willysmjeeps.com

Help!

How do you test a temp gauge? I bought a NOS sending unit and a NOS temp gauge. Nothing happens when the jeep warms up. I have a 1952 M38 24 volt. Thanks in advance.

was your gauge firmly grounded to the instrument cluster, and the cluster panel firmly grounded to the dash?

Have you used the M series 24 volt instrument troubleshooting guide in our download section yet?

http://www.willysmjeeps.com/v2/modules. ... tit&lid=46

This raises and interesting question for me. I bought a used NOS temp and oil pressure gauge from a military vehicle parts supplier here in MA. The new gauges looked exactly like the old ones and I simply swapped them out in the dash plate. Now though the temp gauge doesn't register anything and the oil pressure gauge seems to gradually fog up when the engine has been running for a few minutes.
I have replaced the thermostat too but not sure if everything is circulating right. The top coolant hose does gradually heat up but doesn't feel like there is pressure or coolant pumping through. I suppose that might also mean a bad water pump.
But the curious part is the oil gauge as my mechanic went through everything and I'm positve he confirmed that the water pump was working and the oil circulating. We had the oil hoses connected separate from the oil filter while I cleaned it and replaced the oil lines.
So, from reading some of the posts it seems like there are a few people with the same problem and part of it may be that the sending units differ from the gauges. Any other thoughts? It gets a little frustrating going back to work already done. I travel too much for work! Thanks!
-Josh

Thank you for the advice, I will try the trouble shooting guild, and be sure it is well grounded. I will let you know what happens. This web site is fantastic, and I love the passion you guys have for these old Jeeps!

If you use your parts list and confirm you have the correct part number gages and senders then use the troubleshooting guide there should be no problem sorting out any issues. As a second backup you can connect a direct reading oil pressure gage to the existing port at the engine's left rear corner and compare readings. You can do the same thing with the water temp by temporarily installing a civvy capillary type gage/sender and compare your readings.

So I finally got around to checking the numbers on the oil and temp gauges to match them up to my ORD 9. Here's what I have:
Oil Gauge: A/C 1509405
Temp Gauge: S.W. 505-S
I looked through the ORD 9 and while the oil gauge number is close, it's not the same as the other A/C stock numbers. From this information is someone able to advise me if I have the correct gauges installed in the instrument panel? They look like the one's I pulled out (and kept) and I will be checking to see if they are getting power. But are these the right one's? Thanks!
-Josh

Josh,
Your numbers appear to be much later than 1955. I didn't find them in any of the ORD 7, 8, or 9's. Perhaps they are modified late Packard rubber connector type gages set up for your metal Douglas connectors. The important issue is the range covered on the face be correct and the sender for the oil pressure matches the range of the oil pressure gage IE 60 vs 120.

Wes,
Thanks for that note. I'll double check the ranges to see. I got these from a military vehicle parts supplier here in MA. If I run into the situation where they are incorrect I believe that AJP and Midwest Military carries replacements. Is that correct?
Thanks.
-Josh

I have an SW 505 S type temp. gauge here with rubber Packard connectors/sockets in the back. The # on the face is: MS24543-2. In my M38A1, it was working normally, so it should be correct for your Jeep. Range is 120-240F wich is also right.

The original temp. gauge # should be 8376379/SW 505 N, but check this with Wes to make sure. I have seen SW 505 A in an earlier Jeep with the same range I think. Originality is very important, but I do not like not using half the scale on the oil press. gauge. Very few engines have oil pressure in the 100-120psi range and the Willys engine is not one of them. I replaced the gauge in my Jeep to 60psi (M170type) with the correct sending unit. Because the gauge does read 0-60 only instead of 0-120 it is easier to read and more accurate.

As long as the range is the same there is only the matter of adapting the rubber Packard connector gage to the metal Douglas connector harness.

If you are doing a factory resto and need the original gages then you will need to hunt for the correct ones.

I agree, the 60 PSI gage and sender are a better choice for a daily driver.

OK, I took a look at the gauge readings. The temp range is 120-240 and the oil gauge range is 0-60.
Thoughts? Thanks.

Based on the picture that "gorzel", Michael G, posted under Trico Motor Rebuild it looks like my Temp gauge is wrong but my Oil Pressure gauge is all right. Based on the ranges I posted a few days ago, does everyone agree? Which means I'll need to get the right gauges from somewhere...
Thanks.
-Josh

Sounds like you are on the right track.

Keep an eye on ebay, sometimes they show up there.