Electrical Chao

[kpack5982]

After my 3g alternator and mark viii fan install I'm having two annoying problems. First my air bag light now blinks to the code of 12 which means insufficient battery power, but it is all ran with a 4g ground wire and all the other wiring is taken care of and two, my radio fuse blows every time the fan turns on with the fan controller.

All the wiring is connected, but I for the electric fan to get 12v key on power I spliced into the power from the coolant low sensor. Any suggestions?

Oh and more background, the grounds are to where the battery grounded when the battery was in the stock location. It is now in back and the battery is grounded to the fram.

 

[Mike85000]

I haven't looked at that setup specifically, but i don't think tapping a sensor wire to power a fan is a good idea. Are you tapping into it to trigger a relay or to actually run the fan? Also, if the fuse is popping with the fan, it must be overloading the circuit, how do you have the fan wired, in detail??

 

[HISSIN50]

More info on how you wired the system up.

Ensure you don't have a control-wire accidentally hooked to the load side of a relay.

 

[jrichker]

The electrical surge is probably what is kicking the airbag.

If you are good with electrical stuff (90% of the people here aren't), build your own controller. The numbers on the diagram (#86, #87, etc) refer to the numbers on the bottom of a typical automotive relay.

This style relay controller will run the fan with the ignition off to cool down the engine when you shut down. It is a common method used in some of the newer cars.

Note the surge supressor diode on the fan. If you don't copy anything else, copy that. It wll protect your electrical system and may cure the airbag problem.

If you are an experienced electronics tech or electrical engineer, email me and it will send you the prototype drawings of a fan controller that is probably as good as the DC Control unit. It is a build it, troubleshoot it yourself item. I will not build or troubleshoot units, so it is not suitable for anyone who isn't really good with electronics.

 

[kpack5982]

specifically the air bag light came on after I installed the 3g alternator and the radio thing happened after the fan install. I may try a surge surpressing diode, where could I get one?

As far as the fan wiring goes, the fan is wired up as follows, the ground from the fan to the battery ground, the power goes from the battery to the controller with relay which then goes to the battery. There is a ground from the controller/relay to the battery ground as well and the the last wire is from the coolant sensor 12v key on power to the controller. I'm almost wondering if it is a ground issue too because of the battery itself being grounded to the frame. I do have a 4g wire going from the back of the block to the firewall and one going from where the block grounds to the stock battery ground as well, but the ground from the battery it self IS only grounded to the frame in the rear of the vehicle

 

[jrichker]

Read the diagram I posted. The surge supressor diode details are in there.

Rear mounted battery ground wiring. Follow this plan and you will have zero
ground problems.

One 1 gauge or 1/0 gauge wire from battery negative post to a clean shiny spot
on the chassis near the battery. Use a 5/16” bolt and bolt it down to make the
rear ground. Use a 1 gauge or 1/0 gauge wire from the rear ground bolt to a clean
shiny spot on the block.

One 4 gauge wire from the block where you connected the battery ground wire to
the chassis ground where the battery was mounted up front. Use a 5/16” bolt
and bolt down the 4 gauge engine to chassis ground, make sure that it the metal
around the bolt is clean & shiny. This is the alternator power ground.

The computer has a dedicated power ground wire with a cylindrical quick connect
(about 2 ½”long by 1” diameter. It comes out of the wiring harness near the
ignition coil & starter solenoid (or relay). Be sure to bolt it to the chassis ground
in the same place as you bolted the alternator power ground. This is an
absolute don’t overlook it item for EFI cars

Picture courtesy timewarped1972

Crimp or even better, solder the lugs on the all the wire. The local auto stereo
shop will have them if the auto parts store doesn't. Use some heat shrink tubing
to cover the lugs and make things look nice.