91diesel

I've started 2 threads here, one asking about my windshield wipers not parking and one about my speedo not working. So here's the deal. I have a 91 pickup truck that I swapped in a 3.0L turbo diesel along with wiring harness and complete drivetrain. Although this sounds really iffy it would be no different than if you swapped in a 3.0 (or maybe a 3.4) V6 in place of a 22re and changed over the wiring harness and ECUs. So everything works great except my windshield wipers and my speedo. Today I made an interesting discovery that correlates the two. I got my windshield wipers to come on lo and high after replacing the fuse (still no int and they don't 'park'). When I left the driveway today the speedo worked for about two blocks then died. (usually I'll get some bounces out of it but no steady speed) I thought nothing of it until I tried out my wipers. The wipers didn't work but when they were on high or lo the speedo worked perfectly, I tried it for several miles and as long as the wipers were on (not int though) the speedo worked great. Now the wipers were not actually working though, only the switch was on. I'm sure if I look at the wiper fuse it'll be blown again. Any ideas? bad ground somewhere? (I've hooked up 3 or 4 from the dash harness. I should mention that I swapped in the later model electric speedo and dash, and the only other weird issue is that the motor came out of a 4 runner so the wire plug for the A/C amplifier (that is what the rpm control knob is right?) had more wires and was different but I matched up what I thought would work. OK long post, thanks for any help tracking this down.

ulfr

From what type of truck are the electro cables? Land cruiser 90/120 series?
What type of engine is it? 1KZ-T or 1KZ-TE? There is a huge difference between electro stuff on those two engines.

I'd think the problem lies in that the speedo is gettin' ground through the wiper switch, prolly blowin' the fuses for the wipers along with it.
I'd check all the plugs and ground and see if everything is hooked up correct.

91diesel

It's a 1KZ-TE. All the guages, tranny, transfer case, wiring harness, etc is out of the diesel surf (4runner). I think maybe the VSS is using the ground from the wiper motor. I tried running an alternate ground to the pole marked 'ground' on the back of the gauge cluster/speedo but that had no effect. Anyone have any good schematics on the VSS?