Altenator gauge spikes

0351mike · #1 (**permalink**) 10-10-2009, 03:16 PM

Hi all
Still struggling with the electrical system on my 70 wagon. When I turn the truck on- the altenator gauge reads 30 and then starts erratic spikes from 0 to 30??? What is going on here? All my gauges work besides the fuel gauge- I am getting power to the gauge- but when I put the test light on it it blinks about the same speed as a turn signal??? Can anyone point me in the right direction?

McLeod · #2 (**permalink**) 10-11-2009, 12:10 AM

Are you refering to an amperage meter or a voltage meter?

gfw1985 · #3 (**permalink**) 10-11-2009, 07:33 AM

Not quite sure about your "spike", but with the old style regulator it is normal for the amp gauge to jump at idle, headlights pulse. Switching to the later model electronic reg will cure that. Say one from a 78 Fairmont.

Boba Fett · #4 (**permalink**) 10-13-2009, 12:12 AM

On the fuel gage... start by checking the sender. To to this remove the electrical line running to the sender and ground it to the frame. It the fuel gage reads full.... you know the sender is no longer operating. Let me know if this works.

On the factory ammeter...its really a garbage gage. First...start by checking the alternator with a voltmeter/multimeter. Put one of the leads on the battery neg terminal.... then the other on the stud on the back of the alternator with the truck running... see what the gage reads.... usually between 12.x and 14.x... is it stable or surging up an down? If it is surging I agree with GFW.... first thing to replace is the regulator especially if you are still running and old stocker....... Also does your rig have performance pulleys on it? They can also be the culprit too....... if the voltmeter is stable and over 14..... .the forget the dash gage..... those things barely worked... from the factory!

0351mike · #5 (**permalink**) 10-13-2009, 07:59 AM

I will check the alterator out and let you know. I tried the sender on both gauges- no power to the sender- getting power into the gauge- did not check on the way out- I going to have to remove the whole cluster today to check it. Also could the culprit be the duel tank switch? This truck is a 70, but has the later electronic setup on it- looks the same as my 79 F150

Boba Fett · #6 (**permalink**) 10-13-2009, 11:10 PM

Definately could..... inside the dual tank switch are two contacts so that the guage in the cluster can flip between senders readings..... the contacts wear out over time.... you can probably check this with a test light... if you have power coming, but not going out then the dual tank switch probably needs replace.

0351mike · #7 (**permalink**) 10-14-2009, 07:23 AM

Well- tested the output at the altenator- and seems things are normal so I am going to disregard the gauge. I also have a new voltage reg, which I will throw in the truck in case I need it. I am trying to put this thing on the road, but seem to hit one thing after another. I had an idea about the switch. If I take the wires off the tank switch and jumper one of the wires from one sender together at this point (like I only had a single tank) I should get a reading or at least power back to the sender right?

Boba Fett · #8 (**permalink**) 10-14-2009, 09:02 PM

Yes. That should work..... Remember that if your dash guage still doesnt work try grounding the wire at the sender to the frame and see if the dash guage reads full. You could always have a back dual tank switch and bad sender...... You can also ground the hot wire on the dual tank switch as well and see if that causes you dash guage to read full.....

0351mike · #9 (**permalink**) 10-15-2009, 09:50 AM

Thanks for the help- I will let you know what I find out

0351mike · #10 (**permalink**) 10-16-2009, 06:20 PM

My guage still will not work. I have 1-2 amps coming out of the gauge. 1-2 amps (kinda blinking) at the sender. Grounded the sender- no movement. Does this point to a bad guage?

NumberDummy · #11 (**permalink**) 10-17-2009, 07:50 AM

Quote:

Originally Posted by gfw1985

Not quite sure about your "spike", but with the old style regulator it is normal for the amp gauge to jump at idle, headlights pulse.

Switching to the later model electronic reg will cure that. Say one from a 78 Fairmont.

What 1978 Fairmont came with an electronic alternator regulator as original?

None.

