‘87 TR fuse blows after honking horn a few times - bad compressor?

Checked the amp draw when you activate the horn? And yes, look for a short.

 

Fuseboard tend to be very faulty on tr’s. Hopefully u have just a short; but if not ur mechanic can sort it out without too much of an expense. Several posts of boards here have been posted which can help u diagnose


Sent from my iPhone using Tapatalk

 

For maintenance remove the top cap and add a few drops of light machine oil occasionally to lubricate the bore. It should spin more freely and possibly not draw as much power. Simple system.
Image Unavailable, Please Login

 

302Tim.......good lord, he has the pictures.

 

Great Tim !

This shows why WE ALL should make pics of all our maitenance …: to showall our (future) followers who will face the same problems.

Hope it is a simple maintenance problem.

Is there not a plastic notch on the compressor in which you should put some drops of oil ?

BTW, if I recall well I made a seperate relay for my horn in the 512TR; oem wire activated that relay …

I wonder why I did that (Front bumper removed here … extra two relays for the headlights and one for the horn)

Image Unavailable, Please Login

 

Mel, on the Testarossa no way to add oil without removing the top (but it's just 3 screws)

 

U give the most detailed and best advice! Very valuable to us tr lover!!thanks


Sent from my iPhone using Tapatalk

 

Friend Tim Xplodee,

How did you cope with that fuse / horn problem ?

 

Oil can be added at the air hose nipple at the compressors that feeds the trumpets (in my experience with fiamms). . Back door so to speak. That’s the way I have always oiled the comprssors and a dry one can cause fuses to be blown from the strain to run.. You may detect a weaker sound or delay in spool up when it’s getting dry.

 

I'm guessing you are heading towards the solution--good luck!

 

Sounds like you are on the right path, but one other thing to do if you still have trouble would be to try a different ...113 relay in the relay A position for the horn. It's wired such that the 20A #1 fuse provides +12V power to both run relay A and the horn motor (so if something goes bonkers inside relay A itself that could also cause fuse #1 to blow). Additionally, that same "always +12V line" from fuse #1 goes to run the stuff in the glove box, including the auxiliary power socket, and it wouldn't be unheard of for someone to have used that same wire as a convenient always +12V source for running something added like an alarm system, power amp, etc.. Anyway, just wanted to point out there might be some other issues.

 

It should be a 15A minimum IMO (and 20A would be no sin) -- here's the F documentation references that I have for the TR fuse #1 rating:

TR WSM 330/84 (covers early euro TR) = 15A
TR OM 344/85 (covers early euro TR) = 15A
TR OM 451/86 (covers 1987 US TR) = 15A
Late euro wiring diagram 459/86 = 15A
1986-1987 US TR wiring diagram = don't have a copy of this
1988-1991 US TR wiring diagram = 20A (this also has the seat belt buzzer function so don't know if they increased it for this, or just bumped it up a little as they thought 15A was marginal)

Do you have any evidence for it being 10A, or is that just what was in there?

 

1986-1987 US TR wiring diagram = don't have a copy of this

This is listed as a 15A fuse (WD 457/86)

 

Thanks for the information. I always trust the specific wiring diagram book for a particular year/model/version the most (more than the OMs which don't always get updated well), but, if the label on the inside of xplodee's fuse-relay panel door says "20A", must have been something they missed in making the 457/86 wiring diagram book, or was such a late design change that it didn't get incorporated into it. That's the type of fix I like -- simple. Toot on!