Sunday, October 18, 2015

FABRICATING THE MOUNTING FOR THE VOLT/AMP METERS

Saturday my wife and I met my family in Coshocton to go on the Fall Foliage tour. We skipped the last two farms on the tour and went to the Roscoe Village Apple Butter Stirring Festival. That pretty much took up Saturday so no work was done on the Fiero.


ROSCOE APPLE BUTTER STIRRIN'

Sunday morning was chilly but started warming up around 9am, so it was time to start on reworking the instrument cluster to incorporate the Volt/Amp digital meters. Right off the bat, I could not find a socket or nut driver that fit the small screws holding the face plate on, so drove over to Ace Hardware in Baltimore, OH to pick up some tools. Before EVCCON I picked up a 1/4 inch drive metric socket set so after finding out the socket I needed was 7/32 picked up a 1/4 inch drive, inch socket set and some inch nut drivers. 

Templates were made for the face plate to mount the meters and the terminal spacing to plug into the existing contact clips that were removed from the instrument cluster that origanally came with the car. The hole locations were transferred to a piece of aluminum sheet metal and were drilled out, then a template was made for the meter and was cut out on the plate with a Dremel cutoff wheel. The plate edges were cleaned up and the meters were tested for fit.


METER MOUNTING PLATE

Then focus turned to making a contact plate so the original contact clips can be used to connect the meters. The holes from the template were transferred to a piece of plexiglas and were drilled out. After another trip to Ace Hardware, brass screws were located in the holes and screwed into place. The contact plate fit like a glove and should work out great.


OLD CLUSTER WITH CONTACTS REMOVED


NEW CLUSTER WITH CONTACTS


STUDS ON BACK OF TEMP AND FUEL GAUGES


CONTACT PLATE


CONTACT PLATE MOUNTED


FACE TEST FITTED

The dual Volt Amp meters are not isolated, so I have to use a 12 volt dc-dc converter to power one of them up to make sure the pack negative is not tied to the 12 volt negative. The leads on the dc-dc converter are very small and require soldering the wires onto them. This can be done but twice not I have had a solder joint fail and the wire come loose, causing the meter not to work, so found a connector that the dc-dc converter will plug into that has connections that you push the wire on to connect them. I believe this will be a much more reliable way to connect the wires to the DC-DC converter and will make the operation of the Volt/Amp meters much more reliable.


DC-DC CONVERTER CONNTCTOR

Next weekend the wiring will be started so I am digging up the instrument cluster schematics and diagrams to find the wires that will need to be spliced to be able to use the original connectors.

More next week,

Randy

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