Engine temperature gauge has no power to sending unit.

[ArdWrknTrk]

Thanks Jim, I'll check the resistance in the wire.

Right.

So you can ground the R/W wire to the block and check from the instrument plug to any ground in the cab, and the wire should be close to 0 ohms.

You can plug it into the sender and it should read close to 73 ohms with a cold engine.

You can check the sender itself from where the wire attaches and again see ~73 ohms (cold)

If you get infinity (OL) with the first one there is a break in the wire.

If you get (OL) with the second and third one the sender is bad or someone used Teflon tape and the sender is not making a good connection to the intake manifold.

I don't include option three (cab isolated from ground) because apparently the oil pressure gauge seems to work.

[CDLong]

Thanks Jim, I'll check the resistance in the wire.

Right.

So you can ground the R/W wire to the block and check from the instrument plug to any ground in the cab, and the wire should be close to 0 ohms.

You can plug it into the sender and it should read close to 73 ohms with a cold engine.

You can check the sender itself from where the wire attaches and again see ~73 ohms (cold)

If you get infinity (OL) with the first one there is a break in the wire.

If you get (OL) with the second and third one the sender is bad or someone used Teflon tape and the sender is not making a good connection to the intake manifold.

I don't include option three (cab isolated from ground) because apparently the oil pressure gauge seems to work.

Weather here hasn't been cooperative. I finally checked the wire with it connected to the sender. Engine was cold, hasn't been operated since yesterday morning. You can plug it into the sender and it should read close to 73 ohms with a cold engine. I have 62 ohms

You can check the sender itself from where the wire attaches and again see ~73 ohms (cold)I have 65 ohms. I couldn't check the wire disconnected from the sender. No helper was available, and I couldn't get a good ground. I did get all the dash light bulbs tested. They're all good.

 

[ArdWrknTrk]

You can plug it into the sender and it should read close to 73 ohms with a cold engine.

You can check the sender itself from where the wire attaches and again see ~73 ohms (cold)

I have 62 ohms

You can check the sender itself from where the wire attaches and again see ~73 ohms (cold)I have 65 ohms

65 ohms isn't bad.

With that the needle should budge but not sweep up into [NORMAL]

The other way you could check the gauge is to backprobe the sender wire at the plug behind the cluster to ground (any metal frame of the dash) and with the key on the water temp should be pegged.

While the sender seems a little out of range I think you should confirm it's bad, and the gauge good, before condemning it.

If both ohm readings are the same (and the meter battery is good) then the wire shows 0 added resistance.

 

[CDLong]

You can plug it into the sender and it should read close to 73 ohms with a cold engine.

You can check the sender itself from where the wire attaches and again see ~73 ohms (cold)

I have 62 ohms

You can check the sender itself from where the wire attaches and again see ~73 ohms (cold)I have 65 ohms

65 ohms isn't bad.

With that the needle should budge but not sweep up into [NORMAL]

The other way you could check the gauge is to backprobe the sender wire at the plug behind the cluster to ground (any metal frame of the dash) and with the key on the water temp should be pegged.

While the sender seems a little out of range I think you should confirm it's bad, and the gauge good, before condemning it.

If both ohm readings are the same (and the meter battery is good) then the wire shows 0 added resistance.

Unfortunitely, dash is out of truck, waiting on new cable that shows what gear the auto trans is in. The meter seems to be correct. I checked 2 Ryobi batteries, 20V each. Truck battery is 12.4 V with engine not operating. sender is new. I installed it when I did the major tune up. I remember the gauge did not move with the old sending unit or the new sending unit.

[FuzzFace2]

Unfortunitely, dash is out of truck, waiting on new cable that shows what gear the auto trans is in. The meter seems to be correct. I checked 2 Ryobi batteries, 20V each. Truck battery is 12.4 V with engine not operating. sender is new. I installed it when I did the major tune up. I remember the gauge did not move with the old sending unit or the new sending unit.

Because the cluster is out is why I say now is the time to test from where the plug goes in all the way thru the cluster, IVR the gauge back out to the plug.

Then again because you know the fuel and oil gauges work if you put power to the IVR and check at the temp gauge in and then out all the way back to the plug you will know for sure that part of the cluster is good before you go putting back in.

Being it sounds like the new sender and wire back to the plug is good is even more reason to check the cluster.

Dave ----

[CDLong]

Unfortunitely, dash is out of truck, waiting on new cable that shows what gear the auto trans is in. The meter seems to be correct. I checked 2 Ryobi batteries, 20V each. Truck battery is 12.4 V with engine not operating. sender is new. I installed it when I did the major tune up. I remember the gauge did not move with the old sending unit or the new sending unit.

Because the cluster is out is why I say now is the time to test from where the plug goes in all the way thru the cluster, IVR the gauge back out to the plug.

Then again because you know the fuel and oil gauges work if you put power to the IVR and check at the temp gauge in and then out all the way back to the plug you will know for sure that part of the cluster is good before you go putting back in.

Being it sounds like the new sender and wire back to the plug is good is even more reason to check the cluster.

Dave ----

I assume I can use small alligator clips to connect to the plug, but how would I connect the wire to the ribbon?

[Gary Lewis]

Unfortunitely, dash is out of truck, waiting on new cable that shows what gear the auto trans is in. The meter seems to be correct. I checked 2 Ryobi batteries, 20V each. Truck battery is 12.4 V with engine not operating. sender is new. I installed it when I did the major tune up. I remember the gauge did not move with the old sending unit or the new sending unit.

Because the cluster is out is why I say now is the time to test from where the plug goes in all the way thru the cluster, IVR the gauge back out to the plug.

Then again because you know the fuel and oil gauges work if you put power to the IVR and check at the temp gauge in and then out all the way back to the plug you will know for sure that part of the cluster is good before you go putting back in.

Being it sounds like the new sender and wire back to the plug is good is even more reason to check the cluster.

Dave ----

I assume I can use small alligator clips to connect to the plug, but how would I connect the wire to the ribbon?

Yes, an alligator clip can easily connect to the sender. And if you are careful you should be able to use one on the ribbon. If I remember correctly the ribbon wraps around the connector and sticks out a bit, so you should be able to gently put a clip there. Gently. Or just use the probe from the meter to touch the trace.

[CDLong]

Yes, an alligator clip can easily connect to the sender. And if you are careful you should be able to use one on the ribbon. If I remember correctly the ribbon wraps around the connector and sticks out a bit, so you should be able to gently put a clip there. Gently. Or just use the probe from the meter to touch the trace.

I was thinkin' a male spade butt connector on the ribbon end of the jumper wire so it could lay on the ribbon. Harbor Freight has small plastic clamps but I don't know if there's enough room in the panel to use them.

[ArdWrknTrk]

I remember the gauge did not move with the old sending unit or the new sending unit.

Which leaves you with either the instrument itself or a bad flex.

It's pretty easy to see tears and corrosion on the mylar.

Our member Blue Truck Parts (where you probably got the indicator cable) has a refinished temp gauge on eBay for $40, though it might stick out on an old cluster.

There are other used 'known good' ones there for ~$30 delivered.

 

[CDLong]

I remember the gauge did not move with the old sending unit or the new sending unit.

Which leaves you with either the instrument itself or a bad flex.

It's pretty easy to see tears and corrosion on the mylar.

Our member Blue Truck Parts (where you probably got the indicator cable) has a refinished temp gauge on eBay for $40, though it might stick out on an old cluster.

There are other used 'known good' ones there for ~$30 delivered.

I have been considering a refurbished gauge. Thanks Jim.