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Bad gauge cluster voltage regulator? Easy $2 fix.

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Sorry, didn't check back enough posts. If not compatible maybe the components can be jumbled around to tune it to the correct regulated voltage???

The voltage regulator IC used for that can be found in a variety of output voltages so it is pretty easy to change. 5v is used for the gauges on a 1965-66 Mustang instrument cluster. Linear voltage regulator L7805CV would work. For the early Mustangs I'd probably modify the simple circuit here to filter the input slightly using at a minimum a bridge rectifier and a couple of capacitors on the input. The Mustang aftermarket is extremely well supported and you can buy these all over the place although usually in the ~$40 range.

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aintnobiscuit did it work ok on your 521? any pictures?


No, unfortunately it didn't work. The gauges only read from about 25% -> 50% instead of from 0 -> 100% full but this truck has weird wiring problems I haven't had time to sort out. I moved to hawaii and didn't bring any cars... just came back so here I am. Can't wait to start working on the truck again.

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Datzenmike please remove if you think this should go to the classifieds. This is not a for sale post just a feeler post.


First I'm not taking orders, I just want to know if there is interest enough in these to justify me ordering parts and building them for sale.


I've built and sold the voltage regulators in the past, there is a picture earlier in the thread of my old one I built.


I'm thinking of building these again and doing some minor improvements to the design also. Mostly add a reverse voltage protection and a little bit of filtering (e.g., a diode and capacitor on the input). This would up the cost of materials (2-3 times) and the time to build each one. The improvement would be the increased ability to survive reverse voltage if hooked up wrong. Downside is more expense on materials, longer time to assemble, and slightly bigger final size.


Most likely shipped cost would probably be at least $20 due to increase in time and materials.


Last time it was a bit of a pain in the ass all things considered, and I only made a couple dollars per and had to drive to the post-office each time.


Shipping was the most expensive part and going to the post-office each time was not fun. I can't mail from my house, every time I tried they would just disappear into the mail system and I would have to send out a replacement, only for them to show up months later. Most of the regulators sold to people not on the forum.


So is this something people would want? Is it worth me buying the parts and building these for sale?



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