Electrical Issues

[Nizzan4u2nv]

After replacing my water pump last saturday, I test drive it and all of a sudden the car shuts off, but outside lights/hazards/guages still work, nothing else in the car will. I pull into a parking lot and see that the 30AMP IGN fuse is blown so I take the only other one(rad fan) and put it in, everything turns on, I start the car, then it blows again. So we move the car out of the way and try and see if anything is shorting anywhere, no dice. We have no more fuses so we try and jump the posts where the fuse is, it kinda starts. We finally get it to start perfectly with the screwdriver jumping the fuse posts. So we go home and get another fuse from another car. Drive it home, and its fine. But now, everytime I hit a bump, it shuts off for a split second. It almost shut off completely, and the CEL was flicker for a bit, I downshifted then it was fine. Any ideas? Possibly the bad motor mounts somehow cause the starter to short from loose wires? The car sometimes has a problem starting. You have to turn the key from off to on then off to on inorder for the starter to move. You can kinda hear a little hum sound when it doesnt start, but its been doing that since I bought it. Any suggestions or thoughts? Its really starting to stress me out.

[idlafie]

LOOONG POST!!!...Read at your own risk!!...


FIRST & FOREMOST...NEVER EVER bypass a shorted out fuse!!!
Unless you want to fry your electrical wiring harness and catch your car on fire or blow out your ECU, then go right ahead!!.... Mechanics that come in later to fix all this stuff will hate you for it but then again, they'll charge you for it too!!

Anyhow...sorry bout the rant....I've read & seen one too many S13 & S14 owners do some crazy-ass shit when it comes to electrical wiring & their cars & some of it has made me wonder why their car hasn't caught on fire yet!!

Sounds like you have the classic symptoms of an electrical short in your wiring harness. Any boy are those a ROYAL bitch to find!!

In order to troubleshoot an electrical short you'll most definitely need an a copy of a factory service manual. Use the SEARCH feature here on Zilvia net to find the link to download one for free. Once you locate it you'll have to trace the entire electrical circuit where the 30 amp fuse is blowing. If it's the ignition circuit, you'll also have to check your ignition switch to make sure there are NO shorts in the electronic switch itself.

On S14's the electronic switch is located directly opposite of where you place the key into the ignition. Pull the steering column cover off & remove the two gold colored phillips head screws holding it in place. Once you get the electronic ignition switch off, you can use a voltmeter / continuity tester to make sure the contacts in the switch are good or not.

While you are at it, check all the wires hooked up to the ignition switch and wiring harness underneath your dash. Make sure any aftermarket accessories such as aftermarket car alarm or aftermarket radio are not shorting out your 30 amp ignition fuse due to a faulty connection. Trace the entire eletrical line underneath your dashboard to your engine bay and to the ECU. You're gonna have to use the beeper in the continuity tester to trace each electrical line.

Wiggle the wires to each line you test to make sure there are NO shorts in the electrical line being tested. Also check your connections at your ground points in your electrical wiring harness to make sure all the ground wires are not shorting out at the connection point. Remember, because you have bad motor mounts, everytime you rev your engine your engine will torque an inch or so, (maybe less, maybe more - depends on how bad the mounts are), causing the wiring harness to move also. Over time your harness will short out due to that movement.

Places to check...the spot where the wiring harness comes thru the firewall, the spot where the wiring harness rests directly above the injectors, the spot where the wiring harness curves around the valve cover as it heads to the distributor, the spot directly above the oxygen sensor where the ground wires connect to the engine block, the spot right next to the ECU where all the relays connect to the ECU.

Almost forgot, if you have an aftermarket radiator fan cooling your engine, then make sure it is not hooked up directly to your ignition wires. Hook it up using a electrical relay. The aftermarket radiator fan draws quite a bit of current and can melt your wires over time. That's the reason you want to use a relay hood directly up to your battery for the aftermarket radiator fan. The ignition wire hooked up to the relay will provide power to turn the relay on but the power to the rad fan will come directly from the relay.

Anyhow, sorry bout the long post. Give all the above mentioned a try & see if it helps. Post the results once you get it fixed.

GOOD LUCK!!!

Id

PS:
That humming sound you hear when you turn your ignition switch over is your fuel pump priming your injectors with gas. If you hear a clicking sound instead of the humming sound, then it's a electrical relay. Anyhow, hope this helps.

[ledzeppelin240]

Originally Posted by Nizzan4u2nv

We have no more fuses so we try and jump the posts where the fuse is, it kinda starts. We finally get it to start perfectly with the screwdriver jumping the fuse posts.

Like said above if a fuse blows, it is because the amperage for that circuit has been exceeded. NEVER put a higher amp. fuse in or bypass the fuse. The wiring will overheat and if your lucky it will not burst into flames but just make a terrible mess of melted wires...

"idlafie" had a good post so read it. You most likely have a short to ground (but a short to power will blow the fuse sometimes but will cause some funky electrical happenings).

So there is probably a short between the fuse, to the ignition switch and from there to it's multiple circuits up untill another fuse. Study the wiring diagrams all related to the ignition switch.

[MOUNTAINGARAGE]

any updates? ,my 96 is doing the same thing.....:hammer:

[staygold24]

I had a similar problem with my s14 but the gauges would shut off and also shorted out some fuses. It ended up being a grounding problem and had a humming noise and would not start sometimes. Does your car click when you turn it over and not start or you just hear it then it starts? My hazards and outside lights would all still work just my gauges would not unlike yours.

[Nizzan4u2nv]

Originally Posted by staygold24

I had a similar problem with my s14 but the gauges would shut off and also shorted out some fuses. It ended up being a grounding problem and had a humming noise and would not start sometimes. Does your car click when you turn it over and not start or you just hear it then it starts? My hazards and outside lights would all still work just my gauges would not unlike yours.

The last time I drove it clicked when I tried starting it. When the fuse blew nothing inside worked but the hazards and lights still worked I believe. What did you do with your grounds? Replace or clean?

[staygold24]

Does it click then sound like a humming? I eventually replaced them but cleaned them first and it worked for a while but ended up having to replace.

[Walperstyle]

With the car completely turned off I have a 75a fuse blowing in the relay box in the right hand side (passenger of USDM car)

Being I have two s13's from 1989-1990, i figured i may as well swap the fuse. Well with the car off (but battery termanals connected) i popped the fuse in and 'pop' it blew. I admit it was rather pretty.

...now I have two cars without ability to pop up headlights, and have no interior guage readings (tach, spedo, door open ect). Headlights do turn on, just no motor to turn them up mechanically. thats in the other relay box though.

[Addicted2Kouki]

i have the same problem.
im letting my friend fix it for me.
ill let you know what i find out.

i have a 95 s14.