1989 Mge A/T non- turbo, 7.5 fuse in Driver's kick panel is reading 13 amp output

[Donna Lyle]

Hi, new to Supra's and auto electrical, so please be patient w/ me!

I am having an electrical problem, replaced a blown fuse to the Instrument panel, (Power Windows, heater A/ C, Temp, oil pressure gauges, check Coolant, engine and oil lights, back turn indicators, etc.)

The transmission also does not shift automatically now

I replaced the fuse, and it immediately blew again. I tested the circuit and instead of the 7.5 amps for this fuse, it reads 13 amps.

I checked all the other fuses, engine compartment links, and can not find the problem.

I did discover after removing the dash, that the check engine and oil light bulbs had been removed (prior to purchasing the car, and mentioned if may be relevant to issue).

I can not figure out where else to look, all connections seem intact, and everything else is still working.
Any possible solutions greatly appreciated!

Thanks!

 

[Black Cat]

First off how are you measuring the amperage of the circuit?
Is this the 7.5 amp gauge fuse, if so look at the TSRM online.
Find every thing related to the circuit and unplug one thing at a time
till the amperage comes back in to spec, the device you unplugged
has some kind of short in it.

 

[kamiden]

Mine is doing something similar; evertime I turn on the Ignition the ING 7.5A fuse blows. I took out my radio and it doesn't blow now, but now it cranks but wont start. I can't get any diag codes to work so I have no idea what's going on now.

 

[jetjock]

The radio has nothing to do with the 7.5 ING fuse. It does have something to do with the 7.5 Radio fuse though. Neither have anything to do with cranking. Since we're apparently supposed to guess what "I can't get any diag codes to work" means I'll give it a shot: if the MIL doesn't come on with the key that's why the engine won't start...

 

[kamiden]

I read up on how to jumper the diagnostic box pins (i.e. T1 to E, 12v to FP... etc) and those will not give me any type of spark when trying it with both wire and paperclip, nor does it give me a check engine light at all. Like the other gentleman, every time I would turn the key on it would immediately blow the 7.5 IGN fuse under the drivers' kick panel. I d/c the radio harness and it doesn't blow the fuse now, and that could have simply been coincidence I guess. Regardless I can crank the engine, but it wont start anymore (I replaced the 100amp fuse under the hood as well that had been blown as well). Everything was running fine until my battery went dead one day.

 

[jetjock]

Again, if the check engine light does not come on when the key is switched on (past accessory but before the start position) odds are the ECU is not receiving power. That can be caused by the IGN fuse or EFI fuse, among other things.

 

[3p141592654]

If the 100A fuse blew, then a battery hooked up backwards is a distinct possibility. Presumably happened when you replaced the battery last. In that case, you've got some work ahead finding all the fried components.

 

[kamiden]

That's the strange thing, the battery was hooked up as it had been since I bought it, all I did was jump it.. and yes the cables were on right. What's strange though is the positive cable cover should typicall be red and it's not, like maybe at somepoint someone replaced something incorrectly. <sigh>

 

[3p141592654]

Well, a 100A fuse doesn't just blow, there must have been a reason, and the usual one is a polarity mixup.