Im in need of some help!

[AbelG 0]

Hello im new here i read some of the forums on here and i told my self you should register and try asking for some help. Well i have a good friend who needed some help finishing putting his car back together its a 1969 boss 429 . The gas and temp gauges are not working. When you ground the connectors going to the sendors the gauges dont sweep i did the 9 volt batt test that was good.One thing that i did find is i downloaded a couple of cluster wiring diagrams and on one i saw the wires going to the connector for the cluster didnt match one of the diagrams but did with another one i saw . Thank you for your time and i would appreciate some help.

 

[jmlay 80]

The connetor is pinned differently for a dash with a tach vs without tach. Verify what you have and the look at the diagrams and schematics.  Some great resources on this site for electrical. Visit the how to portion of the forum for wiring diagrams and schematics.: 

http://1969stang.com/forum/index.php?/forum/45-how-to039s/

[Mach1 Driver 560]

Hello there, you've come to the right place. As jmlay mentioned, there are several posts that would help. Go to "How to's" and look at "Fixing the Instrument Panel, "A Real Schematic", and "1969 Mustang Wire Diagram".

You've mentioned doing a 9v battery test. Actually it only takes 3v (two D batteries in series) to get the needles to sweep, but it probably did no harm. It sounds like the fault is between the gauges and the senders. So it could be the flex circuit on the back of the instrument panel, the connector to the flex, or the wires. The wire diagram shows both tach and non-tach car wiring- just find the correct page. Same for "Fixing the Instrument Panel- the non-tach version is first and the tach version follows. Let us know if we can help further.

A Schematic simplifies the circuit so you can see at a glance how it works. From your description you probably have an open circuit somewhere in the area of the red arrow (in a couple of places). 

[Midlife 814]

A common problem with 69/70 dash clusters is that the gauges (except ammeter) don't work.  The reason is that one of the various posts of the gauges is touching the metal housing, which basically shorts all of the gauges.  This often happens when one replaces the circuit card.  To solve, take the dash out and loosen the 2 bolts for one of the gauges and re-set the gauge in the housing and re-tighten the bolts.  If you have a multimeter, measure the resistance between any one of the posts and the metal housing of the dash cluster.  If you see 1 or 14 ohms, then one of the bolts is touching.  You will spend a fair amount of time re-setting the gauges until you get a reading of kilo- or mega-ohms: that is the reading you want.

You can't see the issue, as the view is obstructed by the circuit card and the cardboard insulation pad underneath the bolt nuts.

[Rsanter 152]

The printed circuit on the back of the gauges fails

take a look at it

[AbelG 0]

I would like to thank you guys for your responses ! After reading them i realized i should have given a little more info on this issue , this car has a tach i had to replace the circuit board cause it was torn a little in one of the corners also replaced the voltage regulator.I ohm checked the posts on the gauges to the metal housing and it seamed ok. The other problem is i have no power at the 4 amp fuse i think its #5 the smallest one. I also checked for power at the violet wire at the cluster connector key in on position nothing?

[Mach1 Driver 560]

I suggest you read 69-70 instrument gauge cluster 5.docx, in particular these pages: pg 3 gauge posts shorting to housing, pg 4 IVR, pg 6 gauges, pg 7 chassis ground, pg 18 chassis ground, pg 19 temp gauge, pg 20 fuel gauge, pg 21 oil light, pgs 22-23 "everything else".

The 4 amp fuse see page 2 of the schematic, power for the fuse comes from the light switch:

 

 

[Mach1 Driver 560]

AbelG  said: "I also checked for power at the violet wire at the cluster connector key in on position nothing?"

That is why the gauges don't work, there is no power to the IVR. You have a problem somewhere from ignition switch A to wire 297 bk/gr, to wire 30 violet , which goes to plug 13, and then to the IVR. 

The fault may be where wire 30 violet connects to 297 bk/gr. The splice is machine crimped and I don't believe the resistor wire can be soldered- well maybe silver soldered, but not using electrical solder- it just won't stick to the wire. Find the fault and if see if 297, 30 and the other wires in this assembly need to be replaced. Also see the post below. If you need the wire assembly talk to Midlife, and hopefully Randy can help you out: http://midlifeharness.com/

[Mach1 Driver 560]

This is from the wire diagram, page 2-E7. This diagram can be found in the "How tos" section.

FYI, the "blind circuit" where it goes into the plug is just a short section of wire that is put in the terminal with the resistor wire to make a good crimp on the terminal. The resistor wire's gauge is too small to be crimped properly without it. That is a complicated wire assembly that goes to six places, as 297 connects to 904 (another resistor wire) at ignition switch A terminal. Notice where 297A goes to the fuse panel? This could shorten your search- this goes to fuse 1, which is flashers, radio and backup lights. If any of those work then you have power as far as the splice. Also, wire 30 powers the alternator warning light- does it light when the key is turned to ON- not started?

This is from "How Alternators Work" also in the "How tos" section