Temp guage and blower motor stops at same time?

[Gottolovem]

My buddy just called me and he got back in his car after making a delivery and the blower motor for the heater quit he says that the temp guage stopped at the same time?
Is there a connection between the two?
It's a 1984 t4 with 4a conversion

[dlb]

the blower motor isn't doing anything at all on any of the speed settings? i would check fuses first.

[Gottolovem]

He knows his way around a car real well he checked the fuses inside already but not under the hood.
I don't think that the blower and the temp guage is connected to themselves anywhere in the system?

[dlb]

i wouldn't think they're connected either but if they both stopped working at the same time, that's my first guess. corroded shared ground would be next. next guess is two separate and unrelated problems that just happen to pop up at the exact same time.

[Gottolovem]

So the fuse instrument cluster Is in fact tied to the blower motor somehow.
Pull the fuse and power to cluster and blower motor is cut.
Where should my buddy look for the short the fuse blows immediately upon replacement?
He thinks it's related to the low gas light being not working i disagree His light gas light hasn't worked in two years!

Any ideas?

[dlb]

hmm. i still think it could be a bad ground but it also might be the blower motor has frozen, causing resistance, which blows the fuse when it's turned on. have him replace the fuse, keep the fan switched off, and run the car for a while to see if the temp gauge comes up. if the gauge works then, the problem is definitely on the blower motor side.

i guess on the other end, he could unplug the temp sender wire from the front of the head and see if that keeps the fuse from blowing.

i don't think it's the low fuel light. if the fuel gauge works but the light doesn't, that bulb is probably just dead.

[marlinh]

A bad ground wouldn't blow a fuse. The circuit is incomplete. Looking at the wiring diagram, the power to the instrument panel, energizes the coil side of the heater relay. The heater won't work if that fuse is blown or removed. Which fuse is blowing?

If it is the gauge fuse, maybe there is a short in the cluster? Never seen that myself, maybe mice chewing the insulation somewhere?

[Gottolovem]

Yes it's the instrument cluster fuse that continues to blow.
I can take another cluster out of one of my cars to trouble shoot it

[Gottolovem]

UPDATE
Every time he puts the car in reverse It kills the cluster fuse immediately?
Is the reverse light connected to the cluster?

[marlinh]

The reverse light is powered by the same fuse. There must be a short to ground at or after the reverse switch. Maybe the harness has chafed through somewhere in the engine compartment, or in the hatch harness at the upper right hinge.

[Gottolovem]

Thank's for the tip on where to start looking

[marlinh]

If you can't find anything in the engine compartment, the connector for the rear hatch wiring is behind the right rear trim panel. Hard to get at, but if it was disconnected and your friend tried it, if the fuse doesn't blow the short would be narrowed down. The main connector for the harness that runs to the rear of the car is in the passenger side kick panel and runs along the bottom of the door sill.

[Gottolovem]

Thanks again i suspect the hatch because he is a delivery driver in the hatch opens 30 to 40 times per day for the last two years

[marlinh]

Gottolovem, did your friend fix his fuse problem yet?

[Gottolovem]

Gottolovem, did your friend fix his fuse problem yet?

No my buddy says the fuse has not blown for a while now.
My money is short to ground at the rear hatch loom where it goes from body to hatch it seems to be an intermittent problem and those are the only wires that are getting "moved around" on a regular basis causing the problem to come and go.