kenmosher

My recently acquired 1970 W-31 has a combination of 47 year old wiring and connectors (I call it OCS ... old car sh*t ) and hack jobs by former owners over the years.

I started the project to replace the base gauges with the Rallye Pack and it's been reasonably successful ...

1. Found dash lights didn't work and finallly traced it back to the green wire off the light switch being broken. Fixed it and viola ... MOST of the dash lights worked and traced a bad ground off the heater bulb being loose to make the rest work!
2. Found the pass turn signal "bucket" had a dead short in the connector. New bucket solved that
3. Found the left turn signal would blow the directional fuse if the lights were on. Traced back to bad/corroded bulb base in driver's side signal bulb. New bulb and some WD40 fixed that.
4. Rewired the connectors for the Rallye Pack gauges as the EXCELLENT reference on this site showed. Also pinned out the new gauges to verify (and all good ... these repros are nice!)
5. Installed the Tick Tock Tach ... debugged stupid issue with the instrument lights (found another bad ground in the dash light circuit ... although after chasing the light switch for an hour, I still suspect it is a little flaky because if you wiggle it sometimes it can cause dash lights to flicker. Also if you pull it all the way out to the stop, sometime dash lights don't come on until you push it in just *slightly*)
6. Found a cut wire that explained why the back pass side turn signal/brake lights didn't work. Fixed it. Why it was cut? No idea...
7. Fuel gauge doesn't appear to be working right (shows over full) so I'm suspecting either a bad ground at the tank or a bad sender. I'll do some more investigation here shortly.
8. Oil pressure switch is missing and a cam plug is jammed in the oil pump hole (and stripped, oh goody ), so I'll tackle that project later with drills, EZ outs and heat. I've lost patience at this point and need to take a break!

SO, with that windy background... a couple questions:

1. I've got some strangeness with the flasher now (I think) ... the 4 ways work fine (finally) after reseating the flasher and chasing all the bad grounds and bulb sockets.
   
   I used WD40 in all the bulb sockets and connectors and reseated everything. HOWEVER ... turn signals (both left and right) won't flash ... they just light the appropriate filaments (i.e. right turn and front pass signal light turns on, rear signal light turns on, indicator on instrument panel, and stays on ... no blink). What puzzles me is that the four way flashers work fine (and are pretty quick? Not enough load?)! I'm leaning towards it being a bad flasher (and I'll pick one up here in a bit just to try ... they're cheap). BUT ... any other ideas of where to look?
2. Am I right in assuming the fuel gauge wiring is 12V to one side of the gauge -> fuel gauge windings->Sender wire (tan) to sender/trunk -> Sender (resistor) and then finally GROUND at the tank? Figure I'd start with the tank ground and work backwards ... bad grounds seem to be a "theme" with the car!

Once I get the last electrical gremlins put to bed, I can drive it and enjoy it before tackling the oil pressure sender nightmare.

mrolds69

On the flashers...there are 2 separate flashers, 1 for the 4-way on the fuse box, and another for the turn signals.

oldcutlass

The one for the turn signals hang off a pigtail by the steering column.

joe_padavano

For completeness, the turn signal flasher module is on a pigtail behind the dash to the left of the steering column, sort of behind the wiper switch. The flasher is supposed to be snapped into a clip attached to the metal lower dash, but frequently it is loose.

Fun71

I had the issue of the fuel gauge showing way past FULL on my 70 and 71. On both cars it was a poor connection on the input of the tank sending unit. If I reached behind the license plate and wiggled the brown wire, the gauge would read correctly. On the 70 I dropped the tank and tightened the bullet connector and resolved the issue; on the 71 I am older and lazy so I just wiggle the wire when the gauge reads wrong. Maybe one day I'll drop the tank and tighten the bullet connector, but I'm not committing to anything...

kenmosher

Great info! I didn't see the second flasher on the wiring diagram. Looks like illl have to dig around some more and find it.

Ill bet thats it ... and probably the result of me rooting around back there. Hopefully get it finished up and then move on to the fuel sender problem. Thanks again!

kenmosher

Update: that did the trick! Found the othe flasher (which had scorched terminals). Pryed it off the connector and put the spare I had in. Works like a champ!

Now lights all work, tach and clock work, signals work, even all courtesy lights and console lights work!

Car shifts right (redid vacuum lines and corrected a bunch of leaks) and I realigned steering wheel too. Fun! That little 350 screams to redline (6000 rpm!).

Left ft on the list:

1. troubleshoot fuel gauge wiring/sender
2. troubleshoot temp gauge. It's stuck on cold but does cycle with key on (I haven't cut the green wire yet)
3. gotta get some radial tires! The Firestone wide ovals look period but are really horrible!
4. after some miles, I think I'll replace the header back exhaust.

Thanks folks for for the insight! Saved me a lot of headaches!

kenmosher

Update (again)...

Temp gauge works now... found the old switch was actually plugged into the trans solenoid plug ... (looks like some primitive spark retard mechanism for early emissions?) SO, unwrapped a metric mile of electrical tape wrapped harness and found the actual temp sensor (and oil pressure switch) wires clipped back in the mess. Brought those back out (and rewrapped the wire harness with some nice anti abrasive mesh conduit covering I had from another project) and viola! Temp gauge is reading!

Dropped the tank and have a new fuel sending unit on the way to hopefully put that one to bed too! Should be here Wednesday...

Then it's just the oil pressure thing ... any advice there? The cam plug that's screwed in the hole must've been Loc-tited or something. The hex portion is rounded, so I can't get a grip...

My plan is to:

1. Drill through the plug CAREFULLY while vacuuming metal shavings until almost through. Then put a big dab of grease there to catch the final little bit of shavings when the bit breaks through.
2. Use a series of EZ outs to try and get the plug to break free and just screw out (ideal)
3. If it won't screw out, drill out the remainder and retap the hole (PITA)

Question: How big is the oil galley under there? If I have to go slightly larger and then heli-coil (threadzert or whatever) will I bugger up the block?

oldcutlass

You should be able to grip it with channel locks, vise grips, small pipe wrench, etc.

joe_padavano

Don't bet on it. Picture an allen head pipe plug in place of this tee fitting. You have the front cover sticking up on one side and the intake on the other side. Even if the pipe plug sticks up from the block, no took will be able to fit in there and grab it.

oldcutlass

I miss understood I thought he was trying to remove the sender.

kenmosher

Yup... wish the sender was there instead of the recessed plug... *DOH*!

oldcutlass

You should be able to drill a hole and then use an easy out.

kenmosher

Cool ... that's my plan.

UPDATE: It was the sending unit ... dropped the tank, tested a new one and fuel gauge works! Just wrestling stuff back up in position and should be good to go!

Next ... oil pressure sender () ... going to do a bit of noodling to make sure I have the right easy outs and so on. Won't hurt anything to drive it a bit without oil pressure showing on the dash.

Thanks again for the help folks!