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2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
Hey Ernie, i was able to coble together a variable resistor but it maxes out at 150 ohms. I was able to hit all but one reading and they were spot on with your marks so i have the gauge correct, i just need a compatible sendor. Any idea how i can match asendor that has a smaller diameter threaded plug the same as the 82?
The correct sendor sitting on the bench reads 500 ohms but the correct diameter Holley one i have is 1.5 k ohms. i think I'm kinda screwed
I would use the meter to adjust the float to get the correct resistance, then unplug the meter and connect it to the sendor lead. Bubba but it works, the flasher added enough ohms to get the higher readings
Last edited by Rescue Rogers; 05-27-2019 at 01:58 PM.
My god you done gone and done it with a fuel gauge.. lol..
The trick is that the reproduction and aftermarket senders don't have the correct scale to them as the original gauges.
So considering the temperature gauge is a non linear gauge (and so is the sender) you have to make a linear change that will transfer to the dash unit.
This is why I made the adjustable sender.... So any sender should be able to be dialed into the dash unit as long as it's a good non linear sender you should be able to dial it in... I hope this makes sense...
In 92 when GM sent the sender production to Mexico from Anderson IN, they screwed the pooch. They goofed on the thermister inside the sender, then the aftermarket companies followed suit by reverse engineering the senders to be 100 percent incorrect.
Then the reproduction senders hit the market with their so called "correct" manufacturing and guess what... I've cut every reproduction sender apart... and while there is one that states it's made just like the OEM with the oil inside.... when I cut it open there wasn't any oil inside.... Sad but true.
The funny thing is that the oil has no variable on the output of the sender, the oil keeps the thermister from corroding between the tension spring and the top cap... that's it's only function and the main reason the original unit's fail..... The oil leaks out, then the spring corrodes between the thermistor and the top plate... I've detailed this on my tech page many years ago (and when I had a bit more gumption to solve this issue than I have today)... It's a fun read but something I'll probably not do again. http://repairs.willcoxcorvette.com/1...ender-cleaned/
My gosh.. if someone was paying me to do this to an original gauge it'd cost them probably 300 dollars... do-able but the adjustable resistor is the way to go then you don't have to worry about it... I suspect your issue is the sender and if you'd like to send it to me I can test it... but this is something you can also do at home with a hot plate... (not boiling water)... With a hot plate you can crank up the temp, with boiling water we all know it stops at 212 so you can't get it any hotter because the water boils... with a hot plate you can take a temp rating and an ohms rating at the same time.
Also.. go to the tech site and search temperature... you'll see the reading chart I posted a while back on the different senders... that won't work.
Ernie
Last edited by Willcox Corvette; 05-27-2019 at 07:24 PM.
Ernie
Well another day, and of course another problem with my 73 Corvette. I finally decided to get rid of my very new looking, 12 year old tires last week. I used a tire store that does alignment work for the Corvette Service Shop I use. On the way back home, the hot sun started to heat up my car. The good news, is that the engine temp gauge stayed in the low range during the hour long drive back Home. The BAD news, is that the right channel on my original 73 Delco stereo radio stopped working. I had previously sprayed the volume / on-off, and speaker balance switch with Deoxit D5to clean off the 45 years of grime. The left channel continued to work fine. I turned off the radio and then powered it up after 5 minutes, and the right channel was back working again. I have read a number of posts on the Delco radios, and wonder if you would recommend changing out the Geranium Power Transistors on the convector? I hate to remove the radio, for the 5th time, and send it off to be repaired. The problem seems to occur after 25 minutes or so, with the right channel Going out. Your help is always appropriated. I am guessing you will be headed back East to relax and enjoy some lobster. Rest, and be careful when you are out jogging.
Eli
Since the passenger side is easy to get to I'd probably give that a try first. The Geranium Power Transistors are fairly cheap as long as you can find the right one. I believe the originals were stamped Delco, DS-501 7608 and 7609.
If that fails then yeah... pull the radio or get the replacement look-alike. I put the mack daddy one in my 62 and have had no issues. While they are expensive, the look is still the same they are easier to get in and out of the car if you need to get it out again. But I'll warn you, if you go with the newer style radio you'll need to upgrade the speakers in the front pad to get good sound.
Hey Ernie, i was able to coble together a variable resistor but it maxes out at 150 ohms. I was able to hit all but one reading and they were spot on with your marks so i have the gauge correct, i just need a compatible sendor. Any idea how i can match asendor that has a smaller diameter threaded plug the same as the 82?