In 1982, Ford replaced all the previous alternator regulators used on 1963/64 Thunderbirds, 1965/81 passenger cars, trucks, Bronco's and Econolines with an electronic regulator.

E2PZ10316A .. Alternator Regulator-Electronic (Motorcraft GR540A).

E2PZ10316A replaced C3SZ10316A, C3SZ10316B, D4TZ10316A and etc.

The existing wiring harness is the same, with or w/o this electronic regulator.

When Ford did this, it p!ssed some ppl off...that wanted original style equipment on their vehicles (ppl with 1965/69 Shelby's, for example).

The electronic regulator's cover is flat, made out of aluminum and has MOTORCRAFT & ELECTRONIC embossed on it.

The simple solution is...just remove the original (painted either black or blue) regulator cover and install it on the electronic regulator. Then...no one will know the difference.
----------------------------------------------------------------------------------------------------------------------------------------------------------------------
ALL 1966/77 Bronco's used the same ammeter gauge.

C5TZ10850B .. Instrument Cluster Ammeter Gauge / Obsolete

Fits: 1966/77 Bronco.

Fits: 1965/66 F100/1100 / 1965/69 N/NT/T500/1000 / 1967/69 F800/1000 ALL with the round speedometer.

ED BENNETT FORD PARTS in Lebanon PA has ONE = 717-272-8762.

ANTIQUE AUTO SUPPLY in Arlington TX has ONE = 817-275-2381.

DON SANDERSON FORD in Glendale AZ has TWO = 623-842-8762.

No other Ford Dealer or obsolete parts vendor has any.

0351mike · #12 (**permalink**) 10-17-2009, 10:36 AM

So if I am getting power to the gauge- power out of the gauge, 2 volt at the sender, but not movement on the guage- and when I ground the gauge- no movement- what is this telling me- bad gauge, bad sender?

Boba Fett · #13 (**permalink**) 10-17-2009, 12:23 PM

Just to make sure.... you pulled the wire off the sender and grounded it to the frame on a good ground (an area free of grease etc)
You have a hot lead into the gauge.... and coming out..... and then you ground the lead and the gauge doesnt move? Reason I only ask so you don't buy parts you dont really need..... it seems like you have a bad gauge.... the senders could also be bad also, but you will have to fix the gauge first. I would do one last run through on the fuse panel with a test light... the clip grounded the point running through each side of the old bus fuses.... if the point lights the light on either side of the fuse the fuse is good...... if everything checks out.... your gauge needs replace....

0351mike · #14 (**permalink**) 10-17-2009, 03:56 PM

Yep- 2 volts to the gauge- I unplugged the tank switch and jumpered the correct wires together to bypass the switch- 2 volts there and then tested both senders by pulling the plug and testing- 2 volts there. To gound I pulled the plug- used the hot side of the plug and ran a jumper from there to the frame- no movement on either tank- I am going to go out and give it one more try- If the gauge is bad where can I find one-I am sure it has been obsoleted, but Ford probally used the same gauge on all their trucks in the 60s?

NumberDummy · #15 (**permalink**) 10-17-2009, 04:43 PM

Quote:

Originally Posted by NumberDummy

ALL 1966/77 Bronco's used the same ammeter gauge.

C5TZ10850B .. Instrument Cluster Ammeter Gauge / Obsolete

Fits: 1966/77 Bronco.

Fits: 1965/66 F100/1100 / 1965/69 N/NT/T500/1000 / 1967/69 F800/1000 ALL with the round speedometer.

ED BENNETT FORD PARTS in Lebanon PA has ONE = 717-272-8762.

ANTIQUE AUTO SUPPLY in Arlington TX has ONE = 817-275-2381.

DON SANDERSON FORD in Glendale AZ has TWO = 623-842-8762.

No other Ford Dealer or obsolete parts vendor has any.

Quote:

Originally Posted by 0351mike

If the gauge is bad, where can I find one?

See above. This info was originally typed in post #11.