stock gauges and sending units ?

[blazer2007]

converting from idiot lights to gauges and I have 3 gauge panels I,ve collected and one of the clusters have fonts in stead of pictures.My question is are the sending units different on some years. thanks

[tucsonjwt]

I am not sure about the gauge/sending unit pairing, but the sending units can be 2 outlet or 3 outlet (if a vapor recovery or evaporative canister is in the truck.)

I used Spectra aftermarket sending units in my 83 dual tanks and they caused the gas gauge needle to bounce. My AC Delco units did not do that, but they cost about $150 each and the Spectra units were about $50 each.

[El Dorado Jim]

I think the sending units are the same, even though the gauges look a little different

[Dead Parrot]

If we are talking about the engine gauges, (temp, oil, etc), there are, IIRC, 3 different sender resistance curves in the OEM senders for temp. OEM senders are few and expensive. Many aftermarket senders don't match the OEM curves and give poor temp readings. I think the oil senders are the same thru the years except you have to match the full scale PSI on the gauge to the sender.

I think that dropping a volt meter into the slot where a amp gauge sat results in bad stuff like escaping smoke.

The resistance curve for the gas gauges have stayed consistent for many years.

You can re-pin the cluster connector to match your truck to the cluster you decide to go with. The connectors physically stayed the same but the positions in the connector changed often.

[hatzie]

There are at least three different Temp senders. Two of them have proper aftermarket curves on the replacement Delco and Aftermarket units.
@1980 & prior Nail Head senders are the only ones that are a mild problem.
If you are willing to get used to what is normal operation of the needle for your new sender the replacement is not a problem. The needle will just not rest where it used to and the numbers, if your gauge has em, will be incorrect. Just get an overlay with H & C and lines in between.
If you have one of the affected pre 1980 gauge panels and must have as-factory operation... Letric Limited and Wilcox Corvette sell replacement Nail Head senders that actually work quite well but they are Pricy...
You can install a 1981 & later temp gauge in the earlier panels and it will work with the later sender that matches the gauge.

Oil pressure and Fuel gauges are 0-90Ω units 0Ω=0 & 90Ω=F or High oil pressure. Get an oil pressure sender to match your gauge the C40-C60 trucks had 80PSI gauges. The idiot lamp cluster used a blue wire for the oil pressure switch. It'll plug right onto the oil pressure sender but it's a dead giveaway that it was not originally a gauge equipped truck...

There are instrument cluster plug pinout cheat sheets in the 73-87 electrical FAQ. You will likely have to add at least one power wire and maybe a ground to the cluster plug.

The Instrument Cluster Plug terminals are called "GM Printed Circuit Terminals". GM used these in a bunch of vehicles starting in the late 1960's through the early 1990's. The Delphi Packard printed circuit terminals are discontinued but can be purchased if you are willing to pay for a batch of 5,000. Reclaiming some from a wreck was the only option til recently... Classic Industries has apparently bought a minimum run because they now sell the 73-87 Pickup instrument cluster plug shell and terminals new.
http://www.classicindustries.com/pro.../bw900217.html

You can get project pak assorted colors of GXL or SXL jacketed wire in 25' lengths from the Wirebarn on evilbay or you can buy 250' spools from Del City or Waytek or ...

[blazer2007]

thanks for the reply's, some thinking to be done.First I better make sure the older font style gauges work,I know the others do but I like the font style. I did get some packard terminals from a old local electric rebuild shop and old rope type goo for the terminal block,maybe I should grab more and it was free.They had to send the dad [85 years old] out because the young guys never heard of a packard terminal