[alfaseb]

The week-end was going fabulously well as I had finally managed to bring the spider to life with its new carbs and fuel set-up (converted from Spica) until the point when I turned the ignition key to restart the car (after adjusting the carbs mixt. screws) and absolutely nothing happened. no clicks, no power switched or not. So I started checking around my grounds, my fuses, and took out the voltmeter to make sure my battery was charged (it is). Then I went to check that I had power at the starter solenoid and discovered something I don't understand:
if I disconnect the positive battery cable connected to the starter I can confirm that it's hot however as soon as I re-attach it to the starter terminal I get something like 0.8v using the same ground I used to test the freed cable.

So, can someone please explain to me how I can loose 13 volts by simply hooking the battery cable to the starter before I fry the few neurons I have in my electrically-challenged brain? Could this be caused by a short within starter/solenoid?

Thanks!!!!!!!!

 

[papajam]

Clean the battery cable ends at the battery.

I'll need your email address to send you the diagram.

 

[Alfacliff]

if it were a short, there would be a large spark when you connected the wire. check the voltage bwtween the - terminal of the battery and the engine. check the voltage between the + terminal of the battery and the top bolt on the solenoid where it connects, the wires may be corroded inside the insulation. an ohm meter passes very little current to read resistance. a bad connection can drop a lot of volts with some current flow.
cliff

 

[alfaseb]

I swear I hear the Twilight Zone theme song when I come close to the spider....

Do call me crazy but I have determined that I loose the voltage (drops from 12.9v to 0.8v) when I attach the hot wire going to the fuse box...yeah I know, loony... anyway, I'm 100% sure that my voltage issue has nothing to do with the battery connections/cables as I've tested them every which way. I also determine that I get this 0.8v all the way (thru the fuse holder) to the red terminal on the ignition switch. Oh and I hear/see no arcing or smell no burning.

Could it be a malfunctioning relay somewhere? I see what I think is the starter relay on the firewall next to the coil. What role does it play and how can I test it? Any other suggestions?

Thx!!!!!!!!!

 

[Alfacliff]

there is a wire from the starter to the fuse box, it is the smaller wire on the top lug, the battery cable connects to the lug also. if there is corrosion or a bad connection to this cable, there is poor connection to the rest of the car. on my 74 spider, the wire goes to the terminal strip under the battery, then to the fuse box.
cliff

 

[alfaseb]

Cliff, Jim,
I ran a (confirmed) hot wire from the battery to the fuse box and I still get this weird 0.8v at the fuse box which tells me the cable from the starter to the fuse box isn't defective. What can be sucking this voltage? and no, the car is not on fire...

Thanks.

 

[Alfacliff]

is there .8 volts on the battery? check if the battery is bad. sometimes the interconnections of a new or not so new battery get loose and the battery is bad. this is with a load, like turning on the parking lights.
cliff

 

[alfaseb]

nope, battery is brand new and gives me at least 12.8v.

I just thought of one thing, I recently cut off and caped as it leaves the prong on the engine side of the starter solenoid the black wire going to the CSS as it's no longer used (carbs). Because I capped it with a twist on I'm quite certain it's not coming in contact with the block (otherwise I would expect to see that nice spark), right?

 

[Alfacliff]

spark and smoke. if a wire direct from the battery to the fuse box gives only .8 volts then either the battery is bad or the ground.measure from - on battery to engine with parking lights on, should be still very low volts. check from battery to fuse box with parking lights on, should also be very low voltage.this will check the condition of the wireing to ground and to fuse box.
cliff

 

[alfaseb]

cliff, how patient are you???? ;-)
scenario 1. with + battery cable to starter solenoid post and no connection to the fuse box I read 12.8v between the solenoid post and the engine block.
scenario 2. same as 1 above but I hook up the red cable from the fuse box to the same post on the starter solenoid and when I try reading between the solenoid post and the engine block I get 0.8v.
scenario 3. I run a jumper from the battery + to driver footwell and measure voltage between wire and left side of dash ground that I get 12.8v.
scenario 4. same as 3 but I connect + jumper to back side of fuse box at fuse 2 and I read... 0.8v

Arghhh!!!!!!!!

 

[Alfacliff]

you have a bad connection there somewhere.either on the + or-. the best way I have found is to put on a little draw, like the parking lights and check for voltage drops. a bad connection will drop the voltage and be a lot more noticeable than measuring with an ohm meter. even measuring between the battery terminals and clamps will show bad connections if there is current flowing.
cliff

 

[alfaseb]

the problem is I have no voltage at the fuse box so I can't even turn on the lights or the turn signals. Thick me is starting to realize that it's likely a ground issue and it's open somewhere but where...

 

[alfaseb]

SOLVED -You were right, bad ground!

Cliff, Jim,
As usual you were right. It turned out to be a bad ground right at the battery. I took all the grounds I could find apart and brushed/cleaned every electrical connection I could put my hands on. Hey, I even found that big interlock plug that had been tucked away far inside the dashboard...
So, thanks again guys!

Now, on to timing specs for this spica to carb conversion...