How to diagnose electric doorlocks?

[ertech]

Hi guys the fuse for the hazards / doorlocks/oil cooler fan kept on blowing .
They are on the same circuit .
I separated the wires going to that fuse with each it’s own fuse .
The only one blowing now is the auto doorlocks .
What part usually shorts ?
The one in the console or the relay inside the dash?
Thanks

[ertech]

I disconnected the console switch near the shifter and still blows
I the replace the door lock relay and still blown.

what should I do next?
thanks

[Alan L]

When does the fuse blow?
When you go to use the locks, or - just when you hook everything up.
If just when using the locks, it may be the system is trying too hard - too much load. The lock system gets stiff and may need freeing up.
Alan

[ertech]

it seems to happen randomly ,

[Alan L]

Then you probably have a short on the + wire. Randomly rubbing on the body somewhere.
You will need to track that wire. One way is to hook a 12V bulb or a horn in to the system instead of the fuse. And wriggle the wires along the track until you can make it short. That will give you an area to look in. But it probably means physically checking the wiring.
Alan

[ertech]

Alan that's a great idea , I learn something every day
will be back next week from vacation and try

thanks

[dannobee]

Try the area in the front of the door jam. The wires go from the top of the door through to the frunk area. Wiggle there and see if it blows.

[Alan L]

Yes - somewhere where there has been movement of the wiring over the decades is the place to start
Alan

[Matt at Pelican Parts]

Could it be a bad microswitch? I know you note that the fuse keeps blowing, which is a pretty good indication of a short. But i found this old thread on a 87 911SC that shows some detail of investigating the root cause of inop electric locks. maybe it could be helpful to you.

-Matt

[ertech]

I disconnected the plug going into the right door see how that goes.
can we use a cheap eBay 2 wire actuator for diagnostic ? the stock one has 4 wires , why?
Matt I dont think its the microswitch since the alarm still works ..thanks

[Groovie Ghoulie]

Check the doors, where the loom runs into the main body. the grommet likes to come off and the wires rub and pinch there. Have you had the doors off for a paint job at any point? usual culprit.

[ertech]

can find the short. . tried all that was sujested .this is what I did so far
1- separated the door lock circuit on its own fuse < usually same fuse for alarm, oil cooler fan>.
2- changed the relay for door locks
3- wiggled all the wires
4- changed the 2 door lock solenoid.
dont this it could be the microswitch since the alarm still works .
5-desconected the round plug going to the doors
6- disconnected the door lock Botton under the radio.

I think the fuse blows while driving
what wire from this diagram could cause it?the red one to the fuse? which else ?

thanks again