Hi everyone,

Can anyone definitively let me know where the speed buffer relay is located on a NAS 1995 RRC? The part number is PRC 8882. I've seen some posts finding it in the pass side footwell kick panel but that was an Aus site, so not sure if it's different for LHD. Some posts say it's a big white relay and that what it looks like on ebay, can't find a white one to remove anywhere in mine. All I got from RAVE was the attached pic which hopefully someone can explain. Is it a green and yellow wire going to fuse X190(the speed buffer relay)? But where does this wire start?? As you'll see from the tabs open in my screenshot, I'm not an electrical expert. Hopefully take old one out - put new one in. I do have a volt meter but without explicit directions it might as well be written in Greek.

The reason I'm looking for it is the speedo, along with the odometer have stopped working. They went wacky up and down for about a week then stopped working all together. Started hearing some short circuiting crackles from under the glovebox on and off after about 15 min of driving. Then the truck started stalling when coming to a stop, which I have read is the computer not knowing how fast it's moving and messing up the fuel delivery. I've replaced the VSS with no improvement.

As I said I'm no electrical engineer and am hoping this little relay will solve a headache tracking down a wiring issue.

Any other ideas??

Cheers!

 

So apparently the buffer is inside the speedometer on a 95. This test D will let me know if I need to find a fault in the Green Yellow wire or the Black Red one, or hopefully not the speedometer or instrument cluster is bad.

Still wondering if any ideas about crackling shorting sounds affecting this from under glovebox.

 

OK, IIRC, PRC8882 is under the passenger seat. Remove the outer seat frame cover and you should see it there. PRC8882 is for adjusting ride height in the EAS system. What it sounds like is you have a bad VSS or vehicle speed sensor. That component is located on the transfer case under the car not anywhere in the interior. The clicking sound you're hearing from under the dash in the passenger footwell are relays that are clicking open or closed.

 

Thanks for your reply Paul, attached you will see the underside of the pass side seat - no sign of the relay. I'm thinking it must only be on pre 95 models. I did the test D outlined in the RAVE (raise vehicle, meter on speedo multiplug 2, spin drive wheel, no alternating voltage) pic attached earlier and it failed which leads me to believe it's a bad wire. Now just to find where.....

I know the relay opening and closing click sound and what i'm hearing is definitely short circuit crackling. I think it's a separate issue now, if I press the AC button it goes away, push it off it comes back. Also temp gauge creeps up in hotter weather as if fans are not coming on?