Speedometer and Cruise inoperable - after changing the radio?

[astronot]

Hi all,

I just got a 97 venture with about 90k miles. Of couse the first thing I did was try to put the factory cd player from my 95 astro in it. There was nothing surprising in the transition (except the mounting) - the harnesses matched up, etc. Driving in to work this morning I notice the speedometer isn't working, along with the odometer and the cruise control it appears.

First I though maybe I shorted a wire or something, but the only wiring around the radio is for the climate control panel, and nothing is really in the way or worn there.

Then I though maybe it was a fuse because I was too lazy to d/c the battery when I swapped the radios. I can't find a fuse in the main block (passenger side under the hood) that I can say for sure is for this stuff, and I'm not familiar enough with this vehicle yet to know where any other fuses could be.

Any help would be appeciated.

Thanks!

[astronot]

In troubleshooting this issue, I pulled the cd/radio from the astro back out from the venture, and with nothing connected the speedo/etc work again. Why would a radio, when connected, interrupt the function of these components?

[DRW1000]

Originally Posted by astronot

In troubleshooting this issue, I pulled the cd/radio from the astro back out from the venture, and with nothing connected the speedo/etc work again. Why would a radio, when connected, interrupt the function of these components?

I don't think it should interfere at all. I just replaced my factory stereo in my 99 and I think your wiring should be similar. The only thing that is related to the dash wiring wise are the dimming lamp wires. When installing an aftermarket market these are left unconnected. In your instance they may be connected to something else through your astro stereo. These should not affect the operation of your speedo but who knows?

[GregA]

Without looking at the wiring & connector diagrams, my guess would be that between 95 & 97, they changed the connector wiring to the radio a bit.

I will see if I can find the differences, but I would guess that either a Vehicle Speed Sensor signal or a Serial Communications signal is being shorted to ground or power by the old radio.

Does your 97 radio have the "feature" where the volume goes UP as you go faster? I believe this is called "Auto-Volume" (or something like that).

I will let you know if I find anything, but my documentation is pretty slim for the older models.

Take Care,

[GregA]

Well I couldn't find anything specific on the 95 Astro or the 97 Venture, but on a 98 Venture, one of the connectors pins DOES have the speed sensor signal going to it. Here is what I found for Connector # 2 (Gray)

Pin Wire Color Circuit No. Function
11 Not Used
12 BLK 906 RSA enable out
13 LT GRN 1011 RSA In
14 DK BLU 1796 Steering wheel controls input (Pontiac/Oldsmobile)
15 DK GRN 835 Data link
16 DK GRN 389 Vehicle speed sensor (VSS) (Chevrolet/Oldsmobile)
17 LT BLU 115 Right Rear liftgate speaker return
18 DK BLU 46 Right Rear liftgate speaker feed
19 YEL 116 Left Rear liftgate speaker return
20 BRN 199 Left Rear liftgate speaker feed

Notice Pins 15 & 16.
I would try to pull them out of the connector, one at a time (starting with 16), and try it again. If that works, put some tape over the loose pin, plug the connector in, and you're good to go!

Take Care,