Re: 48-50 Bimetal Senders Retrofit Project

Posted by humanpotatohybrid On 2024/5/3 21:55:13

Thanks Howard. I'll read through those shortly.

I have a Chilton's (?) manual but idk if it goes back that far.

From the service letter and DP's data it's clear that the water temp gauge indicates backwards compared to the other two, but with the same range. At least for the gauge, this can be easily accomplished by physically reversing the assembly inside it during the manufacture process.

Therefore it may be assumed that the oil and gas gauges operate according to DP's data, just reversed. I.e. a high impedance at the sender gives a low gauge reading and vice versa.

It should be noted that all 3 gauges on the later cars followed this same pattern of high impedance = low reading. Actually I'm not certain on the oil pressure gauge, so maybe Howard can confirm that.

I think if there is a device that can trim both for an input threshold, and an output range, and can reverse the logic between input and output, it could be easily set up to make any sender work properly with any gauge. I'll have to see if I can come up with something. Of course, this would work not only for the 48-50, but the other obsolete types and also for all makes. Thr only assumption is that both scales are linear, so if I can make a decent "reverse exponential" device separate for 48-50 it may be best to do so.