Tonight I started my latest project: Swapping my idiot light cluster with a gauge cluster. Two hours later I had the cluster out. It was a b**ch to remove! I had to remove the steering column bolts to provide clearance to get the trim bezel out. Even though I protected my column with masking tape, I still managed to get two good sized scratches. Tomorrow I hunt for a close match to "medium green"..
Tomorrow I'll also start rewiring the cluster harness plug as per Mark's diagrams (thanks again Mark) I'll take some photos. Hopefully assembly is easier. Now that everything is out I have (what I hope is) a better plan to put it all back together.

 Todd

Sounds like a job and then some. Good luck and have fun.

More setbacks today. I got the main cluster harness connectors switched around to match the U.S cluster. I plugged it in and discovered several issues:
The fuel gauge reads 1/4 tank when in fact it is half full (I don't need it going any lower than it already is!)

The oil pressure gauge only reads about 12lbs cold

The temp gauge is pegged when the key is turned on

I swapped in gauge sending units for oil and temp but suspect they may not be correct. Mine are early Camaro units.

 I did an Ohm check of my old gauge and the new one. The old one read 44.0 Ohms and the new one is 67.8. If it were the other way (the new one was less) I could ad a 20 Ohm resister and be pretty close to the old gauge specs but I think I'm screwed with it this way. I'm trying to determine if the American Pontiacs used a different sending unit for the rally cluster fuel gauge. It is physically smaller in size. The fuel gauge may require a different sending unit which bites since mine is new.

The oil pressure gauge reads 69.1 Ohms and the temp gauge is 51.5 Ohms. Any idea how I determine what type of sending units I need?

Looks like the car will be down for a while until I get this sorted out.

Todd, have a read of my post "Good eBay Score", my cluster is going a bit better I think.

I did. Nice to see yours is "plug and play" whereas mine is "plug and scream"! Does anyone on here have a U.S Pontiac parts book from 1969? I need the pn's for the fuel sending unit (with rally cluster) as well as oil and temp sending units. Todd

Might you not be ok getting 69 Impala sending units?

That's what's in the car right now. It works great with the factory gauge, but reads 1/4 tank shy with the Bonneville gauge. I played around with it a couple of hours this morning (my day off) . I can spoof the new gauge by adding some resistance to the sender wire. I used a variable resistor and dialed it in until it read the same as the old gauge. I then read the Ohms reading on the variable resister and it was about 50 ohm. My only question is if I add a 50 ohm resister, would the gauge be accurate at all levels? hmmmm. I still cant figure out why my oil pressure sender isn't working properly. I can sweep it and the temp gauge using my variable resistor (NEVER toss out volume controls from old car radios-they are great as test units!) so I know my gauges are ok.

Everything seems to be working now. I swapped the resistor from my old gas gauge to the new one. I also modified it so that the printed circuit made contact with the resistor and it now seems to be working (it's reading half like the old one). The temp gauge and oil pressure gauge seem to work now too. It one of those things that you try something and it works and you really don't understand why! Todd

 Glad to hear it's finally gone your way!

I'm still holding my breath until it's all back together and STILL working. I'm not looking forward to putting that bezel back in and bolting everything back up. I still have this to install:

For future reference:

Today, 09:14 AM

77 Canamman Chief Ponti-yacker   Join Date: Aug 2006 Location: NY Posts: 705

According to partsamerica.com, the oil sending unit fits Chevrolet trucks from the mid-70's and Olds/Pontiac cars... http://www.partsamerica.com/ProductD...pe=417&PTSet=A The temperature gauge sending unit fits just about ALL GM cars for many years.. http://www.partsamerica.com/ProductD...pe=425&PTSet=A __________________ 1972 LeMans Sport conv., 400, M22, nice survivor 1976 LeMans Freeway Enforcer, 462, TH400 1977 Can Am, W72 400, TH400, black interior, nice survivor 2007 G6 GT, 3.5 auto

-- Edited by 73SC at 09:50, 2008-07-15

you are so smart    you should get a job in the country, as a consulant

Well, the cluster is in. My tach conversion is in as well. Everything is working however I am still a bit concerened about the oil pressure readings. Once the engine is hot, it reads just about nothing so either my sender is wrong or my engine is reeaallly tired! The temp guage is telling me the car runs a bit hot-just over 200 degrees. My clock-to-tach conversion looks ok-about a 6 out of 10.
Here's a quick photo:



It 30 bucks worth of gas in it. The gauge seems acurate-it moved 1/4 tank!

My cluster had 10 miles on the odometer. As you can see I put 7 test miles on it tonight.
One small problem is I now have an annoying metallic type rattle under the dash that I need to nail down...

 Todd

Throw in some heavier weight oil and see how it affects oil pressure. I had a Monza V8 years ago and the factory oil pressure was always low like yours, almost nothing at idle. I was so worried I changed the gauge to a mechanical and it was still low, so I put in 20w50 or something like that and presto it came up. I had that car for 5 years and gave it to my BIL who drove it for two more before breaking it in half but the engine was still going. You've got a 40 year old motor so it might be tired but probably nothing to worry about. Cluster looks nice by the way.

-- Edited by 73SC at 22:31, 2008-07-21

dash looks geat todd!
your 350 should have an oil passage plug right above the timing cover. thread a mechanical oil guage in there and see what you actual have (or don't) for pressure.

use a Ford sending unit   that used to work, to keep the red oil light off..  lol