The correct sendor sitting on the bench reads 500 ohms but the correct diameter Holley one i have is 1.5 k ohms. i think I'm kinda screwed
I would use the meter to adjust the float to get the correct resistance, then unplug the meter and connect it to the sendor lead. Bubba but it works, the flasher added enough ohms to get the higher readings
I make a sender that will fit a 3/8 npt hole... but I only make it up to the 1979 style It would probably work just fine but I don't remember what terminal connector the 82 style used. We custom turn these in house as they are ordered so they may take a few days to get one out.
Since the passenger side is easy to get to I'd probably give that a try first. The Geranium Power Transistors are fairly cheap as long as you can find the right one. I believe the originals were stamped Delco, DS-501 7608 and 7609.
If that fails then yeah... pull the radio or get the replacement look-alike. I put the mack daddy one in my 62 and have had no issues. While they are expensive, the look is still the same they are easier to get in and out of the car if you need to get it out again. But I'll warn you, if you go with the newer style radio you'll need to upgrade the speakers in the front pad to get good sound.
E
Ernie
Thanks for your help on changing out the power transistor. Do you have a schematic of the radio/convector that shows which transistor is for the right channel? I looked in the 73 Service Manual, there is a schematic that shows the left speaker coming out of the radio and not going through the convector? The right hand speaker comes out of the convector, but there are no wire color labels.
Ernie
Thanks for getting back to me fast, your diagram is different than the one in my Service Manual, this one is correct with the way the connectors are used.
Eli
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
Originally Posted by Willcox Corvette
I make a sender that will fit a 3/8 npt hole... but I only make it up to the 1979 style It would probably work just fine but I don't remember what terminal connector the 82 style used. We custom turn these in house as they are ordered so they may take a few days to get one out.
I still have the 68 end on my sender line, I made an adapter tor the 82 one I have so I can adapt it if I have too. I'll order it right now. Awesome!!!!!
Update, just ordered it. I left a note that its for me......
Okay... I'll check to see if we have one here already turned and if so get it out for you asap.... if not I'll send you a PM. But the question is what year is the car? I always forget.... I can just make one for that year of car instead. Okay.. just read above and saw it was a 68. Do you want one for the 68 style sender instead of the one your ordered which is a 72-79. I can make either one.
Ernie
Last edited by Willcox Corvette; 05-28-2019 at 03:42 PM.
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
Originally Posted by Willcox Corvette
Okay... I'll check to see if we have one here already turned and if so get it out for you asap.... if not I'll send you a PM. But the question is what year is the car? I always forget.... I can just make one for that year of car instead. Okay.. just read above and saw it was a 68. Do you want one for the 68 style sender instead of the one your ordered which is a 72-79. I can make either one.
Ernie
The 68 would work great, but which ever you have in stock.
So....several years ago, I removed my working wiper motor and put it in a box. Now that I'm ready to put it back on the car, I thought I would bench test it first.
Will your 73 to 82 procedure work on a 71 motor? All I'm getting is a "click". The battery shows 12.3 volts.
U79 stereo radio accessory for 1971 Corvette coupe
My 71 coupe came with the stereo am fm radio option ( U79 ) I would like to add a blue tooth stereo amplifier to improve the sound and add blue tooth connectivity to play music from my iPhone. Where can I get a wiring diagram of the radio and speaker layout?
So....several years ago, I removed my working wiper motor and put it in a box. Now that I'm ready to put it back on the car, I thought I would bench test it first.
Will your 73 to 82 procedure work on a 71 motor? All I'm getting is a "click". The battery shows 12.3 volts.
Thanks
Jim,
Go to the tech site, the info is there that will help you including videos and a very long tech article that includes simple schematics I've posted most links below so here is everything I have on your motor...
Bench test the motor first... then you'll know if it's good or not.
Here are the main articles and videos on the web site to help you.
My 71 coupe came with the stereo am fm radio option ( U79 ) I would like to add a blue tooth stereo amplifier to improve the sound and add blue tooth connectivity to play music from my iPhone. Where can I get a wiring diagram of the radio and speaker layout?
If you are going with an aftermarket radio they will come with a wiring diagram for installing the radio. If you add an amp it'll come with instructions as well. Are you going with the DIN style radio, if so you'll need to either need to cut the hole in your dash bezel or buy the one that is pre-cut and comes with a trim off plate. https://willcoxcorvette.com/corvette...uge-w-cd-68-97
05-27-2019, 01:40 PM
Sad but true.
It's a fun read but something I'll probably not do again. http://repairs.willcoxcorvette.com/1...ender-cleaned/
18243
