Help. Shorted my FD, now no start
 

Yeah, I'm embarrassed. I was working on a relatively simple project and accidentally shorted the alternator to a ground on the intake manifold. See picture. I was a bit surprised that the cable on the alternator was hot. Anyway, now the car will crank, but not start. I'm not getting any fuel smell so my ignorant guess is that I fried the fuel pump or a fuse?

I've been going over the wiring diagram but so far have not found it. Does the fuel pump have a fuse, and if so where is it? What else might I have shorted out and any suggestions on where to look?

I've only had my FD 3 weeks and I've already broken it. :(

I shorted it out between the two arrow points.
http://i95.photobucket.com/albums/l1...7/PICT0002.jpg

The fuel pump has a relay located in the front most fuse box in the engine bay. It's right next to the hood latch.

https://www.rx7club.com/attachment.p...1&d=1200373090

Get a tester and find the fuse you blew.

Open the diagnostic box next to the batter(small square shaped box), take a piece of wire with the bare wire exposed on each end, and conncet the F/P to the GND inside the diagnostic box. Once connected turn the key to the on position and you should hear the fuel pump come on. You can also put your hand on the fuel feed line(Lower left when standing next to the driverside front wheel) and you should be able to feel the pressure if the pump is working.

Also check the EGI fuse which is in the rectangle shaped fues box attached to the positive side of the battery. I have blown that fuse before when a car had an electrical problem.

David

Yeah, the problem is finding all the fuses. Also, without the fuse puller, what is the easiest way to remove them?

BTW, I just checked and there are some more electrical problems than just not starting.
Headlights and flip motor work but Tail lights don't.
Dash lights are out.
Door chime is out.
No sound when the key gets turned just prior to cranking (I'm not sure what happens, but I've always thought it was the fuel pump that makes a bit of a noise as the key is turned to the on position? Now there is nothing but a very faint click.)
Turn signals are out.

Probly one of the main fuses on the drivers side iner fender, you might be able to see if its blowen. The fuses pull out pretty easy.

Pretty much all of the fuses are in black boxes in three locations: (1) in front of the intake, (2) next to the battery, and (3) in the driver footwell.

I checked them all except the Main 120A fuse. I finally decided to check it (although as near as I can tell if it was out not much would work). Unfortunately, I figured it just pulled out like all the other fuses. Now I don't know if it was really good or not, as I ripped it apart. Funny, I didn't know about having to under the Main fuse retaining bolt. Anyway, I now need to get another 120A main fuse. Any idea if a local Mazda dealers might carry that?

I've never had to mess with the main fuse, but have you checked with the local AUTOZONE etc?
There used to be a red plastic shroud/boot over that alternator terminal. As soon as you get things sorted out, you might want to get it covered again...electrical tape, self-fusing tape, something.

this sounds pretty much EXACT to what happened to me. i also grounded the AXACT same alternator wire. and i was having the exact same symptoms (the lights and stuff)

turned out i blew the main fuse (fuse box by the battery) and yes, it did have the two bolts on both sides of the box that hold the fuse in place.

so im just posting this to let you know that im pretty confident that this was causing the problems. (no need to worry if the fuse was really blown or still good.....it was probably blown)

Yeah, I was thinking the same thing. The tape would need to be able to take some pretty high heat. I suppose I can ask at an autoparts store and see what they might recommend.

auto part stores do not carry a big enough fuse. and I looked into why the alternator wire has power on it but i cant figure it out cuz it supplies power if anyone knows please share. but yeah I dropped my alternator once and it blew my big fuse luckly I had a spare harness lying around. Have you figured out yet that that fuse bolts in?

I can't offer any help with troubleshooting, but I can offer some advice.

Before you start working with the main fuse and the bolts that hold it down, disconnect the ground (negative) from the battery. That way, when you're working with the open end or socket and hit the chassis, you won't repeat your mistake.

There are a few heavy gauge wire spots on the car that are always hot. The positive on the batter, the alternator connection (you already found that one), and the starter solenoid are the main ones that comes to mind.

The local MENARDS hardware store carries this brand, but there are other sources, like McMaster Carr. If you've never worked with it...there isn't any adhesive, just a strip of silicone layered in mylar. Cut to length, peal off the mylar and wrap it around. It fuses to itself. Stands up to about 500 F. and insulates to about 4 billion volts. :) Good stuff.
http://img90.imageshack.us/img90/841...mbg7ev8.th.jpg

I sure hope your right and it makes me feel better knowing that my hunch about the main fuse may be right. It looked good, but after pouring through the entire wiring diagram, it seemed as if a bad main fuse was the only thing that could give me the symptoms I'm getting. It was also nice to know that I'm not the only person to have done something so, err... less than intelligent? :wallbash:

Just so I don't screw things up more than I have already, are these the bolts that I have to remove to get out the rest of the fuse (yeah it came out in pieces, you can see one of the blades still there in the picture) and put in the new one?

