My workload was a little lite and the weather wasn't bad, so I decided to take a half day vacation to work on the Fiero. This week a new dual meter arrived to replace the one that quit working and I decided to test the one that was used on the 12 volt system that was not showing an amp reading. A headlight was wired to the shunt and the meter connections were made on the test bench and after a small puff of smoke, the meter went dead. It is discouraging because at least they both lit up when they were in the dash and the 120 pack ammeter was actually giving me a reading. I thought the low voltage and high voltage sides were isolated on the meters but when I hooked the ohm meter between the grounds, there is a dead short, so a 12 volt to 12 volt isolation dc converter will need to be added to the circuit. I found different dual volt/amp meters and ordered a couple of them. So the meter project is in "Hurry Up and Wait" status.
VOLT AMP METER
FUSE AND HOLDER FOR HEATER
Diodes are going to be needed to run power for the solid state relay that is being used for the heater so the element will not be energized unless the fan is running and 3 of them were ordered from Radio shack. Once again "Hurry Up and Wait."
NTE5812HC - RECTIFIER
A successful test was done on the solid state relay when the 12 volt control circuit was hooked up and an ohm reading taken across the output side. The indicating light lit up and the reading dropped from 100 mega ohms to around 3k ohms. I am figuring you need the high voltage hooked up for it to actually pass current so am not concerned about the reading.
After burning up the meter, I figured it is time to update the schematic so when they go back in the dash I won't hook up the wrong wires again. The red wire from the positive side of the traction pack also runs to the center of the console for the JLD404 and it was hooked to the low voltage positive wire coming off of the shunt. Since the dual meters do not seem to be isolated, it ended up smoking the power supply on the high voltage meter. Thank goodness these meters aren't real expensive!
DUAL METER SCHEMATIC
The wiring really needs to get finished so I can continue on with getting the interior back together.There is still the JLD404, Dell Venue 8, tachometer, and speedometer wiring to go before the center console and seats can go back into the car. Then I need to come up with a bulkhead to run the wires through the rear firewall. So much work, so little time!
Until next post,