So just as I thought I was out of the woods and the temp gauge needle was working correctly. i reared its ugly head again. Though I have not had a chance to climb under the dash yet,and take the green wire out of the ignition switch. The temp gauge was working fine smoothly climbing from the warm up to just under 1/2 and staying steady. I took the car down to the engine builder for it first oil change after the rebuild. started the car and the gauge worked fine. About half way down to the shop the temp needled starts hopping from cold to hot and all over the place, So I pulled over and popped the hood and moved the connector a bit on the temp gauge mushroon at the engine. And all was fine for the rest of the drive down to the shop. The connection seemed rather loose not real firm on the connection to the sensor. While down there I mentioned what had happened and we pulled the connector and there was sone corrosion. So he grabbed his trusty jeweler's file and cleaned the contact tab. I left and all was good for about 10 minutes and the needle started hopping around again. I stopped at a gas station to fill up and again moved the connector on the sensor and the needle dropped down to cool and never returned to the 180 ( just under 1/2 hash mark. I parked the car and went about life as usual. Tonight while there was still light since I don't have a garage to work in. I went out pulled the terminal on the sensore and removed the plastic cover and soaked the copper connector till it was clean and shinny again. Adjusted the tab by bending it upwards a touch from the terminal and pinched the termina a bit tighter. I re attached it to the sensor and it had a good snug fit. Started the car and watched for the temp needle to rise.I had a little fluctuation. started to climb and again started to hop araound but not like it did on the road. The oil gauge needle fluctuates a little bit also but not like the temp needle is doing. Could it be the connector or wire end at the connector? It is the original engine wire harness. Everything at the gauge is tight. The pins are tight to the circuit board. The connector at the gauge is wired right and the connectors are tight. The temp sensor is a BWD WT203 which is supossed to be the right sensor unit. Should I go with a different brand? Another thought is could there be interferance from the Oil Pressure sending unit wire since they are wrapped together in the harness tap? Once again i am racking my brain and reaching out for help. since there are only two weeks of shows left. I might just shut down for the Winter and send the gauge out to be checked and calibrated. It was only cleaned and lubricated. but never calibrated. It is an original gauge from a 72 442 that I bought from a friend. But any ways her is a picture of the wiring down at the Temp sensor and Oil pressure sending unit. And also a 1 minute video if the temp needle doing the happy dance !


Ironic the commercial that is on in the beginning of the gauge video !

 

Very strange indeed. I wouldn't mess with the wrapped wires. The way the gauge needle jumps suggests a problem with the sender or the gauge, and since it happens erratically / randomly, I'd lean toward changing the sender, even though it's new. Here is a thread you may find helpful to test the correct resistance / ohms of the sender: https://classicoldsmobile.com/forums...2-442-a-13029/ The thread mentions a Borg Warner WT203 sender is correct for gauges.

 

Thanks Tom thought you'd get a kick out of the happy dance needle video ! Do you know if the connector for the temp gauge wire is still available, and where I could get one? I will reach out to Scott Wynn and also Al Sutton.

 

Before doing anything else, carefully inspect the wiring harness. At this point, I wouldn’t unwrap anything, just look for areas of the harness that may have been pinched or crushed. If you find anything, unwrap the harness for a more detailed inspection.

If that checks out, unhook the sender. Ground the wire, the gauge should go full hot. Have a helper sit in the drivers seat and watch the gauge. While your helper is watching the gauge, move the harness around. Get kinda rough with it, the idea is to duplicate a break in the wire, or grounding of the wire. Move things around at the firewall connection as well.

You will need to have the ignition on for this test. I don’t know if you have ignition points, be aware that it’s pretty easy to burn up the points with the key on, engine off. Either have the engine running, or unhook the positive wire to the coil. Make sure you insulate the terminal while it’s unhooked.


If the gauge doesn’t flicker with the wire grounded, either you have a bad sending unit, or the bad connection is under the dash.

 

I would suggest your sender is wonky. If the gauge holds steady most of the time it seems logical there's something going wrong with the element in the coolant sensor.

 

The original temp sender (both idiot light and gauge senders) had vertical blade-type terminal on the top. Your replacement gauge sender, like many others is a button-top terminal that has a side slide type connector (open side). You could but don't need to change the plastic connector since that has nothing to do with the intermittent temp reading on the gauge. You could change the terminal on the lead wire that connects to the sender top, if that is what you are thinking. But I and others are suggesting that you try other diagnostics, including testing and/or replacing the sender, and/or checking the temp sender wire.

I have to say, I'm still confused about the "black" wire discussed in earlier posts that you disconnected on the gauge connector on the back of the gauge pod that initially seemed to be the solution, but then wasn't. Are you absolutely sure the pin on the circuit board for the temp sender on the back of the gauge pod is making good contact?

 

Thanks to both of you guys for the input ! I'm am going to probably start with connector. I did notice that the terminal looks a bit worn at the connector and the wire was at one time bent 90 degrees to the end of the back of the connector. A quick question regarding the Packard 56 female connector. When I cleaned the one on the harness at this time it looks to be either brass or copper, I have located someone that has tin plated brass 56 terminals. Or is the standard 56 terminal that I have in my Packard terminal kit which looks like white metal, which I am assuming would be steel or zinc? be ok. I'm asking since the top of the sender unit is brass and I know some metals do not react well together. After I replace the connector and issues are still present I will switch the sender unit. and if no change I will work back towards the firewall and inside up to the gauge. Some of the connectors on the engine wire harness are showing thier age but not to a severe point of concern, except the alternator which is going to be repaired over the weekend or soon after. ! Need to find this connetor cover. Checking with the person that is supplying me with the 56 terminal and slotted cover.

