Mlunsford33

1970 oldsmobile cutlass 350 where does all these wires go can someone please help

Mlunsford33

Mlunsford33

Mlunsford33

PatL

The one you are holding in your hand is the engine harness, plugs into the oil and temp senders, alternator, horn relay, starter, etc. The other plug on the firewall (from memory I believe is the front light harness

Mlunsford33

Okay are they supposed too have plugs on them and where do they plug in at thanks for the reply

oldcutlass

The plug to the alternator in the first picture, the one in your hand, and single plug with the blue wire go to the wiper motor and washer. I'll have to check on the rest when I find a diagram.

Mlunsford33

Okay thanks alot for the help

oldcutlass

I believe this is the diagram for your car. Everything on the left side is from the 2 connectors at the firewall. You have an internally regulated alternator so there is another mod you need to do for that wiring.

joe_padavano

This is the remains of the original voltage regulator. The alternator on your car is not the original one, it's a later 10SI or 12SI with an internal regulator. The pictures of the wiring tell me that whoever worked on this was completely clueless. You'll need to make wiring mods to use that alternator. Those mods will bypass the regulator in your hand. Right now there is no way to know if that has been done yet or not. And as noted, the yellow and black wires plugged into your alternator in the first photo are NOT supposed to be there. That will either blow out the alternator or start a fire.

Vintage Chief

Aside from the information previous CO members have provided but in particular the identification of the non-original alternator by Joe and the voltage regulator in your hand (and confusing/remaining wiring), you should:

(1) Purchase a Paperback copy of the GM 1970 Oldsmobile Chassis Service Manual (CSM) at the very least which provides the necessary wiring diagrams and all information required to fully service your vehicle. You can find them on various Internet sites for various prices. Here are several for sale with a quick search.
https://www.ebay.com/itm/1970-Oldsmo...5.c10#viTabs_0
https://www.ebay.com/itm/1970-Oldsmo...MAAOSwEShc2jj5
https://www.ebay.com/itm/1970-Oldsmo...AAAOSwNjxbu~5M
https://www.ebay.com/itm/1970-Oldsmo...cAAOSwn2pcgZeK

(2) Consider the purchase of a GM 1970 Oldsmobile Cutlass - 442 Factory Assembly Manual (FAM). Many of these are available via CD and/or otherwise - (e.g. paperback). The FAM identifies the location of every part on the vehicle. I assume you can search for this item on your own. It's included in the last URL link I provided in (1) above.

(3) I would open up the entire wiring loom you are holding in your hand in the above picture, and any other wiring looms leading from the firewall. Employing the wiring diagram contained in the CSM (or using the one Eric provided at the minimum), review, examine and label every wire in each wiring loom with a piece of painters tape and marker so that you have a complete and clear understanding of every wire in each wiring loom. It might appear tedious (it is), but you'll know unequivocally the identification of every wire. This is, IMO, absolutely critical. Examine every wire for splices and bare spots for rubbing, chafing, etc. and create new, sturdy splices (ensure you use heat shrink). Then re-wrap your wiring looms. The confidence you'll gain in the wiring can't be underestimated.

Good Luck!

Mlunsford33

Thank you so much