[Riggs]

Hey Guys,

Everything was fine with my car until today when we changed out the radiator with a new Koyo Unit and replaced the stock fan with (2) Flexalite fans....

Now everytime I turn the ingnition to the "on" position, the EFI fuse blows in the engine bay fuse box...(30 AMP) fuse...

A few times today I have been able to drive it about a mile, and then it has blown and left me stranded on the side of the road....

This has happended a few times today....and I'm frustrated....

The only thing I can think of is bad ground, but I dont know what I might have done istalling fans and radiator that could have messed something up...

Any ideas? The car is currently in a Kroger's parking lot....

 

[quick]

Put the stock fan back on. It's better anyway. I suspect that will solve your problem.

 

[Riggs]

The guy that had the car before me had installed a cheap $40 single 16" Autozone fan....

So, this is quite an upgrade....

Still looking for advice?

 

[quick]

Still looking for advice?

When you fuck up the wiring on your car and cause shorts that blow fuses the best way to fix it is to remove the wiring you performed and examine it to ensure that you do it right the next time.

Get a voltmeter and start checking stuff out. If you aren't sure how to do this then get ahold of a friend that can teach you or get an electrical book that will walk you through the steps.

 

[supra400hptt]

Sounds like you tapped the power to the fan on the same circuit that is blowing. Where did you get power for the fans?

 

[Riggs]

No, I wired up the fans straight to the battery just to get home... I was going to install the relay when I got there...

It has nothing to do with the fans, as they are currently unplugged...

 

[quick]

So has this always happened then? ...or only after the fan install?

Sounds like you may have pinched/cut a wire...? Get a wiring diagram and trace things and examine the wires.

 

[Jarrett H]

More than likely you have an open to ground. A short is when two wires touch, open to ground is when an exposed wire is touching a ground somewhere. Look at repair manual and figure out what objects are on that circuit and you can easily trace the problem down.

 

[Riggs]

Anybody wanna share a wiring diagram?

Or even better yet, is there a place I can download the factory service manual?

Thanks....

 

[Jarrett H]

I know mkiv.com has them.

 

[supra400hptt]

http://www.mkiv.com/manual/

 

[Riggs]

Guys, I'm not a electric chart specialist, lol....

Anybody wanna take a stab at what else is on that circuit so I'll have some places to check?

Thanks...

 

[93dawg]

Guys, I'm not a electric chart specialist, lol....

Anybody wanna take a stab at what else is on that circuit so I'll have some places to check?

Thanks...

To start out with which EFI fuse is blowing? No 1 or No 2???

PM me with your email address and I will see if I can get you started off in the right direction. I will be gone most of the day though from about 11:30 AM PDT...

 

[quick]

Guys, I'm not a electric chart specialist, lol....

Well so unfortunately if you own a modified car you have two choices: pay someone money to fix it, or take some time to learn to fix it yourself.

Electrical diagrams are actually pretty easy to read if you take the time to puzzle it out. Start off by looking for the fuses by the names on the fuse box. Then start tracing stuff from there.

Think of this as a great opportunity to learn about a subject that will always be useful to you.

Good luck, man.

 

[SUPER-MKIV]

From what I know there's only two things that can cause your problem. One of your problems could be a short to ground which means there's barely any resistance (alot of current draw), so your fuse will blow. The other problem could be that your fan/s need more than 30A in order to work.

 

[Riggs]

Okay, here's the deal....

The fuse only blows whenever I turn the ignition to the "on" position....

I unplugged the fans, SAFC, and Greddy Profec E01 to see if it was some sort of current draw problem....

fuse still blew...

What else is run off of the EFI fuse? The same 30 AMP fuse that controls the ECU...It's the second 30 AMP fuse down in the engine bay...

 

[93dawg]

Okay, here's the deal....

The fuse only blows whenever I turn the ignition to the "on" position....

I unplugged the fans, SAFC, and Greddy Profec E01 to see if it was some sort of current draw problem....

fuse still blew...

What else is run off of the EFI fuse? The same 30 AMP fuse that controls the ECU...It's the second 30 AMP fuse down in the engine bay...

Look on cover of the fuse box and tell us whether it is the #1 EFI or the #2 EFI fuse that is blowing out...

 

[Riggs]

Okay, the EFI 1 fuse keeps blowing...

Following the advice of a local Supra owner, I pulled the "EFI Main" Relay in the fuse box...

the EFI #1 fuse didnt blow with the relay pulled, but as soon as I plugged the relay back in, the fuse blew...

What all is controlled by the EFI Main Relay?

I thought perhaps the fuel pump, so I pulled the connector in the trunk (one that sits in the wheel well) that sends the power to the pump.....fuse still blew when I turned the ignition to the "on" position.... this leads me to believe its not the fuel pump..

I really appreciate your help trouble shooting....as I'm out of ideas...

Thanks...

 

[supra400hptt]

If you look on page 56/57 of the electrical manual, wipers, turn signals, ecu, heater, gauges and rear window defogger relay all source power from EFI #1. Only thing is they all have seperate fuses that should blow first if there was a short downstream. You're probably going to have to take it to someone who's good with electrical. The black/yellow wire off of the EFI #1 needs to be checked for a short. There is a chance the relay is internally shorted. Swap in one of the other relays and see if the fuse still blows.

 

[mav7]

So if I understand correctly, your car was running great until you decided to install the flexalite fans & the radiator? Now, the EFI#1 fuse blows even when the flexalite fans are unplugged?

Start with the basics, how was the old autozone fan wired? On my stock radiator, I have a 2-pin connector that plugs in towards the bottom on the drivers side. I am not quite sure what this sensor is for, engine coolant temp possibly? Anyway, what did you end up doing with that connector with the new radiator?

Like Quick was saying, go through every wire you touched because the problem will most likely be there.

Good luck
-mike