 

Tom I did check the pin one the back of the gauge and the circuit board and it did not show any movement in the slightest for. But I did not dis assemble the gauge at this time to check the internal. I amd a bit squemish about taking the unit apart since I am not a technical person. I did do the speedo back in 2005 when I started the restoration and the car was in the body shop. But that was pretty straight forward. A friend of mine has a real good guy who has been restoring rallye gauges and all others for decades, I am trying to get the name from him. I remember the first name being Frank but don't recal the last name. I'm going to try and contact him and send him the video of the needle happy dance and see what his thoughts are and if he thinks it's the gauge or outside influances ! Thank you for being so patientand help me by guiding me through all this with your thoughts and suggestions. Regarding the phantom black wire, kinda stumped on that one too. Except one thought was since it was not the original but one I bought but OEM. Could the black wire possible be different gauge back to idiot light gauge with seatbelt warning light? Or would that have been in the speedo gauge.


Sorry for the bad quality picture. This was taken when digital cameras first came out ! LOL

 

Tony, I'm confused. These images are the alternator connector. I thought your post is about the temp gauge.

You can re-use the open-side slot connector if you are changing the terminal.

 

The seatbelt warning light is in the gas gauge / idiot light pod on '72s.

 

LOL ! No I added this because I also need to replace this connector cover and terminals. Was part of the conversation about me getting the Packard 56 Blade and slotted cover from the same person.

 

I think all the old original equipment 56 series terminals were brass plated. I’m betting they started plating them with tin as a cost savings. Either style would work just fine. If you can find a dealership with old inventory you might be able to get brass coated. Last few times I have ordered terminals they are tin plated.

No matter which style you use, a little dap of die-electric grease will prevent corrosion.

 

I checked my spare connectors bag and I do not have an extra alternator connector.

 

The connector on your alternator looks like a Packard DN (external alternator). Less than $2.00 at RockAuto

 

Is the oil sender connector remade? It's the blue wire in post #41. My wire is cracked in 2 locations in the first 6 inches and the black boot that connects to the sender is stiff and brittle. Choices are pretty slim while searching Google. The closest I found was an AC Delco with a gray wire, and I'm not sure that it's correct because the description doesn't say anything about it.

 

Thanks Allen.
I actually got one from a seller on Ebay that also had the Packard 56 in tin plated copper. He had a left over original Packard DN. The only difference was were the tab connect to the housing. My original is a little thinner at the base. As you can see.

 

Figured out what the black wire might have been, The idiot light gauge had a seatbelt warning light ! Talking to someone else about the conversion over from stock gauge to manual also said his had the same wire in the harness.

 

My 72 had a black wire in the harness as well. The seatbelt warning light makes sense.

Anyone know of a replacement for the oil sender connector? Mine is brittle and I’d like to replace it.

 

So here is a good news update !
As I was removing the Lower dash ductwork in order to get to my now NON working convertible top switch ! UGH ! I found a ground wire which I had previously installed. The screw the it was attached to along with the duct work was loose. I relocated the ground strap to a different location, removed the Female connector at the Temp sensor and replaced it with a new connector and cover. I also did the same with the alternator connection. Re attached the terminals with dilactic grease and started the car up.Temp gauge smoothly climbed as the engine warmed as did the oil pressure needle.Once the temp leveled out at appro 180 I took the car out for a rund around the block and both the temp and oil gauges stayed smooth and reading properly ! I will remove the Green wire from the ignition switch while I am under the dash replacing the top switch ! So no more needle happy dance and all is good. ( Fingers Crossed ) .

Thanks again to everyone for your guidance especially Tom !

 

I merged you latest post to the original thread so people would know the problems history. Glad you got it working correctly.

 

Glad you got this sorted out, Tony. (Did you replace the temp sensor as well that you inquired about in another thread?)

 

Hi Toms cutlass.
No I didn't need to, once I replaced the temp and alternator terminals and found the loose ground wire under the dash. Everything turn back to normal. But I do have 3 extra Delco temp sensor units now just in case ! LOL. I do still need to remove the green wire from the ignition switch. Which I will do while i'm replacing the convertible top switch now. Since you have helped me out with these issues. Perhaps you can also help me with the top switch issue. I put the top down for a show. when I went to put the top back up there was no responce. Not sound from the motor or movement. The swtch though it still had up / down movement, it seemed very stiff and some limited movement to what it was previously. Since the switch works without the accessories off, I assume that it is not a fused switch. I did not see any notation for top switch on the fuse block diagram. But do wonder if the top relay might have gone bad. If I replace the switch should I replace the relay at the same time. The car is done for the season and in a client's garage for the Winter so I have time to pull things apart.

 

You are correct, the top is not fused through the fuse box. The convertible top switch runs through a 30 or 40 amp circuit breaker on the engine side of the firewall located above the engine side of the fuse box.

Before throwing parts at it, I'd test for power at the switch. It's a single-pole, single throw switch.

 

Thanks Tom,
I will check the switch Saturday when my mechanic friend comes out. Luckily I have original working switch on the way. Got it with it's original wire harness for $65 with is better than any Jap crap repro price wise. I think relays are in different locations 72 vs 70. I know I don't have a relay on the driver's front wheel well like yours does. But I will check the relay that is near my Brake booster. I know the one at 1 o'clock is the Heat/AC Blower relay since we had to recently replace it. but there might be another relay below or beside the brake booster.

 

To be clear, I didn't mention anything in my post about a relay or its location. Your power top is connected to a circuit breaker (that is likely wired through the horn relay, which in turn is wired directly to the battery). The '72 CSM would show locations.