Volvo 5.0GIPWTR Chaparral Sig 300 Gauges

I have a 1999 Chaparral Signature 300 that came with the Medallion digital/analog gauges that use a stepper motor. Each engine (Volvo 5.0GIPWTR, Serials 4110177853 & 855) has a Medallion MDC 1600 computer that converts the analog signals from the EEC to digital and then sends them up a two or three wire bus to the gauges. None of the gauges work and I have replaced one of the computers which did not help. The guages are no longer available. What I would like to do is retrofit with analog gauges. The information I seek is the connector type and pinouts of the analog signals at the EEC. I assume I will have to build a wiring harness for each engine. I have yet to find a dealer willing to help and both Volvo and Medallion have nothing to offer. Any help would be greatly appreciated!!

Re: Volvo 5.0GIPWTR Chaparral Sig 300 Gauges

I have no idea how the Medallion setup is hooked into your system, but standard analog gauges do not have anything to do with the engine ECM. there is a temp sender, an oil pressure sender for those, and the tach runs off the gray wire from the tach.

Here are the wiring diagrams for your engine and help as they would normally be installed without the digital gauges you now have.
http://www.4shared.com/document/_RfW-MIO/Wiring_WT_50Gi.html

Re: Volvo 5.0GIPWTR Chaparral Sig 300 Gauges

Thanks Don! I figured the output from the sending units and tach would have to go through the ECM for the fuel injection, which the schematic you provided confirms. My guess is, on page two, where the harness would normally go to the gauges, this has been re-routed to the Medallion computer to turn it into a digital signal. Chaparral only did this for one year, I think I know why! Swing and a miss.

This schematic is what I have been searching for for months. Thank You Very Much!!

Re: Volvo 5.0GIPWTR Chaparral Sig 300 Gauges

Don,

I now see that there are two sets of senders for temp and oil pressure, one each for the ECM and one each for the gauges. My mistake. Thanks again!