I have been behind in updating this thread. After taking the pic of the resistor I put it back in the circuit. It dinged for a couple days, but then started providing a reading (broken wire). I have been searching bone yards around here but as expected I have not found any donner cars. I expect to have to fabricate something form other resistors - too bad Radio Shack is gone.
Thanks to all for the info and the schematic (Schematics really help - see below). I now have a good target for the amount of resistance and other options such as changing the sender out to the autometer. (autometer site has some good info on senders) First I will be looking to get a good resistor in place.
Sidebar warning on the value of a schematic - Several years ago (1999?) wife's 91 ford probe had the oil light come on - no one could figure it out - a guy on my GN forum sent me a schematic - found the oil warning light bulb was in circuit for the alternator trigger/excite voltage - replaced the alternator to correct the oil light - would never have figured that one out without the schematic....
My wife's 85 Cougar (owned since new) has had a problem for years with the oil gauge reading low at times. I believe the problems is with the in line block resistor installed by the dealer when she purchased the car. Over the years the wire going into and out of the resistor block have basically broken. I would move them around and tape them to the block to maintain continuity. But, now it looks like I need to find a replacement for the resistor block. I've searched the forum and other sites only to find a reference to a 20 ohm value, but I think I recall it reading 25 ohms years ago.
Does anyone know of a source for this resistor block or the correct value so that I could build a block or find a suitable replacement (thinking of a ballast resistor or worse case a potentiometer)
