Questionthe auxiliary fans were rigged up to run all the time. the wire burned up. was tapped into the wiring harness that leads from the left auxiliary fan to the connection coming from the fan resistor - near the left front of engine near the abs control module reservoir-whatever its called.
i repaired the damaged wiring harness and plugged it back into the fitting which receives power from the fuse, auxiliary fan relay, and the preresistor auxiliary fan relay. there are two fan relays and a fuse. i changed both relays and fuses.
i have power from fuse to both relays at the fuse/relay box. but nothing coming out of it. it should lead down to a black wire - from auxiliary fan relay to the preresistor located near the left front abs module area.
i have no power with key on (start), and no power from the other preresistor relay in the fuse/relay box which is suppose to lead down a .75 brown/blue wire - and a second 2.5 black purple wire - which leads to the preresistor - down to the auxiliary fan harness.
i bought two new relays. how do i check and recheck them? this is where i think i will find the solution.
nothing is being sent out of the relays. i am using the e-class owners bible-bentley publishers and the alldatadiy.com which has provided me with some major knowledge. please help as the coolant temp gauge is starting to max out.
AnswerRaymond,
A bit dizzying to follow. But you may have damage up stream of the fuse block. Over time, the harness may have gotten hot and cause a short internally. The relays are activated by 12 volts. You should be able to determine which leads go to the trip magnet, as it should be stamped on the side if the relay has an aluminum case. I would also take a look at all the fuses in the fuse box, as they sometime get corroded on each end and cause bad connections and high resistance. I would purchase copper slug fuses and replace all of them after cleaning the sockets with a fine emery cloth or similar fine product.
Have you checked the Over Voltage Relay fuse? It may be on the firewall and will have a red top with a fuse there. Why were the fans rigged to operate all the time?
You could directly create a jumper wire to the fans and to the battery to determine if they are operating properly. If the insulation was burned off then the fans may be bad and drawing too much current or have a bad connecting joint with high resistance. Either could cause the wires to get too hot and burn off the insulation.
Good Luck. Let us know how things go.
Robert
