit" or "TCU". There is alot of crap on this in the archives.

Edit: As for the radio stopping running on turns, I had to re-do the power antenna line that is blue with a whit stripe to all the other blue w/ white srtipe wires.

[seyath]

***Update***The radio only stops running when the brake is depressed. Even if the car is in neutral parked. Also, all the electronice don't come on in the car until I press the accelerator at which point everything works and for some weird reason the wipers come on for two cycles, even though they are off... I'm perplexed

[Dattebayo]

hello?

TCU? Fusable link?

Do you need to know where to find them? Pages EL-87 & 88 in the FSM. Accessory relay (blue) or TCU near the fuse block inside the car under the steering wheel all the way on the left.

Edit: It also could be the accessory relay above the inside fuse block... its kind of a ***** to get to cause its up under the dash. Its also blue.

[ricebike]

i dont think these items would cause the problem; it doesn't hurt to check, though.

may have a short to power... mebbe some insulation has rubbed off & you're touching wires.

dayum, i hate it when it does that. post to nissan online mechanic section if the fuse/tcu is not the cause...good luck!

[seyath]

I'm about to go out and pull out the TCU. If that is the problem, is the unit repairable or will it have to be replaced? If it has to be replaced... how much?

[Dattebayo]

Try the accessory relays first.They are easier to test.

[seyath]

G'Damit!!! It's so freakin tight down there!!! I need the car cause I work every night, so I guess I won't be dismantling anything until saturday afternoon. As long as the car moves, I can bear with the crappy electronics for a few more days. If anyone has any pics of the removal or a DIY guide/walkthrough I'd greatly appreciate it. I'm getting pretty damn good with mechanical problems, but I'm still struggling with electrical work. Thanks for your help!

[Dattebayo]

I'll send you some pages from the FSM that you might need and some notes to your email.

[seyath]

She's alive!!!!!! Thank you all for your help. Turns out that in the engine bay fuse box, I never had a 30a fuse for the ignition. I had a screw making the contact. Needless to say the most elementary thing was the last thing I thought of checking...BTW, now that I replaced it, the car redlines at 5.8k-6k instead of the usual 5.5k.... Weird...

[Dattebayo]

BTW, now that I replaced it, the car redlines at 5.8k-6k instead of the usual 5.5k....

What are you talking about? What do you mean by redline?