electrical snafu

Art Burtt · #1 (**permalink**) 07-13-2003, 08:04 AM

Don,
I've done every thing I can think of to get rear lights to work!!
I have power up to the fuse block inside the car but no power coming through fuse block for rear main harness,except for the wires that power trunk opener and door openers( which I don't plan to install) But, when I turn on the ignition both tail lights light up???? Front lights including signals and headlights work fine. Could I have a bad fuse block? Or has this Ididit column
wiring messed me up? I am totaly frustrated!
Art

Jack21 · #2 (**permalink**) 07-20-2003, 05:48 PM

Art,

Don't despair. Wiring glitches are normal. Between Petek and I, we can dance you through the diagnostics. But to do so, we'll need more specifics, so get out your VOM and tell us where you have juice, and where you don't. I also have an Ididit column and can help there also. The turn signals and emergency flashers are controlled by the column (as well as horn, and headlight dip switch). Tail lights, and brake lights are from different sources.

I only used 2 of the 4 factory relays, all headlights are on separate power, relays, and circuit breakers. Fan is on separate power, dual relay, and breaker. The Ididit column circuits work perfectly. I also hard wired each ground, and terminated them all at a central collecter pannel, and then to the battery ground. Frame grounds are for redundancy only. I have a few soldering tips for you also.

Although it looks like "The Attack of the Spaghetti Monster", each circuit has 2 wires; a +12v, and a ground.

This may be a one shot, or may be somewhat lengthly. If you want to go off line with this, get me on jwalsh21@ix.netcom.com.

Art Burtt · #3 (**permalink**) 07-20-2003, 07:41 PM

Jack,
I have power right up to the fuse block for rear harness but nothing coming thru fuse block to the engine side. The rear main harness works. I hooked a hot lead to each wire and checked
them individually. The two (hot all the time) wires to rear main do get power. These would power the door solenoids and trunk solenoid and they should have power at all times. The front harness works fine I have head lights parking lights and turn signal/flashers. I the only problem is no power coming out of fuse block to the tail/brake lights or turn signals. I figure it has to be a problem with the fuse block. The wires between fuse side and connector side, look like spaghetti,are not numbered and I don't have a wiring diagram for this anyhow. I figure a new fuse block
that has been checked out is the answer. Incidently everything else on the car functions normally. Every circuit has been grounded. The wires coming from the light switch ,#'s 171 and 141
have power up to the fuse side of fuse block,these supposedy
turn on all lights. If I had a guess I'll bet it's one or two wires that are not connected or are connected improperly somewhere in the fuse block itself.

petek · #4 (**permalink**) 07-20-2003, 08:40 PM

Do the front turn signals work ok? How about the emergency flashers?

The front and rear turn signals are on separate switches in the column. The turn signals and emergency flashers are on separate flash circuits.

Art Burtt · #5 (**permalink**) 07-21-2003, 06:27 AM

Petek,
Yes, the front turn signals and flashers work fine as do the head lights. The high beam switch works too! The only problem is no power coming through the fuse block to rear lights.

Jack21 · #6 (**permalink**) 07-21-2003, 07:48 PM

I'm looking at the rear light harness, P3-58, and front light harness P3-63.

On the front harness, wire #167 goes to the front right turn light, #168 to the left turn light, and #147 to the front parking lights. And you're saying that these work. And the emergency flashers work.

On the rear harness, #169 goes to the left turn, #170 to the right turn, #147 to the parking lights, and #165 to the brake lights.

If you have discontinuity at the fuse block, a fix might be to splice #'s 169 & 168 for left turn, 170 & 167 for right turn, front #147 and rear #147 for parking. Do this on the engine side of the firewall. No permanent connections until everything works.

If no power on the engine side of firewall to #165 which is your brake light wire, drill a small hole through the firewall under, or alongside the fuse box. Take the #165 wire where it does have power from the fused circuit, connect it to a short length of wire and push it through the hole you just drilled (1/8" - 3/32") and connect to #165 on engine side of firewall.

Everything should now work. Trial assemble this and tell us what happens.

Petek, do you agree with this?

Art Burtt · #7 (**permalink**) 07-21-2003, 09:18 PM

New fuse block is on it's way from Don. If it works when installed we'll know original one was screwed up.

petek · #8 (**permalink**) 07-22-2003, 07:42 AM

Sounds like a great way to bypass the problem Jack. Should work fine and w/o any problems.

I'm still wracking my brain on this one. The problem could be in the fuse box as Art says ... or the problem could be in the column switch.

Art, if the new fuse box doesn't work give a holler and I'll see if I can find the pin-outs to the column switch and walk you through bypassing the column to test the lights.

Art Burtt · #9 (**permalink**) 07-22-2003, 08:07 AM

Steering column switch seems to be okay as it operates front turn signals,flashers,and low and high beam head lights. I found a wire on the transmission harness that was barely stripped back enough to make contact. It was one of the main power wires coming into fuse block on engine side of the fuse block. I repaired that one so I'm thinking this could be the problem inside the fuse block itself. It is almost impossible to see which wire goes where
even if you pull the fuse block apart. This wire supplier leaves a lot to be deisired in the construction of his product.

Art Burtt · #10 (**permalink**) 07-25-2003, 09:20 PM

Oops! New fuse block same problem!!! What now? And why?
I talked with Don at length today and he's stumped too!!
I guess the kit car gods are really pissed at me!!!

petek · #11 (**permalink**) 07-26-2003, 01:54 PM

The switch in the steering column has separate contacts for the rear signals. I'll check my notes and see if I can find the pinout.

Heck the turn signal switch is about the only thing left!

Art Burtt · #12 (**permalink**) 07-26-2003, 02:13 PM

Petek,
Don and I went over that all wires are in correct order and hooked up to the correct wires on fuse block. Front turn signals and flashers work. Now I have developed a new problem,when I turn on the ignition switch the tail lights come on irregardless if the light switch is on or not. Rear turn signals and flashers do not work.
This new one has me stumped??? Think I'll buy a Ford Lightning P/U and say the hell with a Cobra!

TomH · #13 (**permalink**) 07-26-2003, 05:47 PM

Art,

Does your VOM/Test Light "see" current immediately behind the fuse block? (Behind = Tail Lamp side) Can you disconnect the tail lamp at the fuse block and light it with a hot wire from the battery or other known good power source?

petek · #14 (**permalink**) 07-26-2003, 09:16 PM

Art,

Don't give up ... the solution is there somewhere.

Since I have a Painless wiring harness I'm going to have to sit down with the Classic Roadsters manual and see if I can puzzle out what they did. I'll see if I can set aside some time tomorrow and get back with you.

Just remember, it all comes down to a ground and a hot ...

petek · #15 (**permalink**) 07-29-2003, 08:20 PM

Didn't forget about you Art ... it took me a little bit of time to find my CR manual and take a look at the wiring.

Do you have an DVM (digital volt-ohm meter) or simply just an ohm meter?

Take a look at page 3-73 in the CR manual. The steering column pigtail harness. What I'd like you to do is disconnect the +12 from the battery and pull the flat connector from the steering column.

Once the batter is disconnected and the connector is pulled from the steering column, measure the resistance (ohms) from circuit 169 or circuit 170 to ground. You should see a few ohms (10's, maybe 100's) of resistance. The resistance is the cold filament resistance of the tail light bulbs.

If you don't have a meter, give a yell and I'll come up with another test. The test above will isolate the problem to 1/2 of the system and we can go from there.

Art Burtt · #16 (**permalink**) 08-19-2003, 07:58 AM

Finally solved electrical problems. Thank you Painless wiring systems!!!