Adding junkyard elect speedo to OEM cluster

[Mac]

The S-10 T5 trans I put in my `63 Chevy C10 is elect speedo sender so I'm wondering if I can graft the head from a junkyard elect speedo into my cluster (repop of an OG)?
Naturally I would want a unit with similar sweep degrees and number graduation. It looks like this `92 S-10 / Blazer speedo would work and should be sender compatible with my trans. I'm guessing other GM speedos from that basic generation would be compatible, no?

Also, would it be any more involved that providing 12V power?

[wayne petty]

there is another slightly different version of that with a tachometer where the gas gauge is.. and the gas gauge gets moved to the lower left as i recall..

there are  a bunch of little motors to drive things backthere..

were you able to get the electrical connectors from the donor truck???

that will make it a lot easier to hook up..

this seems to be a tutorial on a similar swap..

this seems to be the print version of the same info shown in the video

http://www.s10forum.com/forum/f135/92-s-10-gauge-cluster-upgrade-what-are-my-options-516981/


i can look up more info.. but there seems to be a lot already covered..

[Mac]

Wayne, I should have been more clear. My plan was not to transplant the whole cluster but to use the S-10 speedo for it's guts to provide a red needle behind my OG Chevy face.

If you look close at my Chevy dash pic you may see that I cut matching "windows" where the Gen and oil press. idiot lights are, then mounted gauges on the backside to display thru the "windows".

I have not bought any donor cluster yet, still just dreaming it up. The 92 S10 unit in my pic looks like it has an analog odometer so I guess that would account for one of the motors you see on the backside. Ideally I could reposition the odo display to be centered in my cluster not offset like it is in the S10.

[Crosley.In.AZ]

some where in those years of speed-O  design (late 1980's  to early 1990s), there was a device called a DRAC  used in the dash.  It took signals from trans sensor and made sense of the signals , then fed those signals to the speed-O


That all changed when GM installed the metal reluctor ring in the trans.  40 notches on this disc

[Mac]

Yeah Tony, It's stuff just like that I am afraid of. Some sensor data routes thru an ECU or chassis computer first on modern cars, doesn't it? (Modern cars ....HA...and I'm talking about stuff that's now over 20 yrs. old)

I have a 91-92 T5 trans. Hey, I'll stick the guts from a similar year speedo in my cluster, add 12V...... BANG ZOOM.

Maybe not that simple?

[GPster]

This is only to help you narrow down S10 (S15?) years. The S15 that I'm re-bodying wilt my Jeepster body is an '87. Because it has a 2.5L engine that is TBI I've gone to trouble of getting the factory wiring diagram. It has a conventional drive speedometer off a TH700-R4 that is not electronically controlled. For '87 there is no difference shown in the wiring between transmissions but by the number of wires heading from the speedometer to the computer the speedometer is sending signals to the computer for control of the TBI and the engine's ignition (and cruise control). At least I can tell you you're going to be looking at something newer than '87. Have you thought that even if you find a speedometer that you can make work that it's going to be programed for the S10's (?) tire size and rear end ratio? It seems to be easy to find pieces to "dial-in" a mechanical speedometer. Before he went to Las Vegas Frank was talking about being surprised how many 5 speeds he had laying around for pieces or to be      re-built. Maybe he can come up with pieces or ideas how to make your transmission talk to your truck's speedometer. GPster

[Mac]

Yeah Joe, guys swap on the earlier mech speedo drive T5 tail housing  and then carefully position the drive gear on the output shaft with shims, pins and JB weld. Those early housings are now sought after and bring money. I ask Enjenjo, back in his posting, if he had any. No dice.

It looks like the DREC  ........err I mean DRAC modules (digital ratio adapter) are coded for different GM vehicle applications  and that determines speedo calibration for tire size, etc. Seems you can swap "jumpers" around  in a module to alter the ration, too.
A late 80's-early 90's C1500, manual trans, DRAC module might be a better way for me to go. Assuming the senders are the same; no T5's in 1500's.

I'm larnin.