possible electrical short
 

Hi, I'm having a problem with the electrics in my car.1986nate and I finished doing another 4.11 transmission swap on my car but now It's giving me problems. When I first test drove the car everything on the car worked except for the speedometer, minus the fact that it was starting of in 3rd gear. I stopped the car when I noticed the FWD light was on, shut the car off and removed the fuse. Once I turned the car back on my tachometer, warning lights, windows, sun roof, ac controls and radio stopped working. My turn signals, gauge cluster back light, power driver's seat and ac control back light still work. Nate had suggested that my speed sensor wire (which has no plastic plug socket, only pins) might have been put on backwards causing a short. I am in dire need of a running vehicle and any input would be greatly appreciated.

Thank you.

-Joe

Re: possible electrical short
 

Look for blown fuses and try unplugging the speedo.

Starting off in third gear means that there's a problem that the TCU knows about and it's bad enough that it's in limp-home mode. Check codes.

Re: possible electrical short
 

should probably try reversing the wires on your speed sensor and replacing any bad fuses first, it's possible that if the wires touched each other it blew the fuse for tcu and possibly others.

Re: possible electrical short
 

I can't check codes, my gauge cluster isn't working.

Re: possible electrical short
 

try plugging the the fuse back for FWD and see what effect that has on the short, maybe it will get some of those electrics working and start to narrow down the problem

Re: possible electrical short
 

I can see how that might be a problem...

Well first go through the fuses with a fuse tester. Can you post a pic of the speedo wires (or you can text it to me and i'll post it)? That is where I would first focus my attention.

Re: possible electrical short
 

Let me update this. First I will clarify that I did in fact do the differential swap on the transmission, helped bolt it up but figured Joe could handle the rest since he's done a couple trans swaps already. Thought it would be no big deal.

So in more detail, from the sounds of it, The car went from when he first started it up and took it for a test drive, everything worked fine but the speedometer. Tach worked fine, dummy lights all worked as they should, etc.
When he stopped and took out the FWD fuse, he lost tach, dummy lights, pwr windows and sunroof, climate control and in the time that I was able to come back over, the radio had worked but then stopped working. The backlighting on the gauge cluster and climate control still all work, however not the button on the end of the stalk that lights the clock and other stuff back to full brightness with the lights on. I know about the breaker under the driver seat but typically that knocks out the power seat as well but that still works as it should. If it can kill the sunroof and windows separate from the seat, that would be valuable information.

There were no blown fuses and inserting the FWD fuse back in made no change except that might have caused the radio to stop working when we plugged it in and unplugged it a little later. (Didn't notice the change in radio function right away as the volume was off and was not something of focus until it was not working. Also, all grounds appear to be fine. I was not able to look too deep into anything as it was very late, it was dark, and I was tired from a long day of doing other work as well. Also, I'll be the first to admit that I hate electrical issues and advised Joe to come on here as there are a few here that are well versed in the wiring and electronics of the SVX. Hopefully this can clear some things up and help get some more solid leads for him to check out.

Edit: Also advised Joe to leave the speedo wires unplugged for the time being and taped up so they cannot short out against each other. I do have another harness with connector from the junkyard for him to splice in that I will be giving him tomorrow so that this can't be an issue.

Re: possible electrical short
 

Nate, you left out the "starting in third gear", is that still the case?

Harvey.

Re: possible electrical short
 

Sorry Harvey,
I was not able to confirm or refute that it only had 3rd gear in forward positions as there was no exhaust on the car and it was after 11pm so testing it out would be sure to make some people very unhappy.

If it were starting out and only had 3rd gear, it would indicate a transmission electronic issue (code more than likely) that would be sending it into "limp home mode" or whatever other name there may be for it. Anything else that I can assist in any possible diagnosis I can help provide as far as symptoms. I tried to be clear as possible from what he told me from when he first was driving it, and things went haywire, to the things that happened when I was able to get back to him and try and see what was going on.

Re: possible electrical short
 

Do you know if the box that went in was a ' known good one',?

Harvey.

Re: possible electrical short
 

According to Joe, this transmission worked perfectly well and shifted well up until a blown front differential. We found an impreza in the junkyard that had a 4.11 and I purchased the front differential and changed out both the pinion gear shaft as well as the entire front case/ring gear and carrier assembly. So according to Joe, this transmission previously was in the car and worked as it should.

Re: possible electrical short
 

OK , he told me that is was, so we can write that off.
So it looks like the front sensor wires shorted and blew a fuse?

Harvey.

Re: possible electrical short
 

I very recently had an issue with a replacement front diff and valve body replacement.
After installing the front diff and valve body the SVX would shift up to third on the lift, but under way lock into third.
Naturally first I checked the internal transmission wiring connections,
(they were good)
then I checked the transmission ground, good as well.
Swapped back to the original valve body, no differance.:rolleyes:
Reinstalled the new valve body with the original solenoids,
same freeking thing.:confused:
By now the transmission had been in and out about four times, and the valve body about four times, Dave!:mad::rolleyes:
What I finally found was a broken wire hidden in the loom that goes to the transmission control wires on the left/drivers side of the transmission.
The break in the wires was an old one, but untill I had the trans in and out it USED to have good conectivity.:rolleyes:


Long story short, check the internal AND external wires next.

Re: possible electrical short
 

No fuses were blown that I could tell. I do not have a fuse tester with me, however I very closely with a flashlight visually checked (multiple times and specifically checked the radio fuse as well as a couple others that I thought could be directly related) all fuses both under hood and in the driver footwell and pulled out any that looked questionable and confirmed they were ok. It appears that things were still shorting out based upon the fact that when I first got to the car, the radio was still working, and at some point, it stopped working. No power at all to it, won't turn on when holding the power button on it, etc.

Re: possible electrical short
 

Has anyone came up with a possible solution to this problem?