1974 Eldorado starter harness

[Semper Fi 74]

I need the starter harness from the starter to the main engine cable for my 74.

[TJ Hopland]

Does 74 still have the 6 pin connector in that harness?   If it does that makes it fairly easy to build a new one since you don't have to splice.

[Semper Fi 74]

Yes it has a 6 pin connector, but it has 4 inline fuses that have blown and I can't tell what amperage they are. The 73 harness that is available does not have the fuses.

[TJ Hopland]

Fuses were not original.  They 3 of the 5 wires are fusible link wires.  I suspect those were one reason they did that connector, its fusible link wire the whole way from the starter to the connector.  If there wasn't a connector there they would (and did) splice from the link wire to regular wire in the same spot the connector was.

I don't have a diagram handy but I believe it says what size the wires and link wires are. Fusible link wires are 2 sizes (4 numbers) smaller than the main wire. If its a 10 gauge wire the link wire would be a #14. You can tell the fusible link wire because its got a more rubbery insulation than the regular wire that is more of a plasic. 

You can buy the fusible link wire online or from parts stores, same with the pins in the connector body, they are kinda known as 'packard 56'.  Its pretty common to have that section of that harness damaged.  At some point someone changed a starter and didn't get the shields and routing so the wires end up touching the exhaust.

If you found a 73 harness for sale that should be the same.

6 pin connector with only 5 being used.  One pin and regular wire goes to the starter terminal that engages the starter.  The other regular wire goes to the other small terminal on the starter that is 'hot' only when the starter is cranking, this wire goes to the ignition coil.  That leaves the 3 fusible link wires that all go to one ring terminal on the fat battery terminal on the starter.  One of these goes to the headlight switch and only feeds the headlights, not tail lights and such.  Another goes to the fuse box for the stuff that is always on.  The last one goes through the key which then feeds the rest of the fuse box for the stuff that comes on with the key.

Knowing that may help understand which may be blown and why some things work and some don't.  WE have had more than a few cases reported here were people did some pretty terrible patches to try and get things jumpered together and sort of working rather than trace out and fix the fusible link which may have just been physically damaged from rubbing on the exhaust rather than an actual electrical failure somewhere in the system.  GM did this 3 link design starting sometime in the 60's and into the later 80's/90's when they started doing the underhood fuse boxes.   

Sometime between 74 and 78 Cad quit using that connector, there were just splices in the 3 link wires and the rest were just part of the main under hood harness.   I have had to at least clean and do minor repairs on every Cad that had that connector so it was a common spot to have issues is maybe why they got rid of it.   I'm sure the main reason it was there was factory assembly,  the starter could be already mounted to the engine with that short harness and just plug in once it got set in the car.    Starting in 75 with the HEI they left out that 5th wire to the coil. 

[Semper Fi 74]

I tried to upload pictures, but they don't show up. My harness has 4 wires, 2 red, one yellow and one grey.

Thank you for your help!

[TJ Hopland]

Does your car have the HEI distributor?  Hei was the coil in cap system?  If it does that would be why the 5th wire isn't there.

Yours doesn't look so good. Is the harness side connector melted too?  I assume it is to kinda match the end in the picture.

Either they changed the lengths or my memory was wrong about how long that harness was.  The inline blobs are the splices between the fusible link wire and regular wire.  I was thinking those were not there on the cars they used the connector on but it looks like I am wrong on that. 

If its just the connector area that is messed up you could just splice the wires there and eliminate the connector.  Like I said Cadillac even figured out that was a problem area and got rid of it.  Every electrical load in the car is running through those 3 wires, mostly 2 since one is the headlights.  That is a lot of stuff for one or two of those little connectors.  They actually do it again at the firewall but at least there its a little more protected. 

I'm sure if you look long enough you could find the exact replacement connector or maybe since you only need 4 of the 6 move things around to use good holes in the one you have?  But that is still a lot of work to be pulling 30+ amps through those little terminals. 

You could look for some other sort of connector but again to be reliable at 30+ amps and fit nicely and be safe down around the exhaust could be tricky and get expensive.  Most cars have no such connector so no great loss if you just get rid of it.   The fusible link wires are still there so things are still protected. 

If someone is selling a 73 harness and you still want to replace it all that should work fine it will just have that extra wire in it.  You will need both ends since I'm sure both sides are damaged so you will be splicing all the wires anyway so that is another reason maybe just splice it and get rid of the connector.   Same amount of work and splices you just don't have to buy the new harness.

[dochawk]

if those are standard inline fuse holders, take the blown fuses to a bright lite.   There's almost always a value etched.

and if someone put fuse holders in, it suggests that the links were blowing.  I'd want to be sure that whatever was solved *before* getting rid of extra fuses like that.

[TJ Hopland]

Those are not fuses its just how the factory did the splices between the 2 different types of wire.

[Semper Fi 74]

Thank you all so much!

[bcroe]

I have seen countless examples of those high
current connectors failing, burning up with age. 
The surface is not noble metal, so in time they
start to oxidise.  The resistance increases,
they start to run warm, they oxidise faster, and
eventually they burn out.  Many of these were
only to aid assembly of the car, so splicing
the wires directly together can solve the problem. 

I am very much a fan of fusible links, that
is what is seen here for a few inches on one
side of the rubber boot, as JTH says.  You
do want to preserve them, or make new ones in
the repair, shortening them half an inch
should be OK. 

Running all those wires down to the heat,
vibration, and moisture in that area was
inviting problems.  My 62 had a big 12V stud
on the inside fender to take them.  No doubt
some bean counter decided to eliminate the
stud by running the wires down to the big
starter 12V stud. 

My cars have that stud added back, the battery
cable goes there, then continues to the starter. 
Note how moving those wires to the fender
eliminates a lot of stress on them.  The smaller
stud nearby is for the big purple wire that
controls the starter.  Bruce Roe