Guages question

[66StangFastback]

Hi guys. I searched for an answer to my question but really only turned up stuff on the newer mustang boards.

Question:
We get continuous voltage into the instrument panel voltage regulator and pulsing(intermittent) voltage out to the guages. Is this normal? Our guages aren't working. We do have voltage to the guages. Could it be that our instrument panel voltage regulator is bad, or maybe not grounded or anything? Any help or tips on getting these to work would be greatly appreciated!

We started up the engine today and it sounds incredible with straight headers. Now we just need to get these guages working and we're almost done.

Thanks in advance,
66

 

[smitzer]

I hope this answers your question. I could be wrong but I thought that you got a constant 5volts out of the regulator.

Someone correct me if I am wrong. I don't have my service manual with me.

smitzer

 

[shotsy]

Does this regulator have anything to do with the light being so dim in the dash. I just put my gauge cluster in my Coupe and the lights are so dim I can barely see them. Can I upgrade to the 4 led per bulb lamps that they sell at autozone, has anyone done this and what were the results? Also my voltage meter is right in the middle with the car off and when it's running, how can I tell if its working?

 

[66StangFastback]

Our dash lights were real dim until we replaced the light switch. Now our dash lights are bright, but our guages don't work.

 

[JB66]

The VR puts out an average of 5 v. It 'pulses' the 12-14v input to acheive the 5 v cheaply. When you ground the other terminal of the gauge, does it go up? An easy way to test gauge function is using 3 AA or C batteries hooked to each terminal. If it moves, it's working. Look somewhere else for the solution.

 

[19stang66]

the stock voltage gauges never really worked to begin with. Mine does the same thing and a fellow stangneter told me that there was a test done on how bad the voltage gauges actually were or something like that. I had to buy a new IVR and now only my fuel gauge works right, the temp and oil pressure needles move to the cold/low line and stay there. So I'm also having troubles with my gauges. My dash lights are awesome though, i love the classic green look on $20 white overlays from ebay!

 

[66StangFastback]

We've got the opposite problem. Out voltage and temp guages work, but not our oil or fuel guage. We've determined that the fuel guage works, because when we ground the guage itself it goes straight to full. but we don't have a full tank. We're thinking our fuel guage problem might be a bad sending unit? As for the oil guage, we don't know.

 

[randysusanne]

I am also having fuel quanity guage problems. I have the original sending unit which seems to be OK. Reads 79 ohms now which is what it is supossed to read. I have replaced my original guage w/Stewart Warner fuel guage. My question is, I believe the SW guage is expecting 12 volts and the sending unit is expecting 5 volts. Read an article that stated running 12 volts thru the original sender would fry it, but does the original stang (64.5) sending really expect 5 volts, or does 12 volts go to it and then drop down to 5 volts at the guage after going thru the regluator? I guess I'm asking if it would be OK to feed 12 volts to the original fuel sending unit. Thanks. Randy

 

[66StangFastback]

It's a 12V constant into the regulator, and a pulsing 12V coming out, the pusling averages to about 5 V constant into the guages.

 

[randysusanne]

If I bypass the regulator, will the sender be able to handle the 12 volts?

 

[JB66]

For a while, however, it will be totally useless since it will be off by about 240%.

 

[randysusanne]

Has anyone installed an after market fuel level/sender combo for a 65? I have looked at Stewart Warner and Autometer with no sucess yet. The problem seems to be the twist lock sender that the 65 tank uses. Any help would be greatly appreciated. Thanks, Randy.

 

[Tx3nC]

If I bypass the regulator, will the sender be able to handle the 12 volts?

The sender can handle it but the guages will smoke. The IVR is a mechanical, make-break style regulator. Things to check would be clean connections at the guages, good grounds, clean wiring. Problems with fuel guages can be caused by the gas tank not being well grounded to the car. Also, check the engine block to body ground strap. My mustang had several weird problems untill I fixed that block to frame connection.

 

[Edbert]

Has anyone installed an after market fuel level/sender combo for a 65? I have looked at Stewart Warner and Autometer with no sucess yet. The problem seems to be the twist lock sender that the 65 tank uses. Any help would be greatly appreciated. Thanks, Randy.

To my knowlege nobody makes a direct replacement for the factory tank that is different from the factory sender. There are many gauges made to use the factory senders though, they will bypass the factory harness entirely.

Alternatively, you could always get a fuel cell too, then you could use an aftermarket sender and get the added safety of the cell itself.

 

[Tim65GT]

Originally posted by randysussane

Has anyone installed an after market fuel level/sender combo for a 65?

Yes, my VDO gauge package came with it's own sender. It included small brackets that you can use to modify the existing sender and bolt on the new one.

I've had mine in there 4 years now, and works good.