FC Electrical Help
 

Okay guys, I bought an FC today. It is a non-running 86. The motor has 20k on a rebuild, but it needs a tranny. Supposedly the car ran before, but now isnt running. It wont turn over, and does essentially nothing when you turn the key to crank. I assume it is an electrical problem, so any suggestions would be great since I don't know my way around RX7 world.

The under-hood fuse box has a blown fuse (the center black one that is bolted in). I am going to replace that, and see what that does.

Any advice or suggestions would be great!

Thanks,

Marc

Is it hooked up to a charged battery? lol sry couldn't help it :P
I had a short in mine once (light :-D) and the battery wouldn't hold a charge for shit tho... that was an unpleasant experience...
Make sure nothing is draining the battery, and replace that fuse - i don't know what it is for sure but like i said, it won't matter if there is something killin ur batt...

Is it hooked up to a charged battery? lol sry couldn't help it :P
I had a short in mine once (light :-D) and the battery wouldn't hold a charge for shit tho... that was an unpleasant experience...
Make sure nothing is draining the battery, and replace that fuse - i don't know what it is for sure but like i said, it won't matter if there is something killin ur batt...

One other possibility... ur sure there's nothin on the tranny thats screwin it up? If something over there is puttin more load than the starter can handle, or if its a bad starter....
And remember there is a starter disconnect on the clutch PEDAL... Mine is duct taped off so i can push start LoL

I did check the starter disconnect on the clutch petal, it looks fine. The tranny is screwed up, but I dont know how that would keep the car from cranking. The solenoid for the starter isnt even popping out, so it isnt that I dont think. The headlights wont come on either so I seriously think its an electrical problem.

The battery is good for sure, and has good power, and I had it charged today to full strength, so its not the battery.

Anyone else?

Wiring harness maybe?

Without the 80A MAIN fuse many of the car's electrical systems have no power, including the starting system. As long as the battery is charged and there are no other problems, replacing the fuse should get the engine started.

be sure to check the alternator upper terminal wiring, & make sure the nut is tight (not too tight- you'll break the stud!)...that particular wire/ terminal shorting to ground blows that main fuse in a flash...make sure the insulator under the terminal connection is in good shape...

Blew a 120 AMP fuse in that block. Going to check that alt connection now...

Alt connection is good. Other ideas?

Come on guys, please!

man, that fuse branches to a lot of things...does it blow as soon as you put it in? (key off)

Never upgrade fuses in an attempt to stop them blowing! That's just asking for an electrical fire. Find and fix the reason they're blowing.

I didnt know it was an 80. It didnt say, and that was the only size pep boys had.

It only blows the fuse when you try to start the car.

Short somewhere?

Okay, there is a definately shorted out connector to the left side of the guage cluster (where the headlight control knobs, etc. are)

Also, there is a connector not plugged in around the fusebox / cpu area, and there is also a two wire connector not connected near the ignition switch. Pictures of all are attached.

Looking at the fusebox, is anything missing from there as well?

(pictures are all attached)

http://www.ncula.org/rx71.jpg
http://www.ncula.org/rx72.jpg
http://www.ncula.org/rx73.jpg
http://www.ncula.org/rx74.jpg

NZC-don't the S5's have bigger than 80A mains? Anyway, 4SPresident, at least you know it's not the hot battery part of the circuit- it's through the ignition...if no other fuses are blowing, that narrows it down, too...are you SURE the alternator wiring is good? BTW, S4 or S5?

depends on what options you have on the car, for the fuses- you got the cover with the fuse names on it? Did you disconnect that burnt plug, or was it like that when you found it?

I disconnected the plug. S4 it is. Minimal options. And I am pretty darn sure the alt wiring is good...

is that the headlight switch harness? (the one that's burnt)...are the connector pins melted/ fused together?

yes, we are pretty sure that is the headlight switch harness...

well, there ya go- does the fuse (yes, it is an 80A) blow with the harness disconnected?

Well, so far we've got most of the interior lights to work (gauge cluster lights up, all parking lamps work, hatch lamp works, 2 small map lights on headliner work,etc) The dome lamp has a short in it somewhere, it sometimes works and sometimes doesn't. Also, when the dome lamp is on in the middle position, it makes the door lamp light up on the dash, but if we wiggle the wires on the dome lamp, the door lamp will go off.

Back to the starting problem, when we turn the key, absolutely nothing happens. It seems that nothing is energizing or getting power. Gauges that should work when the key is turned on (such as the Voltage gauge and the fuel gauge) don't move at all. Nothing under the hood sounds like it is getting power either and I can't hear the fuel pump come on either.

I can see that this is going to get quite frustrating.

Wayne88, we'll try it that way and see what happens. Let ya know in a bit.

1. The alternator wiring is good if the fuse does not pop until you turn the key to START.

2. The burnt sockets on the light switch ain't too pretty. I'd a thought the Meter fuse would blow befor the main. I doubt that is the problem with the main fuse blowing.

3. I'd leave that burnt plug off for right now. Then since you seem to know about the switch on the clutch pedal (InterLock switch) and how it relates to the starter....pull both connectors off that clutch switch OR pull the small wire off the starter and then try a new fuse and go to Start. If the fuse does not blow its the starter/wiring to the starter that has a dead short.

dome light doesn't have a short- it's just crappy switch contacts (unless you're blowing the ROOM or ILLUM fuses, too)...yeh, that 80A fuse feeds a lot of stuff- it's no wonder you're not getting much when you turn the key with it blown

yeah...the dome light is iffy, but by the same token so is the door idiot light on the panel.... Gonna call it a night... no parts stores are open to buy than 80 amp from, so gonna wait till tomorrow and buy a few. PLEASE, anyone else chime in... I would LOVE to get my new little FC running....