Looking at the Main Fuse box from the left
http://i95.photobucket.com/albums/l1...7/PICT0004.jpg

From the right
http://i95.photobucket.com/albums/l1...7/PICT0003.jpg

I was also wondering why that wire to the alternator was hot even when the key is off. Doesn't make sense to me.

I figured out about the bolts after I tried ripping the main fuse out with pliers. See the pictures above.:scared:

I'm going to be much more careful around the engine bay from now on. I've already disconnected the ground from the batter (I do learn, albeit slowly and painfully), and will disconnect the positive from the battery before I try loosening the bolts. Am I pointing at the correct ones in the pictures?

OUCH! I just found out how much that fuse is going to cost me. A bit over $90 with tax for next day service at my local dealer. I definitely don't want to blow this puppy again.

I'll look for it. I'm noticing a lot of similar problems under the hood where the wiring should be recovered.

The alternater wire is tied into the main power harness becouse it charges the battery and works best not interupted by a switch. Plus its cheaper to build!

get yourself a DMM(digital multimeter) or the test light tool from snap-on, turn your key on to pos 2 and check every fuse, if there is power at one side should be at the other side, if there is ground at one side there should be at the other side so on and so forth

also check the egi relay its yellow when i did this it was also blown.
another 75 bucks.

Any idea where to find out how to check the EGI relay? I'm assuming it must be in the shop manual somewhere....

you have to open it to check it.

You should be able to get another 120v fuse from someone parting out a car.

I too learned (thankfully not by breaking) that the main fuse has a retaining bolt.

Dave

Update
 

OK.... Not wanting to spend $90 on a fuse, I did some more checking. It turns out that there is another fuse that fits most Mazdas from '91 on. It is also a 120A fuse, but it isn't specifically for the RX7. It only costs $7.00. I bought two from another Mazda dealer who had them in stock and it only cost me a couple gallons of gas and 40 minutes of time.

I had a patient cancel just before lunch. I took off for the dealer, picked up the fuses, went home, installed the fuse, put all the parts back together that I had taken apart, connected the battery and she started up first crank. :)

Thanks to everyone for the great help and thoughtful advice. I really appreciate it.

Now I'm back to trying to remove that Greddy Oil Filter relocation kit without breaking anything this time.

fill us in on what fuse you purchased.

well yeah, if you havent gotten a reply about the bolts yet, those are the bolts you need to take out first. its ok, i also broke my fuse at first too. he he. i forgot to take out the bolts and just yanked the fuse apart (it was late, dark and i was having a bad day already).....the i took the screws out. lol

cant help you the where to buy the fuse, sorry. if you want i can buy one or two here and send them to you just in case. (i blew two fuses before i realized my mistake...dont ask, he he) you can keep them as spares if anything happens later on.

if i can remember they were around $3-$5 each.

Please give us specifics on this $7.00 fuse. That's a pretty big price break. It fit perfectly with no issues whatsoever?

If you got the fuse from Mazda, just the part number from the package will be perfect.

+1. An $83 discount and it fits? Might be worth adding this to the FAQ sticky thread.

Fit perfectly. Heck if it didn't, I wouldn't be smart enough to install it. I lied about the cost though, I bought two fuses and the total cost with WA state sales tax was $14.04. So each one cost me $7.02. Dealer list price is $6.45

Part number is #J001-67-099

The original fuse that I was quoted was part # JE 1618 811

http://i95.photobucket.com/albums/l1...7/PICT0006.jpg

"Before you start working with the main fuse and the bolts that hold it down, disconnect the ground (negative) from the battery. That way, when you're working with the open end or socket and hit the chassis, you won't repeat your mistake. "

The questions you are asking are of the lowest level basic auto mechanics skills.

Good auto mechanic skills should always be used while working with a shop manual on these cars, and all others for that matter. One of them is always remove the negative battery cable when working around wiring. Otherwise you will damage something or hurt yourself. Also you should replace any damaged parts with the designed OEM hardware. If you do not know how to properly work a system on this car I suggest you leave it for the pros at a Rotary shop.

Later

Thanks for the advice Tom. I'm always happy to read suggestions from fellow old farts.:)

I readily admit that I have little to no mechanic skills. As you probably know, there are many types of intelligences, mechanics being one of many. Sadly, I'm hopelessly deficient in that type of intelligence. Even so, just as many special Ed. kids can eventually learn to read, I am hoping that will lots of reading, practice, and a few mistakes, I'll eventually be able to manage some basic skills. I do have the shop manuals and have spent hours reading through them but will most likely always ride the short bus of mechanics.

I failed to disconnect the ground. I'll blame my inexperience. When I was trying to track down other electrical problems in the car, I had disconnected the ground. Since I wasn't working on the electrical system, I didn't think to do it in this case. Obviously a stupid mistake.

