speedometer trouble
 

im trying to buy a new speedometer for my 1989 gmc suburban but all the aftermarket places stop at 1987 when i ask them most say they have no idea if it will work in a 89 or not .
anyone know of a replacement that works or is the 1987 listed the one that works up to the 1991 body change?

Re: speedometer trouble
 

It may be that Chevy switched from cable over to electric. Not sure what year that happened but that may be the reason.

Re: speedometer trouble
 

Yes that's the reason. 89 is electric.

Re: speedometer trouble
 

88 is the last year of cable driven I believe. At least my 88 Suburban is cable driven anyways.

Re: speedometer trouble
 

my 87 crew cab is electric. did they use both?

Re: speedometer trouble
 

I thought 87 and up is electric, because they're fuel injected so the computer also gets the signal.

Re: speedometer trouble
 

My 87 was cable driven, but there was a speed sensor built into the back of the speedo. Then the wires went to the VSS buffer and then to the ECM since the truck came with TBI.

Re: speedometer trouble
 

Here's what I was talking about.
http://67-72chevytrucks.com/vboard/a...1&d=1284395943

Re: speedometer trouble
 

1989 was still cable driven so 1981-1987 will work. 1990 went to VSS driven because of the Rear ABS.

Re: speedometer trouble
 

THI is got the years right.

But it not unheard of the very late last of the run on the line having a few changed early to the new part some times when they short the old ones.