Electrical Problems

02V70 · Post by **02V70** » 19 Mar 2022, 20:46

The dash gauges work intermittently. The ABS, check engine, and other warning lights are constantly illuminated. The text display says brake failure all the time, but the brakes seem to work fine. Also, the air blower or heating and air conditioning do not work.

My dad said this started happening after he took it to a mechanic.

How would I fix this problem?

02V70 · Post by **02V70** » 20 Mar 2022, 12:03

I checked the fuses, and the blower motor fuse was so blown that one of the pins came off, and the plastic was melted. Also, cruise control does not work. I took the dash/gauge-cluster out, and I heard a of rattling. A bunch of bulbs have fallen out. I took them all out, but it did not fix anything.

EDIT:
Also, a bunch of fuses had the wrong rating. I put the correct one in for the blower motor, and that works fine now. Also, the fuse that goes to the ECM, Central Electronic module, and airbags was a 30 instead of 10.

EngineeringBloke · Post by **EngineeringBloke** » 21 Mar 2022, 12:05

You are lucky.

The fuses have different ratings so that the fuse will open the circuit if too much electrical current is flowing in a particular circuit. If a 10 amp fuse is replaced by a 30 amp fuse, then a short in the circuit will allow 3 times more current than is expected before the fuse opens to protect it. This can result in wiring overheating and car fires!

If there is no fault then the higher rated fuse will not cause problems but when a fault happens, instead of just needing a new fuse, you may need costly new parts or even a new car!

A reputable mechanic would not get this so wrong.

But be sure you are reading the owners manual or wiring diagram correctly when you change fuses to different ratings. It might be your mistake and not the prior mechanic.

02V70 · Post by **02V70** » 21 Mar 2022, 12:20

Because the larger fuse would open at a larger current, could short somewhere have compromised the computers, and led to the problem I am having now, or would nothing be functional?

Post by **volvolugnut** » 21 Mar 2022, 12:22

I would do a complete review of ALL FUSES in all of the fuse box locations. If some previous owner or mechanic changed fuses to higher ratings, they may have changed several. Very bad idea.
I have always avoided any used vehicle with signs of wiring changes. They can be heck to find and repair.
Good Luck!
volvolugnut

02V70 · Post by **02V70** » 21 Mar 2022, 12:26

I did to a complete review of all the fuses. The only one I could find that was blown was the one for the blower motor. Many fuses had the wrong amperage for their location. How many fuse box locations are there?

Post by **volvolugnut** » 21 Mar 2022, 13:46

Fuses are under panel at left side under hood, behind panel at left side of dash with door open, and behind carpet panel at left side inside rear hatch.
volvolugnut

02V70 · Post by **02V70** » 21 Mar 2022, 21:42

I took the dash apart and flexed the circuit board to see if anything changed. It did. When I flex it a bit, everything lights up, and when it's not flexed, nothing lights up. I got it to temporarily work, but it always has these error messages shown.

: DSC01009.JPG (1.96 MiB) Viewed 701 times

What could cause all of the errors? Could a problem with the dash also do it? Or are there multiple problems?

Post by **abscate** » 22 Mar 2022, 01:21

Yes, you will need to have that DIM reworked , probably by Xemodex

Post by **jonesg** » 22 Mar 2022, 09:05

It sounds like the circuit board needs reflowing If flexing it brings everything back online. We fixed many old televisions just by doing that.