Hi All,

I'm new to the forum and new to owning an old truck having just bought "Hulk" about a week ago (wife named the truck because of original interior color).

There's a laundry list of issues with the truck but I'm hoping to tackle them one (or two) at a time.

The one I'd like to try and tackle is that there are no lights behind the gauges and the only light that seems to work period is the left turn light.

I took the instrument cluster out, cleaned and tested the printed circuit board and found it dud (only one or two of the lines conducting using a continuity tester). I've managed to save one from a salvage yard and after cleaning up all looks good. The white plastic backing disintegrated during the saving and the one in my truck is no good too, so I've ordered a new one from Bronco Graveyard.

My question would be how to I remove the existing gauges from the truck I have and fit them to the new backing? I haven't tried anything yet because of the falling apart backing in the truck now and not having a new one, so is it going to be real simple?

Apologies for the long winded explanation but my experience with forums is to give as much info up front to help with getting a clear answer!

Any and all help welcomed!!!

 

It is very easy to remove the gauges. There are nuts on two studs on the gauges, other than the speedometer. There is a plastic cover over the studs on the oil & amp gauges, the cover will pry right off with a screwdriver.

The speedometer is held on by two small bolts. Remove those & the speedo will pop out.

Be sure to paint the needles on the gauges before you reassemble everything. They look so much better when they are bright orange.

 

1976 F100/350: TWO different printed circuit boards, TWO different instrument cluster backs!

 

Sounds fairly simple! It's just that this is my first time owning/working in one of these trucks and my first project truck. I'm already blundering my way through most of it so want to make sure certain things are sorted first time!

 

Yeah reading through various sites I've figured out the warning lights versus gauges backs and circuit boards. I've got the gauges and not the warning lights so I'm pretty sure I've managed to get the right circuit board and backing. It's the circuit with 8 lamp connections and four sets of connections for the gauges and then the Speedo in the middle.

 

D6TZ-10K843-B .. Printed Circuit Board-Use with Oil/Amp Gauges / Marked: D6TF-10C956-BA / Obsolete ~ 5 available NOS

1976/79 F100/350 - 1976/91 Econoline - 1978/79 Bronco.
------------------------------------------------------------------
E1PZ-10848-A .. Hard Plastic Instrument Cluster Back-Use with Oil/Amp Gauges / Obsolete

Introduced in 1981 Econoline, this was also the "service part replacement" for the POS composition cluster back that can TURN TO DUST before your very eyes!

1981/91 Econoline, service part replacement: 1976/79 F100/350 - 1976/80 Econoline - 1978/79 Bronco.

Dennis Carpenter bought all of FoMoCo's remaining inventory, currently has 83 (800-476-9653 / 704-786-8139).

 

I have a question about this number dummy or who ever. Have a 77 f100 and I think the cluster has been changed, but the signal light arrows light up only when the lights are on and they flash when I signal when the lights are off. Would you guess the cluster has been changed or do I have different problems then that. Thanks

 

keirobi, Also make sure to replace all the bulbs with new, & clean the contacts on the bulb holders. Nothing is worse than putting the cluster back in & finding a bad bulb or holder. Put a drop of light oil on the back of the speedo where the speedo cable hooks up while it is apart too.

 

Thanks scottscott I'll make sure to change bulbs and clean holders. The clip for the Speedo cable is broken so it slides on easy enough but just want to be damned sure this cluster is good!

 

Thanks scottscott I'll make sure to change bulbs and clean holders. The clip for the Speedo cable is broken so it slides on easy enough but just want to be damned sure this cluster is good!

 

Clean the contacts at all the exterior bulbs, front & rear - the problem is more likely in one of those bulb sockets than at the cluster.

 

OK, so quick update. I finally received the white cluster backing and got the cluster put back together. Replaced all bulbs, checked all connections and everything checked out ok. Put the whole thing back into the truck and I've still got no lights behind the gauges when I put the lights on. The right turn signal works fine, but the left one doesn't come on at all.
I thought it was all good when I put it in, but now I'm second guessing myself. Could it be a dodgy connection in the plug that connects to the instrument cluster or something else?
Any suggestions? The gauges seem to be working fine (tested off the cluster with voltage put across them) in the cluster, so it's just the lights I think...

 

I'm not sure this is your issue, but is worth checking into. I had this exact situation on a Ford cluster and it had me scratching my head for a bit until I figured it out.
There are 2 different 194 bulb holders listed for a Ford. Here is one style:
http://www.ebay.com/itm/6-FORD-CHEVY-DODGE-OLDS-INSTRUMENT-PANEL-1-2-DASH-LIGHT-BULB-SOCKET-194-168-EU-/331367309125?hash=item4d2707df45&vxp=mtr

Here is another style:
http://www.ebay.com/itm/6x-Ford-194-Instrument-Panel-Cluster-Light-Bulb-Lamp-Dashboard-Socket-Plug-NOS-/270988913895?hash=item3f1832ace7&vxp=mtr

Note on the last one that the contact nibs are larger and moved to the outside of the contact. The first one listed has smaller nibs that are moved inward on the contact. On an early Ford, you want the large tabs on the outside of the contact so it makes a connection with the printed circuit.

 

ronsplov - I had no idea about the two different types of bulb holder. Certainly an eye opener and something I'm going to check for tomorrow.
On a related note - does anyone have a wiring diagram/list for the connector socket that goes onto the back of the cluster? I'm also wanting to check that I'm getting the right voltage to each of the pins to make sure there's not something funny going on with that. Tried it out the other day and found that some of the gauges aren't working correctly now either, but I double checked the "new" circuit board that went in and it was all A OK??? Scratching my noggin on this one that's for sure!
Anyone had something similar or got any advice?

 

Maybe this will help?