Electrical questions regarding radio fuses

pablo94sc · 12-18-2009, 06:52 AM

Hey everyone, I'm looking for a quick clarification on the fuses used for the radio in an '89 MKIII (automatic) with a 7M-GE engine. Between an my Haynes manual (no specific wiring diagrams for 87-89 models) and an electrical diagram for a '90 model I found online, I'm at a bit of a loss.

Anyway, according to the Haynes manual I have, the '89 only has a 7.5A fuse for the radio while the previous years had both a 7.5A fuse and either a 15A or 20A fuse in the junction & fuse boxes (DS kick panel). Does the DOME fuse (20A) tie into the harness for the radio as well (seems to be in the same location as the previous years RADIO2 fuse)?

Reason I'm asking is there is a ground short somewhere in this car that is causing the speakers to crackle intermittently, and continues to do so after pulling the 7.5A radio fuse. This also failed to activate the anti-theft code in the radio, so makes me pretty sure there's another circuit I'm missing.

One more question... the wiring diagram I have for the '90 appear to show a common ground setup for the car, but the speaker wiring seems wrong. This car has the 6 speaker setup, but no rear sub(s) as the wiring diagram implies. What am I missing here?

Thanks for the help.

Paul

PS: Car has been in the family since new. I'm inheriting it and would like to make it road worthy again.

cre · 12-18-2009, 07:21 AM

Yes, two radio fuses: 20A Radio No.1 and 7.5A Radio No.2. No.2 is in the Driver's side kick panel fuse box and No.1 is in the engine bay fuse box.

20A Radio No.1 == 20A DOME.

The subwoofer was optional starting in '89 or '90.

I'm looking at the charts for '88 right now.

pablo94sc · 12-18-2009, 07:42 AM

That's what I needed to know and gives me a place to start. Thanks!

Paul

PS: This wouldn't happen to be a known issue, would it?

cre · 12-18-2009, 07:56 AM

Nothing common... I'm sure it happens to more people than just you though.... but not many.

Best of luck with it! If you need more data let me know.

12-18-2009, 06:52 AM	#1
pablo94sc Stock Join Date: Dec 2009 Location: TN Posts: 3	Electrical questions regarding radio fuses Hey everyone, I'm looking for a quick clarification on the fuses used for the radio in an '89 MKIII (automatic) with a 7M-GE engine. Between an my Haynes manual (no specific wiring diagrams for 87-89 models) and an electrical diagram for a '90 model I found online, I'm at a bit of a loss. Anyway, according to the Haynes manual I have, the '89 only has a 7.5A fuse for the radio while the previous years had both a 7.5A fuse and either a 15A or 20A fuse in the junction & fuse boxes (DS kick panel). Does the DOME fuse (20A) tie into the harness for the radio as well (seems to be in the same location as the previous years RADIO2 fuse)? Reason I'm asking is there is a ground short somewhere in this car that is causing the speakers to crackle intermittently, and continues to do so after pulling the 7.5A radio fuse. This also failed to activate the anti-theft code in the radio, so makes me pretty sure there's another circuit I'm missing. One more question... the wiring diagram I have for the '90 appear to show a common ground setup for the car, but the speaker wiring seems wrong. This car has the 6 speaker setup, but no rear sub(s) as the wiring diagram implies. What am I missing here? Thanks for the help. Paul PS: Car has been in the family since new. I'm inheriting it and would like to make it road worthy again.

12-18-2009, 07:21 AM	#2
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Yes, two radio fuses: 20A Radio No.1 and 7.5A Radio No.2. No.2 is in the Driver's side kick panel fuse box and No.1 is in the engine bay fuse box. 20A Radio No.1 == 20A DOME. The subwoofer was optional starting in '89 or '90. I'm looking at the charts for '88 right now. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

12-18-2009, 07:56 AM	#4
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Nothing common... I'm sure it happens to more people than just you though.... but not many. Best of luck with it! If you need more data let me know. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

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12-18-2009, 07:42 AM	#3
pablo94sc Stock Join Date: Dec 2009 Location: TN Posts: 3	That's what I needed to know and gives me a place to start. Thanks! Paul PS: This wouldn't happen to be a known issue, would it?