1969 Mustang Bad Cv Regulator??

[YadiStang]

Last week I pulled my dash cluster, replaced the circuit board, cv regulator and swapped bulbs for LEDs (kit from NPD). I cleaned my gauges up while I was in there. It went pretty well but had some issues with my turn signal indicator bulb not seating well. Once I resolved that from underneath everything worked fine until this morning.... I start up the car and my gauges (fuel, temp, oil pres) all are erratic. Fuel reads full when I know its low. Temp reads high. Oil pressure is pegged. What gives?

Does anyone have bad experiences with CV regulators being faulty when new?

 

[tos]

I've heard of some Chinese made ones being erratic and I know I had an issue with a new voltage regulator being bad (Chinese made). First check your grounds, especially the ground from the gauge cluster. Next get a volt meter and check the voltage coming out of the CV itself. Should be around 5v give or take a half volt. I built my own adjustable CV from a diagram I found online and it works very well. If you should have to go that route I'll try to find the diagram.

 

[YadiStang]

I've heard of some Chinese made ones being erratic and I know I had an issue with a new voltage regulator being bad (Chinese made). First check your grounds, especially the ground from the gauge cluster. Next get a volt meter and check the voltage coming out of the CV itself. Should be around 5v give or take a half volt. I built my own adjustable CV from a diagram I found online and it works very well. If you should have to go that route I'll try to find the diagram.

I'm not really sure where to begin to check the grounds. It is a new printed circuit board (plastic) and the bulbs/gauges all mount through it. All my bulbs and indicators work fine which makes me think that the circuit board itself is connected to ground.

Another thought I had was that something must be shorting to ground because how else would the gauges, which are attached to senders, read max? The fuel, temp and oil gauges are pegging to the right. Maybe after my drive in the car a loose gauge post slipped in its mount and is shorting that particular circuit?

I wish I knew of a proper way to bench test the cluster or CVR. I have a voltmeter but I don't know what use for a power source. Can I simply use the car's battery or would that voltage be regulated somewhere before it got to the dash?

 

[tos]

The CVR receives 12 volts so yes you can use the battery but one of those wires hooked to it will be powered so verify it first. Then pull the ground wire off the other terminal of the cvr and see what voltage is coming out (should be 12v in and 5v out)

The reason I said check ground - Not because I necessarily believe that is the problem but rather with every electrical issue the first thing to do is check power and grounds are good. Many issues are caused by grounding problems (poor or non existing grounds). Gauges can do funny things that don't make sense when grounded poorly especially when there is a regulator involved. I'm not real familiar with the 69 but there should be a ground from your harness to the framework under your dash. If you can't find an obvious ground You could also pull the wire from the ground side of the CVR and do a continuity check from it to the a good ground to verify it is getting a good ground.

 

[YadiStang]

Thanks for the excellent advice. I will give it another go and report back with my findings once I receive additional parts (replacing heater core while I have it torn apart).

 

[YadiStang]

Actually.. I have another question: Does the CVR pulse? So if I check it with an analog meter, will I see the swing/pulse?

and....if you have that diagram or link for a variable DIY regulator, that would be appreciated!

 

[tos]

http://www.dimensionengineering.com/products/de-swadj

This is a link to the adjustable regulator. I will look for the diagram but basically I soldered connectors on the pins (blade type on voltage in and voltage out pins matching the blades on your CVR) Then on the center one (GROUND) I soldered a round terminal to mount it to my gauge pod just like the original bolted on (at least my 66 is this way). I put power to it on a battery first and adjusted the out voltge before installing then checked it again after installing.

 

[YadiStang]

hmm... I thought of something else.... Does the CVR only affect the gauges and the lights are are on their own harness circuit? This would make sense and also point me back to the CVR ($33 from CJ Pony...I'm sure I bought the cheapest one listed).

 

[tos]

Yes the lights are on there own although I don't know if your using led lights will need there own regulator. Generally leds use a lot less voltage so straight 12v might be too much? Not sure.

The CVR operates things that change in operation, things with variable readings like temp gauge changes as eng temp changes, fuel gauge changes as fuel level changes etc...

 

[YadiStang]

I did do a LED light swap. These came in a kit from NPD and were supposedly a straight-up replacement. They are working fine except the rheostat has very little effect despite the advertisement. I guess if they needed their own regulator I would know by now....but who knows. Taking a '69 cluster is messy - requires dash pad removal. Of course everything plastic wants to disintegrate. I needed brighter gauge lighting and needed to replace the old light difussers (practically opaque).

 

[YadiStang]

And here is an update... I took a test drive tonight since I haven't really experienced my new halogen headlights or the dash lights. My gauge issues have mysteriously disappeared. The weather got extremely hot/humid today, especially in the garage. I can see grounding issues being exposed during changes in weather but what about the CV regulator? When defective, are these known to be affected by weather?.