Can anyone help with my speedometer ?

[modular93fox]

heres the oversimplified solution to all problems in the ...
get a 88-91 suburban inst. cluster with elec. speedometer. you cannot just snatch the speedo out becuase the PC board is different, and the housings are different. i myself have 2 and both are for sale 65+shipping. a very very simple repining of the factory inst. cluster harness and your all set. connect the VSS signal from the computer to the #18 pin of the connector, and call it done.
as far as the temp, autometer makes a probeless water temp sender, and adapter for the ls motors. it reads a tad incorrectly (15*) but whatever, im thinking of just taking the needle off, and resetting it by hand, or even trying to play with resistors.
autometer 2277 is the adapter
autometer 2259 is the probless. you dont want probe syle becuase it doesnt fit in the adapter, you would have to bore it out (becuase we did that to my friends swap), plus automtere asured me it reads the same.
anyway thats the solution to your problems and they are all cheap to get/do
clint

[pmcarbuilder]

I need to know the pin out where #18

is on the cluster

[88stepside]

http://www.ebay.com/itm/1989-Chevrol...b7f563&vxp=mtr

I have one of these for my 1988 and it will answer all your questions about your entire electrical system. I built my entire harness (excluding basic functions on left side of firewall) from a GTO harness and when anyone asks how I did it, the answer is always the same," One circuit at a time".

88-91 does NOT have DRAC, they have a similar module IN the cluster. The cluster NEEDS to see a 40 pulse per driveshaft revolution AC signal, that's why the VSS sensor ring has 40 teeth in an automatic transmission. Be glad you don't have to deal with A T56 and 17 tooth VSS.

[88stepside]

However, your PCM is capable of generating the proper signal for your current speedometer, though you may need to get the PCM flashed to get it to send the data out as stock it goes through the GMLAN connection to the instrument cluster.

Unfortunately, it's not. 88-91 goes Purple and Yellow twisted pair from VSS straight to back of speedometer cluster, 92 and later the VSS signal went to PCM or DRAC first and then to speedometer cluster. LS1 PCM will produce a signal like a DRAC, so for 92 and later it could be used to send signal to speedometer cluster.

Clear as mud?

[88stepside]

I don't a pin 18 on mine.