Speedo Question/Problem
Thread Starter
Intermediate
Joined: Nov 2001
Posts: 30
Likes: 0
From: Harleysville, PA
Speedo Question/Problem
A little background;
90 C2 (with build date 10/89) Removed stock non-LSD transmission and replaced with a 94 LSD equipped trans out of an RS.
The problem – new trans does not have a sender for the speedo, hence my speedo no longer functions. It is not that big of a deal since the car is primarily used on the track, but sometimes I would like to know how fast I am going and also I would like to pass my state inspection.
From what I can tell the factory began using the ABS system to feed the speedo in 91 or 92. According to the wiring diagrams there are two additional relays in the fuse box (#24 and #52) in the newer cars utilized for the speedo signal. #52 is identified as “frequency transformer for control unit” and I believe it functions by changing the signal coming from the ABS system to a signal acceptable to the speedo. Relay #52 is wired in my car but no relay is plugged in. #24 is not wired at all. My thought is to splice into the feed from one of the ABS wheel sensors (the factory used the front left in the newer cars) and transform this signal into what the speedo needs/expects.
This will be a winter project but I’d love to hear any suggestions from the experts out there.
90 C2 (with build date 10/89) Removed stock non-LSD transmission and replaced with a 94 LSD equipped trans out of an RS.
The problem – new trans does not have a sender for the speedo, hence my speedo no longer functions. It is not that big of a deal since the car is primarily used on the track, but sometimes I would like to know how fast I am going and also I would like to pass my state inspection.
From what I can tell the factory began using the ABS system to feed the speedo in 91 or 92. According to the wiring diagrams there are two additional relays in the fuse box (#24 and #52) in the newer cars utilized for the speedo signal. #52 is identified as “frequency transformer for control unit” and I believe it functions by changing the signal coming from the ABS system to a signal acceptable to the speedo. Relay #52 is wired in my car but no relay is plugged in. #24 is not wired at all. My thought is to splice into the feed from one of the ABS wheel sensors (the factory used the front left in the newer cars) and transform this signal into what the speedo needs/expects.
This will be a winter project but I’d love to hear any suggestions from the experts out there.