93 Peecup speedometer problems - Toyota Nation Forum : Toyota Car and Truck Forums

PurplePower · 06-24-2010, 09:59 AM

I have a 93 Toyota PU 4x4 5 speed manual. 150,000 miles and rock stock. The only mods I have done are some fender cutting to cut off some cancer.

My fuse panel/junction block no. 1 got wet due to corrosion of the DS front fender and I had to replace the fuse panel and a couple of the electrical connectors after a small, but not minor fire. I took great pains to label and take pics of how everything came apart/went together so I'm pretty sure I got that right. The truck sat for about 6 months while I tracked down parts and information. After getting everything put back together I fired it up and everything seemed to be working correctly. On the first test drive I notice the speedometer bouncing around. Also, while sitting parked it will jump up to 60ish mph and the odometer will start racking up miles....mostly when I rev it up a little. Sometimes it will do nothing....just reads zero. Don't know if my electrical fire has anything to do with the speedometer problem, but I never had issues with the speedo before.

Read a few posts with similar issues but didn't find a solution. Anybody get this figured out? Ideas? Thanks for any help!

***Jayota*** · 06-24-2010, 02:04 PM

Its very possible it could be related since 93 is when they switched to the electronic speedometer in the trucks (only 93-95).

Best bet would be to find a wiring diagram and find out if anything related to speedo is near where your minor electrical fire was..

If you google search you can find the 1993 toyota FSM, but It doesnt have the fold out wiring diagrams that come in the manuals.

***fourwd1*** · 06-24-2010, 08:36 PM

Maybe check the wiring for the speedo sending unit, from the t-case to the cluster.

PurplePower · 08-05-2010, 08:49 AM

Still haven't figured this speedometer problem out. I took the junction block / fuse panel out again and rechecked what I had done before and didn't find anything wrong. Question: Does anyone know where I could find info on what all the different wires running out of the junction block / fuse panel all do? My haynes manual doesn't show this clearly and the online FSM doesn't either....

Also, I now noticed my 4WD is not working. When I shift it into 4WD I hear the electric "click" under the dash but the light on the dash does not light up and it definately is not in 4WD.....found this out when trying to pull my boat out the water...that really sucked! Any suggestions?

Thanks for the help....

PurplePower · 08-06-2010, 10:02 AM

Checked out the vacuum lines last night and found what appears to be a rust hole in the vacuum canister which is mounted in the passenger side front wheel well. Bad spot I think! I would assume this would make the 4WD (A.D.D.) not operate as it should? Can I bypass this or do I have to replace it? I don't quite understand its function in the system.