The fuse that I replaced it with is a Mazda fuse that Mazda currently specs as a replacement for the OE fuse. Apparently both are available. One is used on the RX-7 only, the other is used on multiple Mazda vehicles, including the '91 and later RX-7s (at least according the Mazda parts guy). I know that most folks on the forum have a lot of disdain for dealer's shops, but this is a fuse that their manuals would have them put in the '94 FD. I don't see a problem with this.

More good advice. I've already done that. Once I got the car home, the first thing I did was to take it to a local rotary shop that was highly recommended by folks in the NW. I'll be taking it back to him shortly for follow-up and additional work. I have no problems paying people to do things that are beyond my scope.

I'm almost 50. I'm an old dog trying to learn a few, basic tricks. I'll continue to do stupid things I'm sure. I'll probably also continue to ask stupid questions. Anytime you feel like offering suggestions or advice, I'll be very grateful to receive it.

Here's a suggestion:

When you plan on using tools under the hood, *always* disconnect the negative battery terminal.

I learned that lesson the hard way as well. Grounded the throttle cable to that same alternator bolt. Took less than a second to cut halfway through the throttle cable.

David,
I don't disconnect the neg. cable EVERY time I work on it. If you'd intended to disconnect any electrical components... fine, good judgement rules. Cover the terminal and be just be careful.
Kudos for willingness to learn and for spelling "Greddy" correctly. Everybody walked before they ran. Currently I'm at a slow trot myself and I've got a few years on ya in more ways than one. ;)
Search here with questions and issues and post up if you don't find an answer. Good luck with the car.

an easy remedy would be to get the rubber boot that covers that alt wire-bolt.

but yes you should disconnect the battery anyways.

Any ideas on where to find one? Is that something that I could find a generic wiring boot at a parts store or am I going to need to find a specialty part. It seems to me as if this type of thing would be very common in many cars so it shouldn't be that hard to find?

Just try the classifieds on this board. I found one for about $5 a few years ago.

1. 2. 1. You should be able to get a boot like that at an auto-parts store, or at someplace like a radio shack. The car originally came with one.

2. Don't feel bad. We "experienced" guys came about a lot of our knowledge learning from our screwups. I'd wager every one of us so-called "experts" has a multi-page list that we could write noting the stuff we've effed-up along the way. You have a good attitude, and are willing to learn. IMO, you're WAY ahead of the game.

Good luck, and have fun!

If you fancy hunting around junk yards there are plenty of Mazda's that still use them if you want an OEM and can't locate a suitable replacement. You were lucky in several respects, in some cases people have damaged there ECU and had to find one of those as well. For the time it takes to disconnect the ground there's no reason to "be careful" and leave it hooked up, there are other hot leads besides that one and you never know when you'll run across it.

a while after i did this to my car my motor went out, so after the year wait for a motor i took my car to the rx-7store.net to get the fuel system upgraded and they immediately noticed it was missing and replaced it for me.
not sure the price.

it should be fairly common thoe.:icon_tup: just a rubber boot.

I would bill that boot as a safeguard, not a remedy.

It's not too hard to accidentally push it aside with a wrench.

I agree with you. Still, I'd like the boot. :)

The OEM boot clamps on to the bolt assembly so would require quite a bit of savagery to move accidentally. Exposed live bolts with direct unfused connections to the battery are not a good thing. As I mentioned earlier, these boots are very easy to find in the classifieds here for $5 or so.

Agreed that it is a good thing.

As my car has one, and I still managed to short it to ground, I would say it is a remedy, and disconnecting the battery while under the hood is cheap insurance.

This post saved a broken man. I can't believe I was so stupid as to short my alt... especially as my battery has a kill switch! That's just laziness.

Thanks again guys :)

Hey don't feel bad for damaging your car, I have done it too. When I was fixing my power steering leak I didn't know what a banjo bolt was at the time, and I tried to line the hole in the bolt to the line perfectly when it really doesnt matter which direction the hole goes. It was so tight, I could have stripped the bolt doing that, but I didn't. I also grounded out my air pump wires, frying my ecu, all because I didn't disconnect the battery before the job 0ops! When changing spark plugs and wires, I dissasembled the TPS, and removed it from the car. BAD idea. I found out later by disassembling it (with it being so old) I had damaged it, and it had to be replaced and readjusted, another costly repair. Then again I have also done a LOT of jobs right without screwing things up: ABS pump, clutch master and slave cylinder, bleeding brakes, P/S pump, P/S pressure hose, and suction hose, Starter and rewiring, ECU etc. Learing from your mistakes, helps you to learn more about the what NOT to do lol

terminal boot
 

I have a spare engine,the main harness has been cut and of no use to me,if you pm your address i will send you the terminal boot .Its no use to me as i need a new harness for my spare engine.

Hey, that's a great offer thanks but I'm in Australia!

terminal
 

Well i dont mind, you can buy these from an auto store,if you want it i will post,£1 aint gonna break my bank.